Evaluation of Visual Information Processing Speed in Depressed People

Depression disorders are associated with serious dysfunction and depressive symptoms. Cognitive slowing is a clear symptom observed in all depressed people. PVSAT is a measure of cognitive function that specifically assesses visual information processing speed and flexibility, as well as calculation ability. The aim of the present study was to determine whether the Paced Visual Serial Addition Test (PVSAT) might constitute a useful procedure for assessing cognitive functions in depressive disorder. Twenty – eight depressed patients, together with fourteen healthy control (HC) subjects participated in the study. All participants performed the PVSAT and a set of clinical tasks assessing information processing speed, working memory and executive functions. Compared with the HCs, the depressed patients were significantly impaired in their performance of the PVSAT. Significant impairment (compared with controls) was also evidenced by only one of the clinical tasks – the symbol coding task, which assesses information processing speed. Our results demonstrate the high sensitivity of the PVSAT to cognitive impairment. However, correlation analyses showed that the main factor explaining the depressed patients PVSAT impairment was cognitive slowing.