title: Relation between age of first drinking and mental health and alcohol and drug disorders in adulthood: evidence from a 35-year cohort study.
abstract: OBJECTIVE
  To estimate associations between age of first drinking (AFD) and alcohol use disorder, nicotine dependence, cannabis dependence, illicit drug dependence, major depression and anxiety disorder in adulthood, net of a series of covariate factors.
  
  
  METHODS
  Data were obtained from a longitudinal birth cohort.
  
  
  METHODS
  Christchurch, New Zealand.
  
  
  METHODS
  The Christchurch Health Development Study (CHDS), a longitudinal study of a cohort born in 1977 and studied to age 35 years. Analysis samples ranged in size from 1056 (ages 11-13 years) to 962 (age 35 years); 50.2% of the total sample was male.
  
  
  METHODS
  A measure of AFD (ages 5-13+ years) was generated using latent class analysis. Outcome measures included: major depression, anxiety disorders, alcohol use disorder, nicotine dependence, cannabis dependence and other illicit drug dependence during the period 15-35 years. Covariate factors measured during childhood included family socio-economic status, family functioning, parental alcohol-related attitudes/behaviours and individual factors.
  
  
  RESULTS
  Earlier AFD was associated significantly (P < 0.05) with increased risk of later alcohol use disorders, nicotine dependence and illicit drug dependence, and was associated marginally (P < 0.10) with cannabis dependence, but not depression or anxiety disorder. After controlling for covariate factors, the associations between AFD and outcomes were no longer statistically significant [alcohol use disorder: B = -0.07, 95% confidence interval (CI) = -0.22, 0.08; nicotine dependence: B = -0.15, 95% CI = -0.34, 0.04; illicit drug dependence: B = -0.29, 95% CI = -0.73, 0.15; cannabis dependence: B = -0.05, 95% CI = -0.31, 0.22].
  
  
  CONCLUSIONS
  The associations between age of first drinking and later alcohol/drug disorders appear to be accounted for at least to some degree by factors related to characteristics of the individual and family during childhood.
authors.affiliation: Department of Psychological Medicine, University of Otago, Wellington, New Zealand.
authors.forename: G
authors.initials: G
authors.lastname: Newton-Howes
authors.affiliation: Christchurch Health and Development Study, Department of Psychological Medicine, University of Otago, Christchurch, New Zealand.
authors.forename: J M
authors.initials: JM
authors.lastname: Boden
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000428:Alcohol Drinking / Q000453:epidemiology* / Q000523:psychology; D001008:Anxiety Disorders / Q000453:epidemiology* / Q000523:psychology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000453:epidemiology* / Q000523:psychology; D005260:Female; D006801:Humans; D013287:Illicit Drugs; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology / Q000523:psychology; D009520:New Zealand; D012307:Risk Factors; D019966:Substance-Related Disorders / Q000453:epidemiology*; D014029:Tobacco Use Disorder / Q000453:epidemiology / Q000523:psychology; D000066608:Underage Drinking / Q000523:psychology* / Q000706:statistics & numerical data*; D055815:Young Adult
chemical_list: D013287:Illicit Drugs
keywords: Age first drinking; alcohol use disorder; birth cohort; epidemiology; outcomes