Early childhood predictors of age of initiation to use of cannabis: A birth prospective study


  • Reza Hayatbakhsh PhD, MD, Principle Research Officer, Gail M. Williams PhD, Professor, William Bor MBBS, FRANZCP, Doctor, Jake M. Najman PhD Professor.

Correspondence to Dr Reza Hayatbakhsh, School of Population Health, University of Queensland, Herston Road, Herston, Qld 4006, Australia. Tel: +61 7 3346 4638; Fax: +61 7 3365 5509; E-mail: m.hayatbakhsh@uq.edu.au


Introduction and Aims

Early age of cannabis use predicts subsequent illicit drug abuse and other psychosocial problems. Identification of factors associated with early cannabis use may contribute to the development of preventive interventions. This study aimed to examine the early life predictors of age of initiation to cannabis.

Design and Methods

Data were from Mater Hospital and University of Queensland Study of Pregnancy, a population-based prospective birth cohort study. Participants were a cohort of 3488 young adults who self-reported frequency and age of onset of cannabis use at the 21 year follow up.


Of 3488 young adults, 48.9% (51.8% men and 46.4% women) reported having ever used cannabis. For those who had ever used cannabis, age of onset had mean and median of 15.8 and 16.0 years, respectively. In multivariate analysis child's gender, change in maternal marital status, quality of marital relationship, maternal cigarette smoking and alcohol consumption and maternal depression when the child was 5 years statistically significantly predicted age of initiation to cannabis use.

Discussion and Conclusions

The present study explores the impact of early childhood factors associated with age of onset of cannabis use. It is suggested that the family environment within which children are reared, including factors such as parents' marital circumstances, has a major influence on initiation to cannabis use in adolescence. Research is needed to disentangle the pathways of association between these early life factors and early initiation to use of cannabis.