BACKGROUND: Internationally there is a lack of measurement on the impact of childcare on people who use drugs.

OBJECTIVES: The aim of this article was to longitudinally measure drug use, familial and social status and criminal involvement between parents and nonparents who use heroin and have children in their care.

METHODS: From 2003 to 2006, 404 participants were recruited to the Research Outcome Study in Ireland Evaluating Drug Treatment Effectiveness (ROSIE) as part of a longitudinal cohort study design. Participants completed the Maudsley Addiction Profile and 88% (n = 356) completed interviews at the 3-year period. One way between groups ANOVA with post hoc tests and backward, stepwise multiple regression were employed for analysis.

RESULTS: At follow-up, parents who had children in their care used heroin (p = .004), illicit methadone (p ≤ .001) and cocaine (p = .024) on fewer days than those who had no children, or those who had children but did not have children in their care. These differences were not observed at intake. Living with someone at intake who used drugs was found to be significantly associated with increased heroin (p ≤ .001), benzodiazepine (p = .039), and tobacco (p = .030) use at 3 years. Furthermore, a change in childcare status to caring for a child was associated with increased cannabis use (p = .025). Conclusion/Importance: While caring for children was associated with reduced heroin use at 3 years, living with a person who used at intake removed this effect, thus indicating that while individual based addiction theories reflected observed outcomes, social network connectedness was more influential.