Context: Selective interventions targeting personality risk are showing promise in the prevention of problematic drinking behavior, but their effect on illicit drug use has yet to be evaluated.
Objective: To investigate the efficacy of targeted coping skills interventions on illicit drug use in adolescents with personality risk factors for substance misuse.
Design: Randomized controlled trial.
Setting: Secondary schools in London, United Kingdom.
Participants: A total of 5302 students were screened to identify 2028 students aged 13 to 16 years with elevated scores on self-report measures of hopelessness, anxiety sensitivity, impulsivity, and sensation seeking. Seven hundred thirty-two students provided parental consent to participate in this trial.
Intervention: Participants were randomly assigned to a control no-intervention condition or a 2-session group coping skills intervention targeting 1 of 4 personality profiles.
Main outcome measures: The trial was designed and powered to primarily evaluate the effect of the intervention on the onset, prevalence, and frequency of illicit drug use over a 2-year period.
Results: Intent-to-treat repeated-measures analyses on continuous measures of drug use revealed time x intervention effects on the number of drugs used (P < .01) and drug use frequency (P < .05), whereby the control group showed significant growth in the number of drugs used as well as more frequent drug use over the 2-year period relative to the intervention group. Survival analysis using logistic regression revealed that the intervention was associated with reduced odds of taking up the use of marijuana (beta = -0.3; robust SE = 0.2; P = .09; odds ratio = 0.7; 95% confidence interval, 0.5-1.0), cocaine (beta = -1.4; robust SE = 0.4; P < .001; odds ratio = 0.2; 95% confidence interval, 0.1-0.5), and other drugs (beta = -0.7; robust SE = 0.3; P = .03; odds ratio = 0.5; 95% confidence interval, 0.3-0.9) over the 24-month period.
Conclusion: This study extends the evidence that brief, personality-targeted interventions can prevent the onset and escalation of substance misuse in high-risk adolescents.
Trial registration: clinicaltrials.gov Identifier: NCT00344474.