Evaluation of serum brain-derived neurotrophic factor to assess the association between psoriasis and depression

Background: Psoriasis patients usually experience problems pertaining to body image, low selfesteem, anxiety, and depression. Brain-derived neurotrophic factor (BDNF) has been used as a marker of depression. Objective: To assess the association between depression and psoriasis objectively by analysis of serum BDNF levels. Patients and methods: Ninety participants were divided into three equal groups: the psoriasis group, the depression group, and the healthy control group. The psoriasis area severity index was assessed in psoriatic patients. The 30 patients with depression were diagnosed according to the Diagnostic and statistical manual of mental disorders. All participants were assessed by the Beck depression inventory scale and the life stress inventory scale. BDNF serum level was measured in all participants using the quantitative sandwich enzyme immunoassay technique. Results: Psoriasis patients presented with different degrees of severity. In the psoriasis group, the mean BDNF level was significantly lower in depressed patients than in those who were not suffering from depression (P 0001). BDNF levels were significantly lower in both psoriasis patients with depression (P 0.0001) and depressed patients (P 0.001) compared with the control group. A significant correlation was found between BDNF levels and both the life stress and Beck scale (P 0.001) and the duration of psoriasis (P 0.01). In contrast, the severity of psoriasis had no impact on BDNF levels. Conclusion: The serum BDNF levels decreased in depressed patients and in psoriasis patients compared with normal healthy individuals. Evaluation of BDNF levels could be used as an objective measure of depression in psoriatic patients.