The association of oxidative stress and inflammatory response with psychiatric comorbidity and cognitive functions in patients with psoriasis

Psoriasis is a common, chronic, inflammatory skin disease with the prevalence of %1-2. Because of its effect on quality of life and cardiovascular, metabolic and psychiatric comorbidites, psoriasis is defined as a systemic disease rather than a disease limited to the skin. Psoriasis is known as a multisystemic disease with chronic inflammation.Increased proinflammatory cytokines are also thought to be associated with both psychiatric comorbidities and cognitive impairment as a result of microvascular damage, atherogenesis and neuronal stress. In agreement with all these assumptions, we aimed to compare psychiatric comorbidities and neurocognitive functions, oxidative stress markers TOS, TAS and OSI, and proinflammatory cytokines TNF-alpha and IL-6 levels in psoriasis patients with healthy controls and to assess the effects of oxidative stress and inflammation on psychiatric comorbidity and cognitive functions. A total of 37 patients followed up in dermatology department, with the diagnosis of psoriasis and sociodemographically matched 37 healthy volunteers were included in the study. Serum levels of TNF-alpha, IL-6, TOS and OSI were higher in psoriasis group. Beck Depression Inventory, Beck Anxiety Inventory scores were statistically significantly higher in patients with psoriasis compared to the control group. In this study we found that the number of categories completed in the Wisconsin card matching test and the recall, learning and verbal fluency scores in psoriasis patients were significantly lower than the control group. However, no significant difference was found between the psoriasis patients and healthy controls in the neurocognitive test scores evaluating split attention, processing memory. At the same time, it was found that the impairment in learning, remembrance, verbal fluency in psoriasis patients were not associated with oxidative stress, inflammation and depression, anxiety levels. We suggest that further studies with larger sample should be done to better understand the underlying mechanisms of the neurocognitive impairment in psoriasis patients.