Scielo RSS <![CDATA[Salud mental]]> vol. 28 num. 3 lang. es <![CDATA[SciELO Logo]]> <![CDATA[Alteraciones anatómico-funcionales en el trastorno por déficit de la atención con hiperactividad]]> resumen está disponible en el texto completo<hr/>Abstract: The most recent technologies of cerebral imaging provide new data about cerebral abnormalities in patients with diverse psychiatric disorders. These methods include computed tomography (CT), magnetic resonance (MRI), electro magnetic (EMEKG), functional magnetic resonance (MRIf), positron emission tomography (PET), single photon emission computed tomography (SPECT), quantitative electroencephalography (QEEG), and evoked potentials (Eps), among others. Illnesses such as anxiety disorders, depressive disorders, dementing disorders, obsessive compulsive disorder, schizophrenia, bipolar disorder, learning disorders, and attention-deficit/ hyperactivity disorder (ADHD), are now considered the result of an interaction between environmental factors and abnormal function and structure of the brain. Data obtained from studies in ADHD subjects indicate a biological basis for this disorder. The specific anatomical and functional alterations of the brain in these patients, has been possible thanks to neuro-imaging. Satterfield &amp; Dawson, in 1971, were pioneers proposing that the ADHD symptoms were related to a malfunction of the fronto-limbic circuits. They said that the normal fronto- cortical inhibitory control exerted over the limbic system is weak in patients with ADHD. This hypothesis was known as the "fronto limbic hypothesis of ADHD"; although, the results of the research derived from diverse disciplines such as neuropsychology, neuro-imaging, and neuro biochemistry, suggest that Satterfield &amp; Dawson were partially right, in fact the neurobiology of ADHD would be more complex than they originally supposed. Almost every research done with neuropsychological methods in ADHD patients points to the same results: a malfunction in the frontal cortex. Damage in the orbital area of the human frontal cortex produ ces social disinhibition and impulsivity; also injury to dorsolateral prefrontal cortex (DLPFC), causes deficit in the ability of behavioral organization, planning, working memory and attention. The findings of neuropsychological research point toward dysfunction to the orbito frontal cortex and DLPFC in subjects with ADHD. With the advance of the new neuroimaging techniques, the results delivered from the clinical and neuropsychological observations can be validated; when used in combination they can give us detailed information about the anatomic areas involved. The early structural studies made in subjects with ADHD were done using CT. Unfortunately the poor resolution and the lack of quantitative measurement of the CT, besides of the small sample size of subjects using diverse methods of clinical diagnosis, and the difficulty to find healthy controls; made the results of these early studies with CT inconsistent. The results reported by different authors were contradictory, since some of them reported no abnormality at all in subjects with ADHD, and some others found frontal and cerebellar atrophy in patients with ADHD. The studies made with MRI improved the quality of the structural studies done in subjects with ADHD. At the same time, the improvement of the diagnostic tools in regard to validity and reliability, and the inclusion of adequate control groups; made the results obtained from these new studies to overcome the deficits of the studies that were made with CT. The studies made with MRI found a decrease in the size of corpus callosum, basal ganglia, particularly in left globus pallidus, and cerebellum; and atrophy of the right frontal cortex and a change in the total cerebral volume. On the other hand the studies made with techniques such as PET, SPECT and functional magnetic resonance, have found a decrease in cerebral blood flow (CBF) in the frontal lobes, striatum and cerebellum in subjects with ADHD. The studies with SPECT made by several groups of researchers have shown increase of the CBF frontal cortex and the caudate nucleus, and decrease of the CBF of the occipital cortex; however, almost all these studies included small sample sizes and used inadequate control groups. Other studies made with PET in adults with ADHD have shown a decrease of the metabolism of the frontal cortex; however, different groups of researchers have reported different findings, possibly due to methodological variations across the studies. Again the majority of these studies used small sample sizes. The studies made with MRIf show that the fronto-stratial circuits work differently in subjects with ADHD when they are compared with controls. Again almost all the published studies included a small sample size. In particular, the results from the studies done by Bush C. et al in 1999 using MRIf combined with a neuropsychological test named "Counting Stroop", showed a lack of activation of the anterior cingulate gyrus in subjects with ADHD compared with controls. The PET technology can study the brain chemistry invivo. Some researchers have found a decrease ofdopamine reuptake in the prefrontal and medial cortex and an increase in the mesencephalon in patients with ADHD. Some studies have found an increase of the dopamine transporter density in the striatum in subjects with ADHD. In conclusion: the neuropsychological studies and the studies of neuroimaging, suggest that the fronto-stratial circuit in the right side plus the cerebellar influence are involved in the neurobiology of ADHD. The cortex-striatum-thalamic circuit selects, starts and executes cognitive and motor complex responses, and the cerebellar circuits provide the guide for these functions. The hypothetical implications of the data contributed by the findings with neuroimaging techniques in ADAH are at this time only tentative. Reproduction of this data for independent researchers is needed. Besides, it is necessary to perform more detailed subdivisions of the brain areas implicated in ADHD. The low statistical power due to the cohort small size included in almost all of these studies is an important problem because of the high anatomical variability of brain measurements. Besides just a few of the published studies controlled the previous exposure to medications for ADHD. Finally, there are no studies in other circuits that play a role in the attention such as those formed by the thalamic pulvinar, the parietal inferior cortex, the primary sensory area, and the postero-inferior parietal cortex. However, the research using methods of structural and functional imaging surely will be valuable in the future, in order to improve our understanding of the anatomical and functional physiopathology ofADHD and ofthe other psychiatric disorders. <![CDATA[Evaluación de la relación entre rasgos psicopatológicos de la personalidad y la calidad del sueño]]> resumen está disponible en el texto completo<hr/>Abstract: Introduction. Diverse studies llave demonstrated the relationship between psychopathology and sleep alterations. Data proceeding from the ambulatory psychiatric field show that 70-75% of the patients experience sleep problems. The most frequent complaints refer to nighttime sleep alterations, excessive daytime sleep, difficulty with morning waking, and disturbances in the circadian rhythm of the sleep-wake cycle. Many studies, most of which use patient samples, have associated psychopathological personality traits and sleep disorders. All of these studies reveal that subjects with sleep disorder tend to be characterized by psychopathological traits (anxiety, psychasthenia, depression, etc.). There is some evidence that the structure of some dream dysfunctions (such as insomnia) is similar among general population and psychiatric samples; differences are more quantitative than qualitative. In samples of university students, the percentage of individuals who report bad sleep quality has been similar to the percentage of insomniacs in general population. With the aim to delve more deeply into the analogy between the sleep quality of normal subjects and clinical samples, and given the shortage of studies relating psychopathological traits of personality and sleep quality in normal population, this study intends to explore the relationship between the psychopathological personality variables included in the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) and the sleep quality evaluated with the Pittsburg Sleep Quality Index in a sample ofsubjects who have no diagnosed sleep disorder. The psychopathological variables included in the MMPI-2 which predict sleep quality in a non-clinical sample are also determined. Methodology. A sample of 222 individuals (186 women and 36 men) with a mean age of 21.65 years (SD=2.81) completes the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) and the Pittsburg Sleep Quality Index (PSQI), which provide an overall sleep quality measure and seven partial scores for different dimensions: Subjective sleep quality, Sleep latency, Sleep duration, Sleep habit efficiency, Sleep alterations, the use of hypnotic medication, and daytime dysfunction. Results. Some psychopathological traits (hypochondria, anxiety, and depression) correlate positively with almost all of the sleep quality dimensions comprising the PSQI. From a logistic regression model developed to predict the probability of being a good or bad sleeper, hypochondria and anxiety are the only statistically significant predictors. Discussion and conclusions. Human sleep, from a behavioral perspective, would be explained from four different dimensions: Circadian time (sleep-wake cycle situation on the nictemero), Organism (intrinsic factors such as age, sleep patterns, emotional states, etc.), Behavior (facilitating or inhibiting behaviors), and Environment (temperature, light, noise, etc.). Psychopathological personality traits, the main objective of this study, can also be included within the second component (organism). Previous studies using the MMPI have associated insomnia to high anxiety levels, depression, hypochondria, hysteria, and psychasthenia. The MMPI has also been considered to be a useful instrument in identifying different personality profiles ininsomnia subjects. There are, however, only a few studies focusing on the relationship between these personality traits and sleep quality in normal subjects. The results indicate that this study sample the subjects do not present serious sleep disorders. All of the components pertaining to the Pittsburg Sleep Quality Index present mean scores below the middle response range, situated in 1.5. However, if we consider the total score and bear in mind that a score of five is the cut-off point used to differentiate good sleepers from bad sleepers, we can classify 45.94% of the sample as bad sleepers. In considering the scores for the different MMPI-2 clinical scales, we should mention that none of them reached the typical score of 60; therefore no trait was found to be clinically significant. Some psychopathological traits are linked to almost all of the sleep quality dimensions. Hypochondria, anxiety, and depression are present in the associations with subjective sleep quality, disturbances, or daytime sleepiness. Though no stronger relations between use of hypnotic medication and psychopathological traits have been found (none of them above 0.30), a similar trend on patients dependent on benzodiazepines (predominating traits as depression, psychasthenia and schizophrenia) has been showed. It is also important to point out the relationship between daily dysfunction and the WRK scale (work interferences), which reveals the negative effects of daytime sleepiness, even in subjects who do not present important sleep disorders, as in this sample. On the other hand, the relationship between daily dysfunction and hypochondria, depression, and schizophrenia found in this study has previously been verified in patients with excessive daytime sleepiness. When considering the global score, we can clearly inform that health concerns (reflected in the Hs, HEA, and Hy scales) and the negative emotional states (D, ANX, and DEP scales) are related to sleep quality. These two factors (health concerns and anxiety) are part of the regression model, revealing that an increase in hypochondria and anxiety scores significantly increases the probability of being a bad sleeper, that is to say, of having a poor sleep quality. This explicative model presents a good predictive capacity which allows us to correctly classify 68.50% of the sample. We can correctly predict 78.30% of the good sleepers and 53.90% ofthe bad sleepers (scores higher than 5 on the Pittsburg global index), which grants the model an adequate specificity and sensibility. It is, however, necessary to consider that data used for the estimation respond to a range of restricted scores, causing any effect to be much less important than if we had worked with a more heterogeneous group of subjects. For example, global sleep quality scores can oscillate between 0 and 21, but in our sample they are comprised between 0 and 15. It is possible that, in including subjects who present high scores on the scales used in this study, a greater number of significant sleep quality predictors with greater magnitudes would be emphasized. Nevertheless, our interest resides in exploring the relationship between health concerns, anxiety and depression levels, and sleep quality in a non-clinical sample. So far, this relationship has not been explored in depth. One common limitation of these non-randomized studies is the difficulty to generalize findings to the normal population. Nevertheless, we assume higher possibilities to generalize findings if our study results are similar to those obtained from other non-clinical samples. In conclusion, health concerns and anxiety levels are the psychopathological traits most related to sleep quality and which hold a certain capacity to determine this quality in a sample of normal subjects. Both variables are clearly related to insomnia, as has been revealed in many insomnia patient studies. Therefore, we can verify that the pattern followed in the relationship between psychopathological traits and sleep quality in a non-clinical sample is similar to that found in sleep disorder patient samples, supporting that relationship between psychopathological traits and sleep quality in normal subjects opposite to patients with dream disorders can be drawn more easily from a quantitative than a qualitative approach. <![CDATA[Mecanismos de tolerancia analgésica a los opioides]]> resumen está disponible en el texto completo<hr/>Abstract: Opioid agonists medíate their analgesic effects by interacting with Gi/o protein-coupled receptors. Acute opioid administration produces: a) an inhibition of the adenylate cyclase (AC) pathway; b) an activation of G-coupled inwardly rectifying potassium channels (GIRKs); and c) a blockade of voltage-dependent calcium channels. All these effects result in cell hyperpolarization and neurodepression. In addition, opioids can stimulate the hydrolysis of phosphatidylinositol by activation of phospolipase C with the resulting calcium release from intracellular storages. However, this is a short-lasting excitatory effect. The development of analgesic tolerance to opioids after repeated administration is an undesirable side effect in clinical practice that limits their use for prolonged treatments. This paper reviews the main mechanisms that have been proposed to play a role in the development of opioid-induced analgesic tolerance, as well as the drugs that have some efficacy in reducing or preventing it. Tolerance is a complex process involving several neurotransmitter systems and neural adaptations occurring at different levels. It does not seem to be due to metabolic changes because concentrations of the main morphine metabolites, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G), are not significantly changed in tolerant patients. There is sound evidence suggesting that the main changes underlying tolerance development are pharmacodynamic in nature. These changes occur at: a) the receptor level; b) the second messenger level; and c) other neurotransmitter systems. At the receptor level, three different processes have been described: 1. phosphorilation-mediated desensitization; 2. (3-arrestin-dependent endocytosis; and 3. receptor down regulation. These processes can affect opioid receptors themselves (homologous changes) and/ or receptors to other neurotransmitters (heterologous changes). Different researchers have pointed out that there are some inconsistencies between the level of agonist-induced receptor endocytosis and the degree of analgesic tolerance produced by opioid agonists. For example, morphine does not promote efficient receptor internalization, but it produces a strong intracellular signal and, after repeated administrations, a high degree of tolerance. The opposite occurs with other opioids such as DAMGO, methadone and some 5-agonists; i.e., they produce low tolerance, but a high degree of receptor endocytosis. This fact has led to the development of a new theory which proposes that opioid-induced compensatory intracellular changes play an important role in tolerance development. These compensatory changes are more difficult to reverse than changes occurring at the receptor level, because receptor sequestration does not necessarily commit receptors to degradation, but lead, at least in part, to dephosphorilation and receptor recycling to the cell surface. Based on this, Whistler and coworkers proposed the "RAVE" (Relative Agonist signaling Versus Endocytosis) theory, stating that strong internalization would limit tolerance while sustained signaling would favor it. Probably the best studied change in intracellular signaling produced by chronic opioid administration is cAMP up-regulation. Acutely, this pathway is inhibited by opioids, but chronic exposure leads to a loss of inhibition of adenylate cyclase. This is due, in part, to a loss of the ability of the agonist-occupied receptor to activate Gi/o proteins and to an increased expression of certain types of adenylate cyclase, protein kinase A (PKA) and cAMP response element binding protein (CREB). Persistent opioid receptor activation also induces an increase in calcium channel activity, a decrease in the activation of G-coupled inwardly rectifying potassium channels (GIRKs), and a stimulation of the phospholipids signal transduction pathways. All these mechanisms have also been proposed to play a role in tolerance development. Several enzymes can be activated as a result of chronic opioid administration. Among them, phospholipase A2 (PLA2), cyclooxygenase (COX), in particular the COX-2 isoform, and nitric oxide synthase (NOS) are particularly relevant because their activation leads to an increase in prostaglandins and nitric oxide synthesis. Besides, repeated opioid agonist exposure induces an up-regulation of the cAMP-dependent protein kinase (PKA), the calcium-dependent protein kinase (PKC), the calcium calmodulin II dependent kinase and those kinases activated by mitogens (MAPKs). Phosphorylation by these kinases alters the functioning of many different target proteins, including NMDA receptors. When these glutamatergic receptors are phosphorylated, the Mg2+ block is removed and sodium and calcium ions can enter the cell. There is sound evidence indicating that NMDA receptor activation plays an important role in opioid analgesic tolerance because NMDA receptor antagonists prevent and/or delay its development in humans and animals. There is agreement in considering opioid analgesic tolerance as a complex phenomenon, but those changes resulting in an intracellular calcium increase seem to play a particularly relevant role. Since activation of certain physiological systems may antagonize some acute opioid effects, several investigators have proposed that, as a consequence of chronic opioid administration, endogenous antiopioid peptides are released to maintain the homeostasis. Among them, the best studied peptides are the Tyr-MIF-1 family of peptides, cholecystokinin (CCK), neuropeptide FF (NPFF) and orphanin FQ/nociceptin. Under physiological conditions these systems modulate opioid peptides, but the ba lance can be lost as a result of chronic opioid exposure. It has also been proposed that chronic opioid administration results in the activation of facilitatory pain descending pathways and that several neurotransmitter systems other than the adrenergic, serotonergic and opioidergic are affected by repeated morphine administration. Their relative impact in analgesic tolerance depends upon the species, the drug and the schedule of opioid administration. In preclinical studies, several drugs capable of preventing, decreasing or delaying analgesic tolerance when co-administered with opioids, have been identified. Based on this, several pharmacological strategies have been proposed to reduce tolerance. The following can be mentioned: a) administration of competitive and non-competitive NMDA receptor antagonists; b) co-administration of therapeutic opioid agonist doses with very low opioid antagonist doses; c) use of PKC inhibitors and COX inhibitors (in particular those with higher affinity for COX2 isoform); and d) co-administration of u. agonists with other agonists to induce receptor endocytosis thus preventing the induction of more long-lasting intracellular signaling changes. Among the pshysiological approaches, the proper dosification and administration schedule of opioids are crucial factors to prevent an artificial need of dose escalation. <![CDATA[Evaluación del componente afectivo de la depresión: análisis factorial del ST/DEP revisado]]> resumen está disponible en el texto completo<hr/>Abstract: Depression is a main Public Health problem due to its high prevalence and to the costs for intervention and treatment. Therefore, it is necessary to identify strategies that allow an adequate assessment that would let us obtain a more precise and useful diagnosis. Nevertheless, animportant obstacle for this task, is a lack of theoretical clarity in regard to diagnostic criteria or, especially, to symptoms which are relevant for depression. This fact is obvious in the scales focused on depression assessment, which have a broad variety of symptoms to assess, and it is possible to overestimate some areas or to underestimate others, related to theoretical criterions which were involved in test construction. So, depression is evaluated in accordance with the questionnaire that is used and, of course, depending of theoretical framework that supports this tool. Therefore, depression is defined in line with the criteria which evaluates it, with regard to assessment s criteria, which could explain the usual difficulty to identify common symptoms when some tools are used, which are then identified as genuine symptoms of depression. As the aim of this paper is to improve some of this limitations, the State/Trait Depression Questionnaire (ST/DEP) is showed as an useful tool for clinical and research work. It offers an assessment of one of the component of depression, the affective one, providing two measures: State and Trait. This allows to differentiate between intensity and frequency. Main-axis factor analysis has been made and the results have shown two main factors in affectivity: Dysthymia (negative affection) and Euthymia (positive affection). The interest on positive affection assessment aims to obtain a more precise tool. So, when scores are inverted in positive items, it is possible to obtain a measurement of low levels on affectation. The relevance of this fact is emphasized because it has been neglected in most of depression scales, that only identify presence or absence, a fact that limits the ability to estimate slight modifications. This issue is very useful at two levels: clinic and research. At a clinical level because it permits to identify slight changes in affectation, which could be important as measurement oftherapeutic efficacyand ofsymptoms remission. In research, because it offers the possibility to dispose of one able tool to differenciate of low levels of affectation, which allow a more accurate estimation of the depression symptoms, specially when working with a nonclinical population. The present study was carried out with a sample of 300 participants (103 males and 197 females), with mean age of 21.82 (2.74 s.d.) for males and 22.26 (3.66 s.d.) for females. It was an instrumental study where the Spanish Experimental Version of Stat-Trait Depression (ST/DEP) was used. All participants received information about research and they answered the questionnaires voluntarily. The findings are shown separately for the two scales (State and Trait) and for the two sub-scales (Dysthymia and Euthymia). Data indicated significant differences between males and females, being the highest scores for females. This is an evidence related to the higher prevalence of depression in women. It is very important to remark that essentially the same strong state and trait factors were found for both males and females, according to the factor structure of the Spanish Experimental Version of the State-Trait Depression Questionnaire (ST/DEP). These factors explained the 54% variance for females and of 53% for males. The Promax Rotation differentiated two factors clearly: Dysthimia and Euthymia. That was similar to what was found in the original English form of the ST-DEP. The factorial structure was then confirmed, because of the bifactorial structure which differentiated the negative and positive affectivity of Depression. Another positive result was the test ability to detect slight changes on affectivity, which will be useful to differentiate between clinical and non clinical population. It is important to point out that the ST/DEP is a measurement of one component of depression: affectivity, which has been identified as a relevant component in this disorder, but this tool is not enough to diagnose depression. This fact is relevant, because some tools for depression assessment are used as a diagnostic criteria, a fact that increases confusion in making a differential diagnostic between anxiety and depression or some other symptoms and clinical problems. All this results provide evidences of the psychometric properties of the Spanish ST-DEP, and make this scale a fruitful and useful assessment instrument. <![CDATA[Confiabilidad y validez de la SCL-90 en la evaluación de psicopatología en mujeres]]> resumen está disponible en el texto completo<hr/>Abstract: Women are especially vulnerable to anxiety and depressive disorders, as shown in the international literature and, in our country, in the National Survey of Psychiatric Epidemiology. However, it is important not only to identify the disorders as such, but also to identify the symptoms, that though not becoming a disorder generate illnesses in women and can respond to psychopharmacological or psychotherapeutic interventions. The Symptom Check List (SCL 90) is a widely used instrument. In this study, three groups of women were assessed: one group of the community (as reference group), a second one, of women diagnosed as depressed in a third level psychiatric institution, and another group of women with a temporomandibular disorder (TMD). The main objective of this study was to identify the psychometric characteristics of the SCL-90. The alpha of Cronbach was determined (internal consistency) by each one of the 9 subscales. The validity was determined through the following criteria: Validity of the SCL-90 as a method to detect depressed women. A ROC curve was made, comparing the depressed women and the women of the community. Validity of the SCL-90 as a measurement of depression. We hypothesized a high correlation with Beck's depression scale and Hamilton's depression scale. Sensitivity to change: effect size. We hypothesized that the greater effect would be in the depression subscale. For construct validity we compare the psychopathological profiles of the three groups of women. We hypothesized the existence of a gradient: the highest ratings in depressed women, the lowest in women of the community, and intermediate ratings in women with TMD. A factorial analysis was also carried out. Women older than 18 years of age were included, who were literate and accepted to participate in this study. They had no cognitive deficit (mental retardation, dementia, psychosis, states of confusion) or any other problem that would impede that they answer the surveys. The three groups were made up as follows: Women with TMD: Women with clinical diagnosis of Temporomandibular Disorder who went to an ambulatory service of Maxilofacial Surgery of the ISSSTEP (Social Security Hospi tal for State Government Employees), who had not had treatment for TMD during the past six months and who did not have degenerative arthritic illness. No previous psychiatric diagnosis. Depressed women: Women attending to the National Psychiatric Institute who were diagnosed with Major Depressive Disorder and were prescribed anti-depressive treatment. Women of the community: Mothers of the students at the secondary school Pablo Cassals, a field of work of the Community Psychiatric Service of the Psychiatric Hospital Fray Bernardino Alvarez Results: The interview was carried out with 289 women, 131 were depressed women, 96, women of the community, and 62, women with TMD. The mean (standard deviation) age was simi lar in the three groups: 36 (10), 37.7 (5.5), 37.6 (11.9) respectively Of the women with depression, 64% had a stable partner, 100% of the women in the community, and 61% of the women with TMD. 69% of the women with depression were dedicated to keeping house, 34% of the women with TMD, and 74% of the women of the community. Internal consistency was determined through Cronbach's alfa. The results of this analysis show us a high consistency of the instrument's nine subscales. Except for the subscale of paranoid symptoms in the women of the community, the alpha coefficients of all subscales in the 3 groups were higher than 0.7. Another form of establishing the validity of the instrument is through the determination of the cut-off point for patient identification. Through the ROC curve, 1.5 points in the subscale of depression was taken, as the best score to minimize the number of false positive and false negative results. As a measurement of depression, it was observed that the correlations of the subscales with Hamilton's depression scale and Beck's depression inventory had the highest correlations with the subscale of depression. The correlations with Beck's Inventory are higher than with Hamilton's scale of depression. This information supports the convergent validity of the subscale of depression with conventional instruments for its assessment. Another way of determining the validity of an instrument is to establish sensitivity to change. The size of the effect was calculated dividing the average of the difference (before-after) over the basal standard deviation of depressed women who participated in the longitudinal study. The size of the effect was higher in Hamilton's scale of depression and second in the subscale of depression, which indicates that there is a specific answer to a specific anti-depressive intervention. According to what has been hypothesized (construct validity), the highest ratings corresponded to the depressed women; the lowest to the women of the community, and the intermediate to the women with TMD. The differences between groups were statistically significant in each of the nine subscales and in the total indexes. The group of the community was significantly different from those of the depressed women and the women with TMD. The difference between these last two groups was also significant. In an exploratory factorial analysis of the 90 reactives, 87 had factorial loads higher than .40 in a first factor that explained 46.77% of the total variance of the SCL 90. Although 13 more factors with Eigen values higher than 1 were identified, the variance explained by each of them was lower than 5%; according to this technique, only one general factor is the best explanation for the checklist. The two reactives with small factorial loads were: "Do you believe that others should be blamed for your problems?", "Do you hear voices that others don't hear?" and "Excesive eating". Although the checklist was developed for the assessment of a psychopathological profile, some authors have proposed that it should be used as a measurement of general psychopathology. In this study, the checklist was evaluated as a method of assessing a psychopathological profile as originally proposed by Derogatis, as a method of assessing general psychopathology (with the three total indicators), and as a specific method of assessing depression. The information that most solidly supports the validity of the List's subscales is the differences in the profile that were observed among the three groups. The points in all the subscales were higher for women with TMD than those for the women of the community, but lower than in depressed patients; this shows that the psychological state of women with TMD tends to be similar to that of women with psychiatric diagnosis of depression. In this regard, the advantage of using the List to measure a profile is evident, and not only to assess general psychopathology The Symptom Checklist proved to have the psychometric characteristics appropriate to be used as an instrument to assess a psychopathological profile, to identify patients with depression, and to measure the intensity of depression. As an instrument to measure change, it is sensitive to psychopharmacological interventions. Although the size of the effect observed in the depression subscale is lower than that observed with the Hamilton scale, it is notably higher than the one observed with Beck's Depression Inventory. With these psychometric characteristics, it is possible to use the List in any type of research, including those that assess anti-depressive interventions. <![CDATA[Tendencias del uso de drogas en la Ciudad de México (1986-2003). Sistema de reporte de información sobre drogas]]> resumen está disponible en el texto completo<hr/>Abstract: Introduction: Currently, there are a number of methodological alternatives to find out the dynamics, the extension and the levels of drug use in the general population. The trends on drug use in our country llave registered important variations in the last 25 years. Among the most outstanding of these trends are: the high and stable use of marijuana, the increase in cocaine use and a decrease in the use of inhalants. Recently an increase in the use of these stimulants has been registered. The different studies show that these trends present some variations, since different group populations with different characteristics have been studied. This is the case of the data obtained by the Drug Information Reporting System -IRSD-which detects users with specific characteristics (regular drug users and advanced cases of addiction). Based on the facts mentioned above, the intention of this article is to present the main trends on drug use in Mexico City within the period between 1986 and 2003, according to the drug Information reporting System -DIRS- and to analyze these trends compared to other studies with different types of population. Background: The Information Reporting System on Drugs IRSD is a mechanism used to obtain data coming from diverse agencies that are related to the problem of the use of drugs; such agencies belong to the health sector or to the agencies of law enforcement. The main advantages of this type of systems are a low cost of operation -since it works with the infrastructure of the institutions that mainly conform the system- its easy application and that it provides current and fast information on the phenomenon. The continuous operation of the IRSD allows the accumulation of data with a sequence which makes possible the analysis of the trends on drug use, the identification of new groups at high risk and new drugs in the market. It also allows to identify the design of the preventive actions derived from the continuous analysis of information coming from its data bases. Mexico City has its own Drug Information Reporting System -IRSD- since 1986 coordinated by the National Institute of Psychiatry Ramon de la Fuente. Its objective is to count on a periodic and homogenous source of information which can be used as a diagnosis tool to design suitable programs of prevention appropriate to the Mexican population from a health perspective. The IRSD carries out semester evaluations of the phenomenon and has done now a total of 34. Method: Sample description: IRSD information between 1986 and June 2003 was used. This data base is conformed by 16,377 studied cases. It is a considered as «case» any person who recognizes to have consumed at least once in life some drug with the deliberate purpose of being intoxicated. The cases are also excluded from accidental or occupational exhibition and when only alcohol and tobacco have been consumed. Instrument: The Information is obtained from an individual scale applied twice a year, in health and justice agencies. This schedule collects information on the following aspects: socio-demographic profiles of the users, the reason for entering the institution, problems associated with the drug use and patterns of consumption of 12 drugs. For this article, only the information corresponding to the pattern of consumption was used to identify the trends. The analysis includes the information compiled by the IRSD during the period of 1986 and the first semester of 2003. Procedure: The instrument is applied twice a year, in periods of 30 days, during the months of June and November to any one who uses drugs and has entered the health and justice agencies for such reason. Once the period of information gathering is over, the applied instruments are sent by all the participant institutions to the National Institute of Psychiatry for their processing and analysis. Finally, the results are reintegrated into a report which is distributed among the participant institutions and people interested in this problem. Results: The analysis of the trends on drug use observed by the IRSD during the period 1986-2003 shows the following: Marijuana and inhalants reach the level of higher consumption for all drugs until the second semester of 1997. In the following years there is a decrease for these substances, particularly for inhalants. The trend of cocaine use shows significant changes. The first important increase in the levels of use was observed between the years of 1993 and 1997. At the end of this period the use of cocaine was reported by every 40 of 100 users. The following year this proportion went up to 63, which represents an increase of more than 50 per cent. From this year and up to date the trend shows a stable behavior with similar levels of use. In regard to hallucinogens low levels of consumption have been observed, during the 15 years of evaluation by the IRSD. Approximately five of 100 cases report their use by semester. Sedatives and tranquilizers show the highest increase during the first semester of 1993, with 28 users for every 100 cases; since then a decrease in consumption has been observed. The consumption of stimulants has presented a very irregular trend through the evaluations. For heroin use a very low percentage of consumption is observed with one out of every 100 cases. There was a slight increase only in two evaluations during the first semester of 1992 and 1993. Conclusions: The most outstanding results regarding the tendencies of consumption of addictive substances is the increase of cocaine use at the beginning of the nineties and has always showed a tendency do increase. In the last evaluation certain stability in its consumption, is observed, at least in the last two years. It is important to emphasize that the increase in the consumption of cocaine may probably be associated to its availability in Mexico as well as that for its derivatives. Equally significant within this period of evaluation is the decrease of inhalant consumption, specially during 1999. Some studies show a possible substitution of these substances by cocaine and or its derivatives. The trends of drug use provided by the IRSD must be interpreted taking into account that the drug user population included in the evaluations belongs to a sector that does not represent the whole universe of users in the general population. However the trends of drug use reported by the IRSD are in agreement with those reported by the surveys in general and school population, where marijuana, cocaine and inhalants were reported as the drugs of greater use among the Mexican population. It is important to note that when the lack of financial and or human resources become real obstacles to carry out sophisticated, extensive periodic studies to evaluate drug use, a system of this type is a valuable alternative for the developing countries. <![CDATA[Tendencias de la conducta antisocial en estudiantes del Distrito Federal: mediciones 1997-2003]]> resumen está disponible en el texto completo<hr/>Abstract: Introduction. This paper analyses the evolution of antisocial behavior within the context of representative cross-sectional studies in student population from Mexico City. Surveys with students have collected data about substance use and related factors. The latter is associated with antisocial behavior and delinquency eating disorders, risk sexual behavior, and suicide attempt. Statistics on younger offenders show an increased number of subjects presented before law institutions, meaning that they have been prosecuted somehow (there were 2623 cases in 1999, and 3506 in 2003). At the same time, there is a decrease in the age for committing these faults which are becoming more serious; a larger number of homicides, raping, and carrying weapons have been reported. The objective of this paper is to present tendencies of antisocial behavior through data obtained from three different representative surveys in junior high school and high school students from Mexico City (1997, 2000, and 2003). Surveys were held by the Instituto Nacional de Psiquiatría Ramón de la Fuente and by the Secretaría de Educación Pública. Method. The analysis unit considered for this study was the student himself coming from state and private schools. Three levels were studied: junior high school, high school, and technical schools. Sample design was planned based on the evaluation of drug use tendencies in the students from this population, determining the level of contribution of each district in the city. Schools were randomly selected in each of the 16 districts. Sample design was stratified, two-staged, and in clusters. Stratification variable was the level of the school. First selection unit was the school, and second was the school group. Sample was self-weighted using the city district as the weigh variable. Three probabilistic samples were obtained, representing each one of the districts and education level: 1997 sample, N=10173; 2000 sample, N = 10578; 2003 sample, N=10659. Outcome rate in each measure was 97% in 1997, 95% in 2000, and 98% in 2003. Age mean in the three samples was 14.6 years old, and equivalence men-women was similar in the three studies. Questionnaire used has been validated before, and its basic indicators have maintained consistency through different researches. Socioeconomic and antisocial behavior data were used for this study. Two factors previously obtained were used. The first one was called Violence and Thieving Behaviors, this one includes picking things worth 50 pesos or less, taking things from a store without paying for them, damaging other people's property, punching or hurting someone, being involved in fights, and using firing objects. The second factor was called Serious Antisocial Behaviors, and it included: picking things worth 500 pesos ormore, breaking locks, attacking someone using an object or weapon, selling drugs, and using a knife or gun to rob someone. These factors have been already used and have shown good consistency. The survey operative design included a main coordinator, supervisors, and pollsters who were trained on conceptual issues about addiction, project background and objectives, instrument use, instructions for interviewing, and group selection. Emphasis was made on proper instructions for subjects, as well as remarks for anonymity and confidentiality in handling information. Inconsistent questionnaires were corrected or eliminated. Intelligent software was used for registering data, which verified that the answers were coherent. Results. There was a 2% increase in antisocial behaviors among students between 1997 and 2000; the most notorious raise was observed in behaviors from factor Violence and Thieving, which fluctuated between .57% and 1.8%. From 2000 to 2003 there was a raise of 6.7% for any antisocial behavior, and the increase was again more notorious in Violence and Thieving (6.5%). There were minor increases in the second factor, though these were important. For instance, picking things worth 500 pesos or more, and attacking someone had a bigger raise in 2000 and 2003, while breaking locks had its bigger raise between 1997 and 2000. No changes were observed for selling drugs and using a knife or gun to rob someone. There was a 2.47% increase for any antisocial behavior in men between 1997 and 2000, basically in the factor Violence and Thieving. From 2000 to 2003 this increase raised to 7.36%, observed again in the Violence and Thieving factor. In the case of women, there was only an increase in two behaviors between 1997 and 2000: picking things for 50 pesos or less and breaking locks. From 2000 to 2003 there was an important increase in behaviors pertaining to Violence and Thieving (5.71%), to be involved in fights had the highest increase. Between 2000 and 2003, women participated in more serious acts. The proportion of students behaving antisocially was calculated considering the districts. The district of Tlalpan had the only increase observed between 1997 and 2000. Significant raise was observed in almost every district (except for Cuajimalpa and Gustavo A. Madero) from 2000 to 2003. Venustiano Carranza, Benito Juarez, Iztacalco, and Alvaro Obregon had the biggest increase. Variations are the same for both factors. Discussion. This study allows to see the changes in antisocial behavior rates in Mexico City students from 1997 to 2003. Slight variations were found in some behaviors between 1997 and 2000, there were no modifications in others. However, there was an important raise from 2000 to 2003, which is bigger if compared to 1997. Increase in antisocial behavior is similar for men and women, although proportion is unequal yet; almost two men for every woman. When considering district as a control variable, Benito Juarez and Tlalpan show the higher prevalences on any antisocial behavior. This situation is similar for Violence and Thieving. In the case of Serious Antisocial Behaviors, Venustiano Carranza and Azcapotzalco had the higher prevalences. It is important to fully understand the reasons of adolescents for behaving antisocially. Apparently the conditions facilitating this type of behaviors are not only related to marginalization and social disadvantage, but to others, such as new interaction ways, which favor the search for exciting sensations and hiding from supervision. This includes involvement in risk behaviors, such as unsafe sexual intercourse, drug use, violence, and burgling. It is necessary to go deeper into these new forms of antisocial behavior and to work more in prevention as an attempt to counteract present tendencies of this issue. <![CDATA[Panorama del trabajo de investigación en epidemiología psiquiátrica en México: últimos 30 años]]> resumen está disponible en el texto completo<hr/>Abstract: Mental health frames and policies to enforce them cannot be excluded from the social context, neither the population's health conditions or the international tendencies. Their strategic place depends on the role they play in the global milieu, and on the benefits derived from what is done in terms of prevention and attention within the field. Psychiatric epidemiology serves as a tool for knowing mental disorders distribution, the risk factors implied in their etiology and evolution, as well as the elements influencing their detection and treatment. But psychiatric epidemiology has remained behind other branches of epidemiology given the problems for conceptualizing and measuring mental disorders. Thus, most of the work has been basically descriptive. Nevertheless it has been possible to move forward through historical series, analyses of community diagnosis, health services evaluation, risk measurement, description of clinical frames, identification of new syndromes and its related causes, and in carrying out national and international representative surveys in general population. This paper has four objectives: 1. to present an overview of the work done in epidemiologic psychiatry in Mexico for the last 30 years; 2. to analyze the main areas explored; 3. to identify the most used designs; and 4. to enumerate the populations studied. Method. Articles about different aspects related to study and analysis of psychiatric epidemiology in Mexico were collected, including those reporting empirical results. The search was performed in a bibliographic database consulted in the Centro de Información en Salud Mental y Adicciones (CISMAD), located at the Instituto Nacional de Psiquiatría Ramón de la Fuente. Approximately 158 papers published in national and international journals were reviewed. Results. In the 1970's, work was aimed towards historical analysis seeking to provide an epidemiologic view of psychiatric disorders in Mexico. Interest was set on aspects related to attention of mental patients, the teaching of psychiatry, and in the advance of psychiatric knowledge. Some studies were done to have a look at the frequency and characteristics ofcertain diseases in unexplored populations. During the 1980's there was a renewed interest in dissecting the status of epidemiologic psychiatry and mental health, together with an intention to state its role in the future. Cross sectional studies were performed to know the prevalence ofdifferent mental illnesses in medical care. Validity and reliability of several detection and diagnosis instruments were evaluated, and some essays about the importance of having a clear view of attention needs and demands were carried out. At the beginning of the 1990's there were descriptive studies in rural and urban populations to describe the main elements determining the use of health services and the quest patterns for different attention options. New diagnosis instruments were used in subjects attending the first and second levels of care. Research on schizophrenia began with reviews and dissertations about its status in Mexico and other countries. Results of the Mental Health National Survey showing prevalence in general population were made public. Home base surveys made possible to know the scope of mental illness in children, adolescents, and adults. The use of epidemiology in child psychiatry allowed the inclusion of developmental psychopathology in the analysis of the interaction and interdependence of biological, psychological, and social variables. The 21st century set the emergence of the first longitudinal reports on suicide. Work continues on the prevalence of mental illness and new approaches on risk factors are added. Research on the frequency of disorders from well-defined diagnosis criteria is signed. Use and abuse of substances, and violence against women are studied to know their effects on mental health. The Survey on Psychiatric Morbidity was planned and conducted with great methodological rigor, and thus it was included in the first generation of ICPE studies, which has enabled data comparison on an international basis. Results have shown that depressive disorders are the most recurrent, whereas disorders related to substance abuse and dependence affect basically men, and that anxiety disorders are the most chronic. In 2000, the World Health Organization launched an initiative to make national epidemiologic studies in different countries, and Mexico was the first Latin American country to participate. The National Psychiatric Epidemiology Survey initial results have confirmed that the prevalence of disorders along life is 28.6%, and that annual prevalence is 14%. Discussion. It is important to underline the need to pay attention to mental health problems from a preventive approach. In this respect, Mexico is a little behind and it is urgent to grow according to the advances, instruments, and techniques used in other countries. It is also important to acknowledge the work done so far; in this sense, the development of national surveys accounts for it. General population studies allow for the generation of an overview of the needs and the basic issues to create preventive interventions. Mexican epidemiologic psychiatry is in a developmental stage, stressed by the use of standardized diagnosis criteria to get comparable data (both from Mexico and other countries in the world). However, the study designs employed until now do not allow for the exploration of the temporary evolution of disorders and related factors to be more exhaustive. Besides, there are limitations in evaluating health services, which could be overcome through cost-effectiveness analyses. In the national context it is notorious the lack of inquiring about the diagnosis boundaries, which should be one of the main directions of psychiatric epidemiology in the next years. This would be highly relevant taking into account that Mexico is a transition country that accepts and uses both European and American criteria. It should be mentioned also that, although Mexico has the same kind of problems than other countries, research has shown they are smaller, which makes studies on protective and risk factors a priority for the future. There are still certain aspects of epidemiology which remain practically untouched in research. For instance, it is important to focus on rural areas, on migrant populations, and on native groups to overcome the existing backwardness. Another important topic in the prevention area is the work to do carried out with mental problems during childhood and adolescence. Longitudinal studies would mark the path to evaluate different types of factors: genetic, biologic, familiar, psychodyna-mic, social, and economic. It is also important to analyze the interaction among them to know its impact on etiology and on the development of psychopathology during life. <![CDATA[La plaqueta como marcador biológico periférico de la función serotoninérgica neuronal]]> resumen está disponible en el texto completo<hr/>Abstract: Among all neurotransmitters, serotonin or 5-hydroxi-triptamine (5-HT) is probably the most studied in neuropsychopharmacology. Interest in this neurotransmitter is due to cumulative evidences showing that neuronal serotonergic systems are altered in depressed patients, as well as in several behavior dysfunctions like aggressiveness, impulsiveness, and suicide attempts, among others. Also, specific agonists and antagonists have been synthesized, which has enabled the characterization of the serotonergic receptor subtypes. Furthermore, highly selective inhibitors ofserotonin uptake have been developed, and these are capable of working in the synaptic terminals, as well as in other cell systems, such as platelets. This has allowed for the understanding and characterization of the action mechanisms of diverse psychoactive drugs interacting with the serotonergic system. Platelets have been proposed as an outlying model resembling that of serotonergic neurons due to the similarities they present in the uptake, storage, and serotonin release mechanisms, as well as the presence in platelet membranes of serotonin 5-HT2A receptors. The platelets have a serotonergic system consisting of four main components: 1. an uptake mechanism, 2. intracellular storage organelles, 3. serotonergic receptors in the plasmatic membrane, and 4. a mitochondrial enzyme, the monoamine oxidase (MAO), which metabolizes serotonin. All these elements show physiologic similarities with the neuronal serotonergic system. Serotonergic similarities in neurons and platelets In the Central Nervous System (SNC) serotonin acts mainly as an inhibitory neurotransmitter. The precursor for its synthesis is the aminoacid tryptophan. This is taken from the blood to the cerebral interstice, where it is taken up by the nervous terminals and converted into 5-hidroxytryptophan (5-HTP) by the enzyme tryptophan hydroxilase. The conversion to 5-HTP is a key regulatory step in serotonin synthesis, and is converted quickly in 5-HT by the action of the aromatic L-acid descarboxilase. However, platelets do not synthesize 5-HT, since they do not possess tryptophan hydroxilase. Thus they only display uptake, storage, and serotonin release functions. Serotonin actions The neurotransmitter functions of neuronal serotonin, generally inhibitory, depend on the serotonergic receptor characteristics it interacts with. Its action mechanism can be mediated through second messengers (metabotrophic receptors) or through a direct action over ionic channels (ionotrophic receptors). In the platelets, serotonin is stored in a slow replacement depot, where it can be released from by exocythotic mechanisms. Serotonin participates in the platelet activation that allows for their aggregation to each other for blood clotting process. Serotonin uptake To stop the serotonin neurotransmitter function, neuronal serotonin is taken up from the synaptic cleft by transporter proteins. The serotonin neuronal uptake is impelled by a proton gradient that requires ATP. The 5-HT uptake can follow two paths: the 5-HT can be metabolized by the MAO into 5-hydroxy-indolacetic acid, or it can be reintroduced into release vesicles in order to be reutilized as a neurotransmitter. The serotonin uptake by platelets occurs either by passive diffusion or by active transport mechanisms. Under physiological conditions, the active uptake mechanism is the most effective. This uptake is mediated by proteins similar to the ones required for the neuronal serotonin uptake in the brain. It requires energy and the presence of Na+ and Cl-. The platelet uptake system has a relatively high affinity (Kd) for 5-HT, being similar in magnitude from platelets to neurons. The platelet storage of 5-HT is located mainly in the dense bodies and in the storage granules. Serotonin transporters in platelets and synaptic terminals The main form of ending a serotonergic transmission pulse is by taking up 5-HT molecules from the synaptic cleft directed to reduce the serotonin concentration, which then stops the serotonergic neurotransmission. The uptake process involves a molecular recognition of 5-HT by the transporter, its binding, and passing through the membrane to be released within the cellular. Serotonin molecules bound to its transporter protein cross through the membrane using Na+ as a driving force. The return ofthe transporter to its original position requires K+ as the driving force to step this protein toward its original position. When a selective serotonin reuptake inhibitor is administered, the 5-HT concentration increases in the synaptic cleft, which enhances serotonin neurotransmission. This increase induces a down regulation cascade of both: serotonin autoreceptors (presynaptic) and postsynaptic receptors, that may finally reestablish the resting state of the neuron. It has been confirmed that the protein for neuronal as well as platelet serotonin uptake transport are synthesized by the same gene. Experimental evidence has shown that the platelet transporter presents the same functional and pharmacological characteristics than the neuronal transporter. Serotonergicreceptors Seven types of pre and post synaptic serotonin receptors, which have also several subtypes, have been characterized. Pre and post synaptic 5-HT 1 receptors . The 5-HT1 receptors are involved in both pre and post synaptic serotonergic neurotransmission. The presynaptic 5-HT1A receptors are autoreceptors. Due to their localization in the cellular body and in the dendrites, they have been named somatodendritic autoreceptors, which control the serotonin release. The postsynaptic receptors may play a role in hypothalamic thermoregulation. The presynaptic 5-HT1D receptors are autoreceptors that perform a regulation by blocking the 5-HT release. These receptors are not synthesized in platelets. Postsynaptic 5-HT 2 receptors . The 5-HT2 receptor subtypes are 5-HT2A,BandC. When postsynaptic 5-HT2Areceptors are bound to serotonin, they drive the transduction of neuronal impulses through the production of second messengers within the postsynaptic neuron. These second messengers induce the synthesis of intracellular proteins denominated transcription factors, which may regulate the expression of several neuronal genes. Platelet 5-HT2A receptors correspond to the neuronal 5-HT2A metabothropic receptors and induce alterations in platelet density and affinity. 5-HT 3 receptors . These receptors were originally described in the periphery, specifically as part of the enteric nervous system. In the CNS 5-HT3 receptors are densely present in the solitary tract nucleus and in the area postrema. These receptors are the onlymonoaminergic receptors consistingofionic channels operated by aminergic neurotransmitters. The stimulation of 5-HT3 receptors is responsible of several secondary effects of the selective inhibitors of serotonin reuptake (SISR). These effects are not mediated only in the CNS, but also in sites outside the brain, such as the intestine, which possess this type of receptors also. These receptors are not located in the platelets. 5HT 4-7 serotonergic receptors . These receptors are distributed throughout the body, where they stimulate the alimentary tract secretions and facilitate peristaltic reflexes. Their localization in serotonergic areas in the brain and platelets has not been established. Notwhithstanding their limitations, the characteristics reviewed support the conclusion that platelets can be used as partial models to study the neuronal serotonin 5-HT2 binding and uptake functions. As Alfred Pletscher stated: "although the incomplete of the pattern demands care in its application, they could have the advantage of the relative simplicity".