CANNABIS IS STRONGEST PREDICTOR OF LIFETIME ILLICIT DRUG USE
DATA FROM 1,265 CHILDREN ACROSS 25 YEARS
“The use of cannabis in late adolescence and early adulthood is the strongest risk factor for later involvement in other illicit drugs,” confirms a study led by Professor David Fergusson at the Department of Psychological Medicine at Christchurch School of Medicine and Health Sciences. It was published in Drug and Alcohol Dependence 2008 (96:165-177).
The 25-year longitudinal study examined the “developmental antecedents” of illicit drug use and abuse/dependence in a “birth cohort” of 1,265 New Zealand children, including cannabis use to age 25, parental adjustment, exposure to childhood sexual/ physical abuse and interparental violence, novelty-seeking, childhood and early adolescent adjustment and substance use, and affiliation with substance-using peers.
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.
Illicit drug use and abuse/dependence from ages 16 to 25 were significantly linked with a range of parental adjustment measures, exposure to abuse in childhood, individual factors and childhood and early adolescent adjustment.
The current study suggested that the illicit drug use and abuse/dependence were linked to a range of early life circumstances and processes which put people 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.
The developmental antecedents of illicit drug use: Evidence from a 25-year longitudinal study by David M Fergusson ∗, Joseph M Boden, L John Horwood.
*Department of Psychological Medicine, University of Otago, Christchurch School of Medicine and Health Sciences, Christchurch 8140, New Zealand
The full report is available online – click here.