Background and aimsDespite the high prevalence and negative effects of hazardous substance use, few young adults enter treatment. Community Reinforcement and Family Training (CRAFT), a support programme for concerned significant others of people with substance use disorders, has proved efficacious in promoting treatment entry. The aim of the current trial was to compare the efficacy of CRAFT with an active control for parents of young adults (aged 18-24 years) with hazardous substance use.DesignThis was a randomized controlled superiority trial comparing CRAFT (n = 58) with an active control group receiving manualized counselling (n = 55), with outcome assessments at 6, 12 and 24 weeks (primary end-point). A sequential design with a stopping rule was added post recruitment commencement.SettingThe study took place in two outpatient clinics for young adults in Stockholm, Sweden, and subsequently via video-conference due to COVID-19.ParticipantsBetween October 2018 and May 2021, 113 participants (92% female) who were parents of young adults (87% male) were recruited. Recruitment was discontinued when 70% of the planned sample had been recruited, following an interim analysis of the primary outcome showing no difference between conditions.Intervention and comparatorParticipants were randomized (ratio 1 : 1) to eight manual-based individual CRAFT sessions or five individual manual-based counselling sessions + one voluntary psychoeducative group session, delivered over maximum 14 weeks.MeasurementsThe primary outcome measure was the rate of young adult entry in substance use treatment during the trial period (24 weeks).FindingsAt the 24 weeks follow-up, 19 (33%) of CRAFT participants and 17 (31%) of counselling participants had reported young adult treatment entry, with no difference between conditions (odds ratio CRAFT versus counselling 0.84, 95% confidence interval = 0.35; 1.99, P = 0.700). Both conditions reported clinically relevant reductions in young adult substance use, but no change in participants' levels of depression, anxiety or stress.ConclusionsThis trial showed no statistically significant evidence that Community Reinforcement and Family Training (CRAFT), a support programme for concerned significant others of people with substance use disorders, is more efficacious than manual-based counselling regarding treatment entry for young adults.