The role of epigenetics for understanding mental health difficulties and its implications for psychotherapy research.

Many mental health difficulties have developmental origins. Understanding the mechanisms for how psychosocial experiences are biologically embedded and influence lifelong development is a key challenge for the mental health disciplines. In recent years, epigenetic processes have emerged as a potential mechanism mediating the long-lasting vulnerability following the experience of adversity. Animal models provide evidence that early-life adversity can produce enduring epigenetic modifications in the brain, which mediate disorder-like behaviours, and there is emerging evidence to support that environmental factors influence epigenetic processes in humans. The investigation of DNA methylation, a chemical modification of the DNA with a role in gene regulatory processes, is becoming increasingly popular in psychological studies. A particular interest for the psychotherapy field lies in the potential for psychological interventions to influence epigenetic processes. Hence, the focus of this review will be on studies that have investigated intervention-associated changes in DNA methylation. Results of the first few studies will be critically reviewed, and a model of how therapy-associated changes of DNA methylation in peripheral, non-brain tissue might be useful as epigenetic biomarkers of treatment outcome will be presented. PRACTITIONER POINTS: Many mental health difficulties have substantial developmental origin. Epigenetic processes have emerged as a potential mechanism mediating the long-term effects of early adversity Epigenetic refers to cellular mechanisms that control gene expression states, independent of changes to the underlying DNA sequence. The epigenome can be highly dynamic and potentially influenced by external factors A particular interest for the psychotherapy field lies in the potential for psychological interventions to influence epigenetic processes.