BACKGROUND Cannabis use is referenced frequently in American popular music, yet it remains uncertain whether exposure to these references is associated with actual cannabis use. We aimed to determine if exposure to cannabis in popular music is associated independently with current cannabis use in a cohort of urban adolescents. METHODS We surveyed all 9th grade students at three large US urban...

AIMS To examine trends in patterns of cannabis use and related harm in the Australian population between 1993 and 2007. DESIGN Analysis of prospectively collected data from: (1) the National Drug Strategy Household Survey (NDSHS) and Australian Secondary Student Alcohol and Drug Survey (ASSADS); (2) the National Hospital Morbidity Database (NHMD); and (3) the Alcohol and Other Drug Treatment ...

BACKGROUND Cannabis use is decreasing in England and Wales, while demand for cannabis treatment in addiction services continues to rise. This could be partly due to an increased availability of high-potency cannabis. METHOD Adults residing in the UK were questioned about their drug use, including three types of cannabis (high potency: skunk; low potency: other grass, resin). Cannabis types we...

BACKGROUND Despite mounting evidence that use of and dependence on alcohol and cannabis are influenced by heritable factors, the extent to which heritable influences on these phenotypes overlap across the 2 substances has only rarely been explored. In the current study, we quantified cross-substance overlap in sources of variance and estimated the degree to which within-substance associations b...

BACKGROUND Resting-state functional connectivity is a noninvasive, neuroimaging method for assessing neural network function. Altered functional connectivity among regions of the default-mode network have been associated with both nicotine and cannabis use; however, less is known about co-occurring cannabis and tobacco use. METHODS We used posterior cingulate cortex (PCC) seed-based resting-s...

BACKGROUND Epidemiological studies show wide variability in the occurrence of cannabis smoking and related disorders across countries. This study aims to estimate cross-national variation in cannabis users' experience of clinically significant cannabis-related problems in three countries of the Americas, with a focus on cannabis users who may have tried alcohol or tobacco, but who have not used...

and tobacco smokers and 92 tobacco smokers with 81 non-smokers. They found a dose-response relationship between cannabis consumption and the degree of airways obstruction and hyperinflation. They estimated that one cannabis joint was equivalent to 2.5 cigarettes for the effect on forced expiratory volume in 1 s/forced vital capacity and to 6 cigarettes for the effect on specific airways conduct...

Previous studies have mostly shown positive effects of cannabis use on cognition in patients with schizophrenia, which could reflect lower neurocognitive vulnerability. There are however no studies comparing whether such cognitive differences have neuronal correlates. Thus, the aim of the present study was to compare whether patients with previous cannabis use differ in brain activation from pa...

BACKGROUND Attention-deficit/hyperactivity disorder (ADHD) and cannabis use are each associated with specific cognitive deficits. Few studies have investigated the neurocognitive profile of individuals with both an ADHD history and regular cannabis use. The greatest cognitive impairment is expected among ADHD Cannabis Users compared to those with ADHD-only, Cannabis use-only, or neither. METH...

BACKGROUND Increasing prevalence of recreational cannabis use among the young population has stimulated debate on the possible effects of acute and longterm use. AIMS To highlight recent knowledge of mechanisms of action, effects on psychomotor and cognitive performance, and health risks associated with cannabis consumption. METHOD A brief review of recent literature on the prevalence of re...