Cognitive impairment and affective temperament in patients with psoriasis

Introduction. Psoriasis is a chronic inflammatory skin disease, and in its pathogenesis psychological factors are involved. The functioning of working memory is associated mainly with the activity of the dorsolateral prefrontal cortex, the brain region responsible for the most complex cognitive and emotional functions.

Objective . The aim of the study was to evaluate the frontal cognitive functions, symptoms of depression and affective temperament in patients with psoriasis, and to assess the relationship between the severity of affective temperament traits, and neuropsychological dysfunctions and depression.

Material and methods . The study included 125 persons (97 patients with psoriasis and 28 healthy people). To assess the dorsolateral prefrontal cortex, the trail-making test (TMT) and Stroop test were used. Severity of psoriasis was assessed by PASI score and severity of depressive symptoms by Beck depression scale. To evaluate affective temperament, the TEMPS-A scale was used.

Results . In patients with psoriasis depressive disorders are more common. Patients achieve worse results than healthy people in neuropsychological tests assessing processes of memory and executive functions, and present specific features of affective temperament, in particular a higher level in the dimension of depression, anxiety and irritability. Depressive temperament, irritability and anxiety may predispose to affective disorders and cognitive dysfunction in psoriasis, while the hyperthymic dimension of the affective temperament characteristic is associated with lower risk of this disorders.

Conclusions . Our results have shown the importance of affective temperament evaluation (TEMPS-A scale), and cognitive dysfunction disclosed by neuropsychological assessment of frontal functions.