OBJECTIVE: To evaluate the effect of psoriasis on quality of life of patients and DS in France. To highlight a relation between DS and quality of life for patients suffering from psoriasis. METHOD: Seven hundred fifty anonymous questionnaires (comprised two scales: the Psoriasis Disability Index [PDI] and the Center for Epidemiologic Studies - Depression scale [CES-D] were sent, via a Psoriasis Patient Support Group (APLCP). The CES-D, a short self-report scale composed of 20 items is a questionnaire designed to measure DS in the general population. The CES-D is widely used in epidemiological surveys on large populations. The PDI is a questionnaire specific for psoriasis patients. RESULTS: 297 questionnaires were returned (June 2002): response rate 39.6%. The sex ratio Men (M)/Women (W) was 47/53. Mean age: 48.8 years. Mean age of diagnosis: 26.3 years. The average to the total PDI score was 10.3 (s.d: 7.7 rank 0 to 39) i.e 22.8 (sd: 17.10) when reported to a scale of 0 to 100. Significant difference was observed between W and M for the global handicap score 24.53 vs 19.87 p <0.02. Two groups were identified: flare-up of psoriasis (49.5%), psoriasis not in flare-up (48%) - no answers (2.5%) - Psoriasis had a greater affect on patients with episode: PDI score=24.9 (s.d: 17.02) than patient without episode: PDI score=20.27 (s.d: 16.91). This difference was significant (p <0.05). In the studied population, 44.6% of the patients reported DS (CES-D+) whereas 55.4% did not (CES-D-). In CES-D+ patients the PDI score=30.98 (sd: 18.28) was higher than the score in CES-D-patients: PDI score=16.43 (sd: 13.97). This difference was significant (p <2.10-11). CONCLUSION: Patients in a current flare-up of psoriasis are more affected and feel more disabled in their daily life (higher disability score and higher frequency of DS) compared to patients without episode. Patients with DS (CES-D+), reported a higher impact of their psoriasis on their quality of life (PDI score 30.98 versus 16.43).