Abstract
People who use substances commonly experience sleep disruptions, affecting the regulation of physical and mental health, and presenting a significant barrier to treatment success. Sleep impairments are noted in all phases of substance use; however, differences between subjective versus objective methods used to measure sleep quality have been reported. While polysomnography is the gold-standard for sleep measurement, recent advances in actigraphy may help address the discordance between subjective and objective sleep reports. This systematic review examined emerging evidence (2016-present) for sleep impairment in people who use substances, with the twofold goal of: (1) identifying whether sleep outcomes vary across substance type (alcohol, nicotine, cannabis, cocaine, methamphetamine and opioids); and (2) contrasting results from subjective and objective measures. While some differences between subjective and objective sleep were noted, there was overwhelming evidence of clinically relevant sleep impairment in people who use alcohol, nicotine, cocaine, methamphetamine and opioids, with less consistent results for cannabis. Gaps in the literature are identified and future recommendations are presented, including utilization of common methodological frameworks, identification of mechanisms, and closer examination of sleep across stages of substance use and the interconnection between sleep and return to use.