Implications of circadian rhythm and stress in addiction vulnerability [version 1; referees: 2 approved]

In the face of chronic stress, some individuals can maintain normal function while others go on to develop mental illness. Addiction, affecting one in every twelve people in America, is a substance use disorder long associated with stressful life events and disruptions in the sleep/wake cycle. The circadian and stress response systems have evolved to afford adaptability to environmental changes and allow for maintenance of functional stability, or homeostasis. This mini-review will discuss how circadian rhythms and stress individually affect drug response, affect each other, and how their interactions may regulate reward-related behavior. In particular, we will focus on the interactions between the circadian clock and the regulation of glucocorticoids by the hypothalamic-pituitary-adrenal (HPA) axis. Determining how these two systems act on dopaminergic reward circuitry may not only reveal the basis for vulnerability to addiction, but may also illuminate potential therapeutic targets for future investigation. This article is included in the How clocks affect channel. resilience in biological systems Colleen McClung ( ) Corresponding author: [email protected] Becker-Krail D and McClung C. How to cite this article: Implications of circadian rhythm and stress in addiction vulnerability [version 1; 2016, :59 (doi: ) referees: 2 approved] F1000Research 5 10.12688/f1000research.7608.1 © 2016 Becker-Krail D and McClung C. This is an open access article distributed under the terms of the Copyright: Creative Commons Attribution , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Licence The author(s) declared that no grants were involved in supporting this work. Grant information: Competing interests: No competing interests were disclosed. 13 Jan 2016, :59 (doi: ) First published: 5 10.12688/f1000research.7608.1 Referee Status: