Determining the cognitive performance in the first episode of depression

The most recent evidence suggest that cognitive dysfunction is a nuclear symptom of major depressive disorder (MDD), which in turn mediates the psychosocial functioning of depressed patients. However, few studies have determined whether cognitive disturbances are observable in the first stages of the disorder as some authors have described the worse cognitive performance in both first episode and recurrently depressed patients, others have reported small impairments across most cognitive domains. Such disparity may be accounted for by a great heterogeneity of cognitive profiles among patients that have not been taken much into account. The chapter goes on to briefly review the history of cognitive performance in MDD and to discuss the necessity of determining the cognitive dysfunction in the early stages of the disorder. The chapter concludes with the consideration of cognitive impairment alongside core depressive symptoms to direct efforts toward full recovery of patients from the very beginning of MDD.