[Executive functions in patients with depression. The role of prefrontal activation]

Depression is a multifarious disease, having an impact on most aspects of everyday life. Cognitive deficits cause considerable impairments and restraints in performance and have become one of the major clinical and research foci in recent years. According to previous work, deficits in executive functioning seem to be particularly prominent. At present only a few functional neuroimaging studies investigated the neurofunctional correlates aimed at these deficits by using specific activation tasks. These findings are somewhat controversial, revealing prefrontal hypo- as well as hyperactivation as a substrate of executive performance. This paper reviews current functional neuroimaging findings within a framework of depression as a dysfunction in limbic-cortical circuits. As a conclusion, the concept of "simple" hypofrontality does not offer a satisfactory explanation. Rather, a more dynamic model will be necessary in order to achieve a more realistic concept of executive deficits in depression.