A large number of studies with considerably variable methods have been performed to investigate brain regions involved in the pathophysiology of major depressive disorder. The aim of this study was to use a quantitative meta-analytic technique to synthesize the results of much of this research.
Three separate quantitative meta-analytical studies were conducted using the activation likelihood estimation technique. Analysis was performed of studies conducted at rest comparing brain activation in patients with depression and controls, studies conducted of brain changes associated with antidepressant medication treatment and studies comparing brain activation patterns induced by the induction of positive or negative emotion in patients with depression compared with controls.
The results of the study indicated a complex series of areas of the brain implicated in the pathophys-iology depression. This included a network of dorsal regions that are hypoactive in depressed subjects and increase in activity with treatment and a corresponding set of subcortical and limbic regions in which opposite changes are found.
The pathophysiology of major depressive disorder involves a complicated series of networks of frontal, temporal-parietal cortical and limbic brain regions and the cerebellum. Questions remain as to whether one or other of these networks play a primary role in the etiology of the disorder.