The molecular basis of psychotherapy: Focus on BDNF in talking therapies

Psychotherapy is effective in treating various types of mental disorders. However, the biological processes underlying its therapeutic efficacy in the relief of depression and anxiety remain unclear. An approach to investigating these therapeutic mechanisms derives from an understanding of disease pathogenesis, in which the dysfunction of brain-derived neurotrophic factor (BDNF) is strongly implicated. This study provides a review of various studies investigating the link between the efficacy of talking therapies in anxiety and depression and the measures of BDNF variability, the latter determined by plasma and serum BDNF concentrations, BDNF gene polymorphisms, and DNA methylation. Despite the few intriguing findings supporting the underlying hypothesis that reduced BDNF function results in poor response, many studies are limited by inadequate methodology and poor control of confounding factors. Thus, opportunities remain for further well-designed investigations, particularly utilizing the little-studied epigenetic factor of BDNF gene methylation.