A Comparative Analysis of the Frequency of Bipolar Spectrum Disorder in Patients with and Without Psoriasis

Background: Psoriasis is a chronic disease that significantly negatively affects a patient’s quality of life. Based on etiopathological characteristics, there is strong evidence of susceptibility to psychological disorders, such as depression and bipolar disorder, in patients suffering from psoriasis. Objectives: We investigated the frequency of bipolar spectrum disorders in psoriasis patients compared to healthy controls in a selected population in Iran. Methods: This case-control study was conducted on two sample groups, with and without psoriasis (50 people in each group). The statistical population included all individuals referred to Shohadaye Tajrish and Taleghani Hospitals of Shahid Beheshti University of Medical Sciences, selected using the available method and assigned to two groups in 2023. The participants were examined for the presence of bipolar spectrum disorders using the Mood Disorder Questionnaire (MDQ) and the Bipolar Spectrum Diagnostic Scale (BSDS). Results: According to the MDQ questionnaire, the frequency rates of bipolar disorder in the patients and controls were 20% and 40%, respectively, with no significant difference between the groups (P = 0.108). Based on the BSDS, the frequency of bipolar disorder in the two groups, with and without psoriasis, was estimated to be 25% and 32.1%, respectively, with no significant difference (P = 0.226). The rate of major depressive disorders was also 22% and 26%, with no significant difference (P = 0.640). Conclusions: Among Iranian patients with psoriasis, the presence of the disease may not be associated with an increased risk of bipolar spectrum disorders.