Resumen:

Los objetivos del estudio son: 1) determinar la relación entre alexitimia y depresión; 2) observar la relación entre alexitimia, medida por la TAS-20, con las escalas de validación y clínicas del MMPI, especialmente en relación con la depresión y la somatización, centrando el análisis en las dimensiones subyacentes; y 3) establecer si la relación entre alexitimia y somatización es directa o si está mediada por la depresión. Se ha de señalar que todas las variables psicopatológicas de este estudio se toman como rasgos definidos según el MMPI y no se establecen con base en criterios diagnósticos.

La muestra constaba de 362 estudiantes y se obtuvo durante el proceso de selección de alumnos. La alexitimia se midió con la TAS-20 y las variables psicopatológicas con el MMPI. Los datos se analizaron por correlación lineal, correlación parcial y análisis factorial.

La escala de depresión del MMPI se correlacionó de forma directa (de .265 a .199) con la puntuación total de la TAS-20 y con sus dos primeros factores: dificultad para expresar sentimien tos (DES) y dificultad para identificar sentimientos (DIS); permaneció independiente del tercer factor de la TAS-20, pensamiento externamente orientado (PEO). En el estudio de las estructuras factoriales, la puntuación total de la TAS-20 y del DIS aparecieron asociadas con un estilo de escasa defensividad y baja deseabilidad social, aunque permanecieron independientes del factor de depresión e introversión social. El PEO se asoció con la manifestación de un rol de género instrumental y poco expresivo (masculino) y no mostró ninguna relación con la depresión. Sólo DES formó parte del factor de depresión e introversión social. Al contemplar simultáneamente los tres factores de la TAS-20 con las escalas del MMPI, DIS y DES se asociaron con un estilo no defensivo. El PEO se asoció con un rol de género masculino y baja suspicacia, permaneciendo las tres escalas de la TAS-20 independientes del componente factorial de depresión e introversión social.

La alexitimia se mantuvo independiente de la escala de Histeria; y se asocia muy débilmente con la de Hipocondriasis; presentando dificultad sólo para identificar los sentimientos, en relación directa con la hipocondría. La dimensión Somatomorfa de las escalas clínicas del MMPI se correlacionó de forma significativa, inversa, pero débil con PEO (-.200), TAS-20 (.154) y DES (-.135). Ninguna de estas correlaciones mostró enmascaramiento de la depresión. Cuando se eliminó el efecto de la depresión en la relación entre la alexitimia y la dimensión somatomorfa, ésta no disminuyó ni dejó de ser significativa, sino que surgió más clara. A su vez, cuando se eliminó el efecto de la dimensión somatomorfa sobre la relación entre alexitimia y depresión, tampoco ésta mermó, sino que también emergió más definida. Esto refleja una relación directa de la alexitimia tanto con la dimensión depresiva como con la dimensión somatomorfa; estas dos últimas dimensio nes se relacionan entre sí. La asociación de la alexitimia es más fuerte con la dimensión de depresión que con la dimensión somatomorfa. Con base en estos datos, la alexitimia no puede considerarse como un rasgo depresivo, y menos aún de depresión enmascarada o somatomorfa, al menos en la población general de estudiantes universitarios. La dirección de la asociación entre la alexitimia y la dimensión somatomorfa va contra las expectativas de la bibliografía temprana sobre alexitimia, bajo la cual se esperaría una asociación directa. Sin embargo, se obtuvo una correlación inversa. A más alexitimia, menos rasgos histriónicos, quejas de dolores imaginarios, preocupaciones hipocondríacas y somatizaciones, resultado concordante con otros estudios recien tes realizados en población clínica.

A partir de los resultados de este estudio, realizado en una muestra no clínica de 362 estudiantes universitarios, se puede afirmar que la alexitimia (medida por la TAS-20) y la depresión (medida por el MMPI) son dos variables que se correlacionan de una forma significativa, directa y moderadamente baja; resultan ser dos conceptos claramente distinguibles y no se puede reducir la alexitimia a un rasgo depresivo y menos aún de depresión enmascarada.

Palabras clave: Alexitimia; depresión; psicopatología; TAS-20; MMPI

Abstract:

The objectives of the present study are: 1) to determine the relationship between alexithymia and depression to contrast if they both are related, although distinguishable; 2) to observe the relationship between alexithymia, measured by the TAS-20 and with the validation and clinical scales of the MMPI, especially in connection with depression and somatization, centering the analysis in the underlying dimensions; and 3) to establish if the relationship between alexithymia and somatization is direct or mediated by depression (indirect). It should be pointed out that all the psychopathological variables of this study are considered as features and these are defined by the MMPI but not by diagnostic criteria.

The study sample was integrated by 362 students and obtained during the students' selection process of the UANL Psychology School. Alexithymia was measured by the TAS-20 and the psychopathological variables by the MMPI. The TAS-20 is a Likert scale of 20 elements, constituted by three orthogonal factors: difficulty in expressing feelings (DEF), difficulty in identifying feelings (DIF) and externally oriented thinking (EOT). Data was analyzed through the Pearson's lineal correlation technique, partial correlation and factor analysis. The factorial analysis was done by the method of principal components with an orthogonal rotation Varimax. The criterion of Kaiser-Meyer-Olkin (eigenvalues over one) was used to determine the number of factors.

It was hypothesized that: 1) The total score of the TAS-20 and their first two factors (DEF and DIF) would correlate positive and significantly with depression, and that both concepts would be perfectly distinguishable based on the factorial saturations of the scales inside the components that arise when factoring the TAS-20 and the MMPI clinical and validation scales. 2) A positive and significant correlation was expected between alexithymia and the somatoform dimension (in regard to the scales of Hysteria and Hypochondriasis). 3) If the relationship between alexithymia and the somatoform dimension was direct, then the correlation would be increased, in some degree, when eliminating the effect of depression; consequently, the correlation between alexithymia and depression would be increased when eliminating the influence of the somatoform dimension. On the contrary, if the relationship were indirect or if this reflected a masked or somatoform depression, then the correlation of alexithymia with the somatoform dimension would be weaker than with the depression. Besides, the correlation between alexithymia and somatoform dimension would be diminished or would not become significant if the effect of the depression was eliminated. Consequently, the correlation between alexithymia and depression would diminish if the influence of somatoform dimension was partialized.

The MMPI Scale 2 (depression) correlated in a direct, significant (p <.01) but in a low way (from .265 to .199), with the TAS-20 total score, and the first two factors (DEF and DIS), remained independent from externally oriented thinking (EOT).

In the study of the factorial structures, the TAS-20 total score and the difficulty identifying feelings (DIF) appeared associated to a defensive style of low defensiveness and social desirability, remaining both variables independent of the depression and so cial introversion factor. Externally oriented thinking (EOT) was associated to the manifestation of an instrumental and not very expressive (masculine) gender role, not showing any association with depression. Only difficulty expressing feelings (DEF) formed part of the depression and social introversion factor. When contemplating the three factors of the TAS-20 simultaneously with the MMPI Scales, difficulty identifying feelings and difficulty expressing feelings were associated to a style of low defensiveness; externally oriented thinking was associated to a masculine gender role and low suspiciousness, remaining the three scales of the TAS-20 independent of the depression and social introversion factorial component. This data justify to consider depression and alexithymia as related but perfectly distinguishable concepts.

Once the factorial structure of the MMPI clinical scales was estimated in our control sample of 362 students, three dimensions were observed: 1) Psychoticism characterized mainly by a very inadequate social behavior; 2) Depression and social introversion; and 3) Somatoform related with conversion symptoms, hypochondriac complaints or concerns and adoption of an expressive and not very instrumental (feminine) gender role. As it was expected, the strongest relationship was with the Depression dimension. This first MMPI clinical scale dimension was related both with the TAS-20 total score and its three factors (DEF, DIF and EOT), showing the higher magnitude correlation coefficients (from .351 to .129). In second place appears the psychoticism dimension. This second MMPI clinical scale dimension presented significant correlations both with the TAS-20 total score (.214) and with the difficulty identifying and expressing feelings (.239 with DIF and .173 with DEF). The somatoform dimension (conversion symptoms, hypochondriac complaints and feminine gender role) was the one that presented the weakest relationship with alexithymia. This third MMPI clinical scale dimension had more explanatory capacity in the third factor of the TAS-20 (-.200 with EOT) and a little less in the TAS-20 total scale (-.145) and its first factor (-.135 with DEF).

In our sample of 362 students, alexithymia remained independent of the MMPI scale 3 (Hysteria) (with regard to somatization and conversion symptoms) and was very weakly associated with MMPI Hypochondriasis scale. Only difficulty identifying feelings (DIF) presented a direct relationship with the Hypochondriasis Scale (.111). The Somatoform dimension of the MMPI clinical scales correlated in a significant, inverse, but weak way with EOT (-.200), the TAS-20 total score (.154) and DEF (-.135). None of these correlations showed masking of depression. When the influence of depression was eliminated in the relationship between alexithymia and somatoform dimension, this did not diminish or stopped being significant, but rather it became clearer. In turn, when the effect of the somatoform dimension was eliminated in the relationship between alexithymia and depression, this did not decrease, but emerged even more definite. This shows a direct relationship of alexithymia both with the depression dimension and the somatoform dimension, being these two latter dimensions related to each other. The association of alexithymia is stronger with the depression dimension than with the somatoform dimension. Based on the given data, alexithymia cannot be considered as a depressive feature neither as a form of masked somatoform depression, at least in general population.

The association between alexithymia and the somatoform dimension disagrees with the expectations of the early alexithymia literature. A direct association was expected. Nevertheless, an inverse correlation was obtained. The more definie the features of externally oriented thinking are, the higher the score in the TAS-20 is, or the more difficult it is to express feelings; the less conversion symptoms, hypochondriac complaints and feminine manifestation of the gender role will shown by the subjects. These results are in agreement with those of other recent studies that were done in clinical population.

The fact that both, the TAS20 total punctuation and the difficulty identifying feelings, in the factorial analyses, conform a dimension of defensive style with affective isolation and negation of conflicts and problems, gives more support to this result.

From the results of this study that was carried out in a 362 university students' non-clinic sample, one can affirm that alexithymia (measured by the TAS-20) and depression (measured by the MMPI) are two variables that are correlated in a significant, direct and moderately low way; being two clearly distinguishable concepts because of their form of grouping in the factorial analyses. Alexithymia is related especially with a defensive style of scarce defensiveness and low social desirability. Their relationship with the Somatoform dimension (in regard to conversion, hypochondriac complaints and adoption of an expressive and not very instrumental gender role) is significant, inverse, weak and very lightly attenuated by depression. The more alexithymic the subjects seem to be, the less conversion symptoms, somatization complaints, and hypochondria they will have, and they will show a more definitive masculinity in performing their gender role. In general, the results are consistent with the idea that alexithymia cannot be reduced to a depressive feature and even less to a feature of masked or somatoform depression, at least in non clinic university student population.

Key words: Alexithymia; depression; psychopathology; TAS-20; MMPI