[Effects on the brain of effective psychological treatments for anxiety disorders: a systematic review].

INTRODUCTION

Psychological therapies can modify thoughts, feelings, and behaviors of people with mental disorders, but the underlying brain mechanisms remain to be clarified. Advances in neuroimaging techniques can help us to understand of how different psychotherapies change the human brain. This review has aimed to systematically investigate the brain effects of psychological therapies for adults with anxiety disorders.

METHOD

Several electronic databases (Medline, PsycINFO, EMBASE and EBSCO) up to April 2010 were searched. Abstracts which appeared to fulfill the initial selection criteria (a structured psychological treatment in adults with anxiety disorders with at least one neuroimaging study performed before and after the treatment) were selected and their original articles were then retrieved. References from the selected English and Spanish language publications were also hand searched.

RESULTS

Eighteen studies met the criteria for inclusion in the review. The majority of these papers reported cognitive-behavioral therapy (CBT) in specific phobia, social phobia, obsessive-compulsive disorder (OCD), posttraumatic stress disorder or panic disorder. Psychological interventions changed neural circuits involved in the pathophysiology of anxiety disorders, especially activity in frontal-striatal circuits in OCD and prefrontal areas in arachnophobia. However, the results are largely inconsistent among themselves and with the neurobiological models of anxiety, in particular as regards the changes at the limbic level.

CONCLUSIONS

Despite the variety of methodological concerns, initial neuroimaging studies have showed that psychological interventions can change brain function related to anxiety disorders in the patients who respond to treatment. Neuromodulation mechanisms related to specific anxiety disorders remained to be elucidated. Future studies should delineate the process of “normalization” that occurs in the brain during a psychological treatment, helping to enrich the current neurobiological models of the origins, maintenance and treatment of anxiety disorders.