Abstract

Almost 70,000 Americans died from drug overdoses in 2019 alone, making drug addiction the world's largest cause of disability. Although while only a small percentage of long-term drug users develop addiction, little is known about the exact mechanisms behind this predisposition. Adversity in early life has a causal relationship to adult psychiatric illness and raises the possibility of addiction. Here, we review recent pre-clinical research that demonstrates how exposure to stress and/or drugs during adolescence controls changes in behaviour, gene expression, and the epigenome. Our review of the preclinical literature highlights research that show the frequently significant disparities between female and male subjects, as well as noteworthy results and gaps in the existing body of knowledge.