Table 1a.

Characteristics of included studies (Search 1–3)

Study (number)	Study type	Sample size	Age	Population	Intervention	Comparison	Follow-up (years)	Attrition rate (%)	Outcome measure
Zonneyville-Bender MJS, et al., 2007 (1)	RCT	77	8–13	DBD; child psychiatric clinics & MH centres	UCPP; CBT + behavioural parent intervention	Care as usual & healthy controls	5	21	CSAP Youth survey (past month use)
Biederman J et al., 1999 (2)	Cohort study	260	15–17 (males)	75 with diagnosed ADHD, 137 control subjects; originally families were chosen from both psychiatric and non-psychiatric settings	ADHD medication	ADHD no medication & control group	4	19	DSM-III-R substance use disorder
Bucci S et al., 2010 (3)	Naturalistic evaluation	58	12–27	At “ultra high risk” or early psychosis; either non-users or current users of cannabis	Non-users: brief advice, +/− reinforcement users: intense therapy (MI and CBT) (more regular users received longer program duration)	None	1	43	OTI (past 28 days)

ADHD: Attention Deficit Hyperactivity Disorder; CBT: Cognitive Behavioural Therapy; DBD: Disruptive Behaviour Disorder; DSM-III-R: Diagnostic and Statistical Manual v3 Revised; MI: Motivational Interviewing; OTI: Opiate Treatment Index; UCPP: Utrecht Coping Power Program