Background: Personality and emotional factors are thought to influence the onset of psoriasis, the occurrence of relapses, and the sensitivity of this condition to dermatological treatments. Objective:To explore the relationships between emotional disorders and emotional information processing in the one hand, and psoriasis severity and response to treatment on the other. Methods: We recruited 93 patients through an article in the local press. These patients attended three consultations. We evaluated psoriasis severity by Psoriasis Area and Severity Index (PASI) score and response to treatment by change in PASI score from baseline to the 3-month visit. We screened for comorbid mental disorders, using the Mini International Neuropsychiatric Interview. We used the Hospital Anxiety and Depression Scale to assess anxiety and depressive symptoms. Alexithymia (difficulty in identifying and expressing emotions) was evaluated with the 26-item version of the Toronto Alexithymia Scale (TAS-26) and the ability to integrate and differentiate emotions (emotional awareness) was assessed with the Lane and Schwartz Levels of Emotional Awareness Scale (LEAS). Results: Forty patients presented at least one psychiatric diagnosis and 33 were considered alexithymic (TAS ≧73). No psychological score was associated with baseline PASI score, which was higher in men and positively correlated with disease duration. Patients who considered their disease to be stress-reactive tended to have lower LEAS scores (p = 0.052). At the 3-month visit, PASI scores had significantly improved in the subset of patients (n = 67) presenting severe psoriasis at inclusion (PASI >2); emotional awareness and anxiety scores had also improved in these patients (p < 0.001), but dermatological and psychological changes were not statistically related. Dermatological improvement at 3 months with respect to baseline PASI was predicted by longer disease duration (>20 years) and lower baseline LEAS score (p = 0.044 and p = 0.021, respectively). Conclusion: This study demonstrates the value of assessing the ability of patients with psoriasis to process emotional information, as defined by emotional awareness. Patients with low LEAS scores appear to be more reactive to stress, but also to be more responsive to treatment, suggesting the activation of a particular stress physiology by negative affective states that are not experienced.