The developmental antecedents of illicit drug use: evidence from a 25-year longitudinal study.
BACKGROUND
The present study examined the developmental antecedents of illicit drug use and abuse/dependence.


METHODS
A 25-year prospective longitudinal study of the health, development, and adjustment of a birth cohort of 1265 New Zealand children. Measures included assessments of adolescent and young adult illicit drug use and abuse/dependence; cannabis use to age 25; measures of parental adjustment; measures of exposure to childhood sexual abuse, physical abuse, and interparental violence; novelty-seeking; childhood and early adolescent adjustment and substance use; and affiliation with substance-using peers.


RESULTS
Illicit drug use and abuse/dependence from ages 16 to 25 were significantly associated (all p values<.05) with a range of parental adjustment measures; exposure to abuse in childhood; individual factors; and measures of childhood and early adolescent adjustment. Analyses using repeated measures logistic regression models suggested that parental illicit drug use, gender, novelty-seeking, and childhood conduct disorder predicted later illicit drug use and abuse/dependence. Further analyses revealed that these pathways to illicit drug use and abuse/dependence were mediated via cannabis use, affiliation with substance-using peers, and alcohol use during ages 16-25.


CONCLUSIONS
The current study suggested that the illicit drug use and abuse/dependence were associated with a range of early life circumstances and processes that put individuals at greater risk of illicit drug use and abuse/dependence. However, the use of cannabis in late adolescence and early adulthood emerged as the strongest risk factor for later involvement in other illicit drugs.
Fergusson
David M
DM
Department of Psychological Medicine, University of Otago, Christchurch School of Medicine and Health Sciences, Christchurch 8140, New Zealand. dm.fergusson@otago.ac.nz <dm.fergusson@otago.ac.nz>
Boden
Joseph M
JM
Horwood
L John
LJ
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002649:Child Abuse / Q000523:psychology / Q000706:statistics & numerical data; D015331:Cohort Studies; D019955:Conduct Disorder / Q000453:epidemiology / Q000523:psychology; D006801:Humans; D013287:Illicit Drugs / Q000009:adverse effects*; D008016:Life Change Events; D008137:Longitudinal Studies; D015233:Models, Statistical; D009520:New Zealand / Q000453:epidemiology; D010290:Parents / Q000523:psychology; D010379:Peer Group; D011446:Prospective Studies; D000297:Psychology, Adolescent / Q000706:statistics & numerical data; D002666:Psychology, Child; D012044:Regression Analysis; D012307:Risk Factors; D012917:Social Adjustment; D019966:Substance-Related Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology
D013287:Illicit Drugs