Substance use and common child mental health problems: examining longitudinal associations in a British sample.
OBJECTIVE
To examine the longitudinal associations in both directions between mental health and substance use in adolescence.


METHODS
Three-year longitudinal cohort.


METHODS
Britain (nationally representative sample).


METHODS
3607 youths aged 11-16 years at baseline.


METHODS
Externalizing and internalizing mental health problems were measured using brief questionnaires (parent-reported Strengths and Difficulties Questionnaire) and diagnostic interviews, including clinician-rated diagnoses of mental disorder. Substance use was measured by youth self-report, and included regular smoking, frequent alcohol consumption, regular cannabis use and ever taking other illicit drugs.


RESULTS
Externalizing (specifically behavioural) problems at baseline independently predicted all forms of substance use, with a particularly strong effect on smoking. In all cases this association showed a dose-response relationship. In contrast, although internalizing problems had a strong univariable association with smoking, this disappeared after adjusting for comorbid externalizing problems. There was little or no evidence that baseline substance use predicted mental health at follow-up.


CONCLUSIONS
Externalizing problems predict adolescent substance use, and adjusting for comorbid externalizing problems is vital when investigating the effects of internalizing problems. A dose-response effect of externalizing problems is seen across the full range. Programmes seeking to prevent adolescent substance use by reducing externalizing problems may therefore wish to consider population-wide interventions rather than targeting individuals only at the negative extreme.
Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK. anna.goodman@lshtm.ac.uk
Anna
A
Goodman
D000293:Adolescent; D000328:Adult; D000428:Alcohol Drinking / Q000453:epidemiology*; D019958:Attention Deficit and Disruptive Behavior Disorders / Q000453:epidemiology / Q000523:psychology; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology / Q000523:psychology; D001523:Mental Disorders / Q000453:epidemiology*; D000297:Psychology, Adolescent; D012907:Smoking / Q000453:epidemiology* / Q000523:psychology; D019966:Substance-Related Disorders / Q000453:epidemiology* / Q000523:psychology; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult