Preventing mental disorders in children: a systematic review to inform policy-making

At any given time, 14% of Canadian children experience clinically significant mental disorders, which frequently persist into adulthood. Canadian public policy has emphasized specialized treatment services, yet these services only reach 25% of children with disorders. Prevention programs hold potential to reduce the number of children with disorders in the population. To inform policy-making, we systematically reviewed the best available research evidence on programs for preventing conduct disorder (CD), anxiety and depression, three of the most prevalent mental disorders in children.

We systematically identified and reviewed randomized controlled trials (RCTs) on programs intended to prevent CD, anxiety and depression in children aged 0-18 years.

Fifteen RCTs met selection criteria: nine (on eight programs) for preventing CD; one for anxiety; four (on three programs) for depression; and one for all three. Ten RCTs demonstrated significant reductions in child symptom and/or diagnostic measures at follow-up. The most noteworthy programs, for CD, targeted at-risk children in the early years using parent training (PT) or child social skills training (SST); for anxiety, employed universal cognitive-behavioural training (CBT) in school-age children; and for depression, targeted at-risk school-age children, also using CBT. Effect sizes for these noteworthy programs were modest but consequential. There were few Canadian studies and few that evaluated costs.

Prevention programs are promising but replication RCTs are needed to determine effectiveness and cost-effectiveness in Canadian settings. Four program types should be priorities for replication: targeted PTand child SST for preventing CD in children's early years; and universal and targeted CBTfor preventing anxiety and depression in children's school-age years. Conducting RCTs through research-policy partnerships would enable implementation in realistic settings while ensuring rigorous evaluation. Prevention merits new policy and research investments as part of a comprehensive public health strategy to improve children's mental health in the population.