Handbook on the State of the Art in Applied Psychology

CHAPTER 7Epigenetic Processes Mediating Environments, Experiences, and Mental Health: Therapeutic and Diagnostic Implications

Moshe Szyf

Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada

Abstract

There is overwhelming evidence that exposure and experiences shape long‐term health outcomes including mental and physical disorders. The mechanism through which exposures and experiences modulate or even override genetic predisposition has been a mystery. DNA methylation is a chemical mark on DNA that is laid down during gestational development. Different cells in the body acquire different profiles of DNA methylation marks, which explains how the same genome can encode a vast array of different cell types and organs as seen in a multicellular organism like humans. Data that have emerged in the last 13 years suggest a similar process might be modulating stable gene functions in response to experiences and exposures, allowing similar genes to perform different functions in response to different experiential history. DNA methylation marks, as opposed to genetic mutations, are reversible by either pharmacological or behavioral strategies and therefore offer the potential for reversing or preventing disease including mental health disorders. In addition, mapping DNA methylation profiles could provide tools for prediction and diagnosis of disease. This chapter highlights the data that support the hypothesis that DNA methylation has implications for ...