Circadian rhythms, sleep, and substance abuse

Abstract

Substance abuse is linked to numerous mental and physical health problems, including disturbed sleep. The association between substance use and sleep appears to be bidirectional, in that substance use may directly cause sleep disturbances, and difficulty sleeping may be a risk factor for relapse to substance use. Growing evidence similarly links substance use to disturbances in circadian rhythms, although many gaps in knowledge persist, particularly regarding whether circadian disturbance leads to substance abuse or dependence. Given the integral role circadian rhythms play in regulating sleep, circadian mechanisms may account in part for sleep-substance abuse interactions. Furthermore, a burgeoning research base supports a role for the circadian system in regulating reward processing, indicating that circadian mechanisms may be directly linked to substance abuse independently of sleep pathways. More work in this area is needed, particularly in elucidating how sleep and circadian disturbance may contribute to initiation of, and/or relapse to, substance use. Sleep and circadian-based interventions could play a critical role in the prevention and treatment of substance use disorders.

Copyright © 2011 Elsevier Ltd. All rights reserved.

Figures

Figure 1

Conceptual model of circadian and sleep pathways to substance abuse. The solid arrows reflect the rich literature supporting bidirectional effects between sleep and substance abuse, and the cumulative human and animal evidence supporting the acute effects of substance use on circadian parameters. The hatched arrows reflect for hypothetical pathways awaiting more research attention, including direct circadian effects on substance abuse, and the reward system-mediated effect of circadian misalignment on substance abuse.