Cognitive dysfunction and depressive symptoms seem to play significant role in clinical picture of hyperthyroidism.

The aim of this study was to assess cognitive functions connected with prefrontal cortex in relation to intensity of depressive symptoms in patients with Graves-Basedow disease.

The studied group consisted of 45 patients (37 female, 8 male) aged 18-55 (mean 42,2) with Graves-Basedow disease. The control group consisted of 30 healthy persons matched with age, gender and education for experimental group. The Neuropsychological assessment included the Wisconsin Card Sorting Test (WCST) and N-back test (1-back) for different aspects of working memory and executive functions estimation. The intensity of depressive symptoms were assessed by Beck Depression Inventory.

Investigated patients show significant impairments on performance on all parameters of WCST compared to healthy persons. Also the results of N-back test show severe disturbances on visuospatial working memory on 1-back task.

The results show significant disturbances on frontal function (particularly working memory and executive functions) in patients with Graves-Basedow disease in relation to healthy subjects. In 1/3 patients with Graves-Basedow disease the intensity of depressive symptoms was observed. The higher intensity of depressive symptoms were correlated with grater cognitive deficits in the neuropsychological tests. These results suggest that depressive symptoms may increase cognitive deficits, especially connected with prefrontal cortex in the group of Graves-Basedow disease patients.