Objectives: To compare depressive tendencies and level of work efficiency among patients treated with a biologic drug who suffer from hidradenitis suppurativa or a severe form of psoriasis. Patients and methods: An observational, retrospective study of couples was conducted in the out-patient department of Dermatology department of University Hospital Centre Split, in the period from March 2022 to June 2022. Twenty six patients with a severe form of HS and twenty six patients with severe psoriasis, treated with a biologic drug, were included. Respondents filled out a survey and three questionnaires: DLQI – Dermatology Life Quality Index, BDI – Beck's Depression Inventory II and Work Productivity and Activity Impairment Questionnaire: General Health V2.0 (WPAI:GH). Results: Patients suffering from HS had a statistically significantly worse quality of life, measured by the DLQI questionnaire, than patients with psoriasis (P=0,001). In both groups, men had worse results (P=0,038). Overall, 34.6% of HS patients and 7.7% of psoriasis patients reported symptoms of depression. A statistically significant difference in BDI-II scores was found between patients with psoriasis and patients with HS (P=0,001). The BDI-II score in the psoriasis group significantly correlated with the rated satisfaction with biologic therapy (rs=0,706, P<0,001). In the group with HS, the BDI-II score significantly correlated with the DLQI score (rs=0,702, P<0,001) and with the rated satisfaction with biologic therapy (rs=0,469, P=0,016). Patients with psoriasis rated their satisfaction with biologic therapy on the visual analogue scale significantly higher than patients with HS (P=0,035). The median time from the onset of symptoms to the official diagnosis for patients with HS was 4.5 years and for patients with psoriasis it was 2 years. The difference in diagnostic delay was found to be significant between the two groups (P=0,042). The results of the Work Productivity and Activity Impairment Questionnaire showed that there was a statistically significant difference between the diagnoses in the percentage of activity impairment due to health for all respondents (P=0,004). Conclusions: Patients with HS have more impaired quality of life, greater depressive tendencies, longer diagnostic delay and worse percentage of activity impairment due to health for all respondents than patients with psoriasis.