[Affectivity and alexithymia: two dimensions explicative of the relationship between anxiety and depressive symptoms]

Objectives: The main objective of this study was to support the existence of emotional dimensions common to anxiety and depressive symptomatology, and confirm the common elements of emotional vulnerability, characterized by negative affectivity and alexithymia. The second objective of this study was the identification of characteristics specific to each disorder. We made three assumptions: there is a significant relationship between anxiety and depressive symptoms, exists on community processes between these two entities, objectified by the sub dimensions of negative affectivity and the difficulty in identifying emotions certain dimensions are specific to each disorder.

Method: The study participants were students from 1st to 4th year of the University of Provence. The sample consisted of 317 subjects (77% female and 23% male; mean age=20, 61 ± 1.55 years), who gave written informed consent and completed questionnaires collectively. We administered a protocol to the subjects consisting of three self-assessment scales to assess emotional dimensions and anxiety and depressive symptomatology. The dimensions of affectivity were assessed by the EPN-31. It consists of 31 items grouped into three factors: positive emotions, negative emotions and feelings of surprise. The emotional functioning was assessed by the scale of the Twenty-item Toronto Alexithymia Scale (TAS-20). It allows an overall assessment of the level of alexithymia, as well as three dimensions as represented by specific sub scales: difficulty identifying emotions (DIE), difficulty differentiating emotions (DDE), and externally oriented thinking (EOT). This scale is most used in the assessment of alexithymia. The anxiety and depressive symptoms were assessed by the subscale of anxiety and depression of the SCL90-R. This scale is widely used in screening for psychiatric symptoms, and has been validated internationally.

Statistical analysis: we performed descriptive analysis, correlational analysis (Bravais-Pearson's correlation) and hierarchical multiple regression using SPSS 15 software.

Results: The results validate our assumptions, showing that women are more anxious (M=6.68 ± 6.20 ; P=0.02) and more depressed (M=10.61 ± 8.73 ; P=0.01) than men (mean-anxiety=4.77 ± 4.97 ; mean-depression-6=7.75 ; 53). They also have more "difficulty" identifying feelings (M=17.92 ± 5.95, P=0.01) than men (m=15.65 ± 6.00). The analysis of relationships between the different variables shows the existence of several significant connections. Among them we find a strong positive correlation (r>.50 ; P=0.01) between anxiety and depression. Moreover, these two symptoms maintain strong relationships (r>.50; P=0.01) with negative affectivity, moderate and negative with positive affectivity (r>.30; P=0.01), and moderate and low with emotional activation (r>.10; P=0.01). There are also significant relationships between affective symptoms and emotional dimensions of alexithymia: difficulty identifying feelings (r>.40; P=0.01) and difficulty describing emotions (r>.20; P=0.01). Finally, the regression analysis shows, for the anxiety factor, which only contribute significantly following dimensions: gender, negative affectivity, emotional activation and the two sub dimensions of alexithymia "difficulty identifying feelings" and "externally oriented thoughts", which explain 43% of the variance in scores (R(2)=.43, P=0.0001). Depression shares with the following dimensions: gender, negative affectivity, difficulty in identifying emotions, and includes a specific dimension, positive affectivity. This model explains 51% of the variance (R(2)=. 51, P=0.0001). However, the lack of contribution of emotional activation and "externally oriented thoughts" must be emphasized.

Discussion: Our study reveals the existence of a "common nucleus of vulnerability" characterized by negative affectivity associated with difficulty identifying emotions. Specific dimensions nevertheless appear to exist, and depression is strongly explained by low positive affect (anhedonia dimension); anxiety associated specifically to emotional activation and finally thought outward, marking the size limitation. The imaginary life in alexithymia, appears to operate in depression, perhaps as a mechanism of emotional repression. The involvement of alexithymia in the functioning of the affective disorder is confirmed, this helps to clarify the modalities of therapeutic care that we offer.