Psychotherapy and Antidepressant Treatment Effects on the Functional Neuroanatomy of Depression

Abstract

The present review examines the functional neural correlates of the effects of antidepressant medication as well as psychological therapy in depression. There has been considerable evidence to suggest that antidepressant medications normalize dysfunctional activity in limbic regions, in particular the amygdala, as well as in subcortical and prefrontal regions in patients during processing of emotional and cognitive stimuli. Fewer studies to date have examined psychotherapy related brain changes in patients with depression, with some evidence for amygdala-hippocampal reductions following psychological therapies. There may be potential common therapeutic mechanisms of action with antidepressants and psychotherapy. The specificity of effects related to pharmacological and psychological therapies as well as to different classes of pharmacotherapy and effects due to improvements in the severity of depressive symptoms requires further investigation. Anterior cingulate activity as a predictor of clinical response before initiation of antidepressant treatment has been highly replicated, while evidence from CBT has been mixed. In order to derive clinical applications from these findings, machine learning methods have been applied to ascertain diagnosis and prognosis at the individual level with high accuracy. Future research should also aim to investigate whether integration of neuroimaging biomarkers based on multiple neural processes, such as affective and cognitive processing and structural neuroimaging, would achieve more accurate classification. This would help to optimize treatment strategies which are particularly important for those patients who may be less likely to benefit from the usual initial therapies.