Substance use, sleep and intervention design: insights from qualitative data.

: Alcohol and other drug use is associated with poor sleep quality and quantity, but there is limited qualitative research exploring substance users' experiences of sleep and few psychosocial sleep interventions for them. : To inform the development of psychosocial interventions to improve sleep amongst people reporting drug/alcohol problems. : Qualitative data were collected during a sleep survey. Of the 549 drug/alcohol users completing the survey, 188 (34%) provided additional information about their sleep using a free text box. Responses were analysed via Iterative Categorisation. Findings were reviewed with reference to the Behaviour Change Wheel (BCW). : All data were categorised inductively under five headings: (i) sleep quality; (ii) nature of sleep problems; (iii) sleep and substances; (iv) factors improving sleep quality; (v) factors undermining sleep quality. Substance use undermined sleep, but poor sleep often persisted after substance use had ceased. Sleep problems were diverse; as were the causes of, and strategies for dealing with, those problems. Causes and strategies had biological, psychological, social and environmental roots. : The BCW facilitated the identification of intervention components that might improve the sleep of people who use substances. These components relate to education, training, enablement, modelling, service provision, guidelines and environment.