The present study used a multilevel approach with multiple informants to determine whether, at individual level, association with substance-using peer groups, and, at class level, incidences of intoxicated students in school premises, are related to students' own substance use. Additionally, it tested the hypothesis that such school incidences affect the closeness of the relation between associ...

INTRODUCTION We examine whether regular cigarette smokers were more likely to be exposed to and use cannabis at an earlier age, and further, upon initiation, whether their initial experiences with cannabis varied from those reported by never/non-regular cigarette smokers. METHOD A sample of 3797 Australian twins and siblings aged 21-46 years was used. Survival analyses examined whether cigare...

PURPOSE OF REVIEW A rational cannabis policy would arguably be one that minimized the harms of both cannabis use and the legal policies adopted to control its use. We, therefore, review recent epidemiological evidence on the harmful effects of cannabis use and social research on the costs and benefits of cannabis prohibition. RECENT FINDINGS Epidemiological evidence suggests that cannabis inc...

A key question in the ongoing policy debate over cannabis' legal status is whether liberalizing cannabis laws leads to an increase in cannabis use. This paper provides new evidence on the impact of a specific type of liberalization, decriminalization, on initiation into cannabis use. Our identification strategy exploits variation in the timing of cannabis policy reforms and our estimation frame...

BACKGROUND There is increasing debate about cannabis use for medical purposes, including for symptomatic treatment of chronic pain. We investigated patterns and correlates of cannabis use in a large community sample of people who had been prescribed opioids for chronic non-cancer pain. METHODS The POINT study included 1514 people in Australia who had been prescribed pharmaceutical opioids for...

BACKGROUND With the Canadian government legalizing cannabis in the year 2018, the potential harms to certain populations-including those with opioid use disorder-must be investigated. Cannabis is one of the most commonly used substances by patients who are engaged in medication-assisted treatment for opioid use disorder, the effects of which are largely unknown. In this study, we examine the im...

BACKGROUND Cannabis is one of the most highly abused illicit drugs in the world. Several studies suggest a link between adolescent cannabis use and schizophrenia. An understanding of this link would have significant implications for legalization of cannabis and its medicinal value. The present study aims to determine whether familial morbid risk for schizophrenia is the crucial factor that unde...