Background. Studies measuring the effects of psychotherapy on brain function are under-represented relative to analogous studies of medications, possibly reflecting historical biases. However, psychological constructs relevant to several modalities of psychotherapy have demonstrable neurobiological correlates, as indicated by functional neuroimaging studies in healthy subjects. This review examines initial attempts to measure directly the effects of psychotherapy on brain function in patients with depression or anxiety disorders.
Method. Fourteen published, peer-reviewed functional neuroimaging investigations of psychotherapy were identified through a MEDLINE search and critically reviewed. Studies were compared for consistency of findings both within specific diagnostic categories, and between specific modalities of psychotherapy. Results were also compared to predicted neural models of psychotherapeutic interventions.
Results. Behavioral therapy for anxiety disorders was consistently associated with attenuation of brain-imaging abnormalities in regions linked to the pathophysiology of anxiety, and with activation in regions related to positive reappraisal of anxiogenic stimuli. In studies of major depressive disorder, cognitive behavioral therapy and interpersonal therapy were associated with markedly similar changes in cortical–subcortical circuitry, but in unexpected directions. For any given psychiatric disorder, there was only partial overlap between the brain-imaging changes associated with pharmacotherapy and those associated with psychotherapy.
Conclusions. Despite methodological limitations, initial neuroimaging studies have revealed convergent and mechanistically sensible effects of psychotherapy on brain function across a range of psychiatric disorders. Further research in this area may take advantage of emerging neuroimaging techniques to explore a broader range of psychotherapies, with the ultimate goal of improving clinical decision-making and treatment.