The Monitoring Illicit Substance Use Consortium: A Study Protocol.

Objective: The global impact of substance use, including cannabis, amphetamine, cocaine, ecstasy, hallucinogens, and opioids, is increasing, although the overall prevalence is low. Australia and New Zealand are among the few regions of the world in which use (typically illicit) of these classes of substances remains within the top 10 causes of disease burden. The period of adolescence and young adulthood, during which substance use behaviors accelerate in prevalence, is associated with a particular risk for harm. However, the ability to study each substance class has been limited by their low population prevalence in single population-based cohort studies.

Method: The Monitoring Illicit Substance Use (MISUse) Consortium was established to address this problem by bringing together 4 mature prospective cohort studies across Australia and Zealand: Christchurch Health and Development Study (established 1977; 24 waves; N = 1,265), Australian Temperament Project (established 1983; 16 waves; N = 2,443), Victorian Adolescent Health Cohort Study (established 1992; 11 waves; N = 1,943), and International Youth Development Study (established 2002; 10 waves; N = 2,884).

Conclusion: The MISUse Consortium should enable well-powered studies of the natural history, developmental antecedents, and longer-term consequences of illicit substance use with a focus on identifying modifiable determinants of use that can be targeted in population-level policy and intervention responses.