AIMS To estimate long-term trends in cannabis use and projections of schizophrenia assuming a causal relation between cannabis use and schizophrenia. METHODS Trends in cannabis use were estimated from a national survey, 2003; and incidence of schizophrenia was derived from surveys in three English cities, 1997-99. A difference equation cohort model was fitted against estimates of schizophreni...

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 Initiation of cannabis use typically follows alcohol use, but the reverse order does occur and is more common for African-Americans (AAs) than European-Americans (EAs). The aim of this study was to test for differences in the order of initiation of cannabis and alcohol use between AA and EA women and to determine whether order and ethnicity contribute independently to risk for rapid ...

OBJECTIVE Recent studies have suggested that cannabis use is a risk factor for developing schizophrenia. We tested the hypothesis that cannabis use increases the likelihood of psychosis-like experiences in non-clinical participants who scored highly on a measure of schizotypy. METHOD The psychological effects of cannabis were assessed in 137 healthy individuals (76% female, mean age 22 years)...

OBJECTIVE Numerous studies have found a robust association between cannabis use and the onset of psychosis. Nevertheless, the relationship between cannabis use and the onset of early (or, in retrospect, prodromal) symptoms of psychosis remains unclear. The study focused on investigating the relationship between cannabis use and early and high-risk symptoms in subjects at clinical high risk for ...

Cannabis users are more likely to have psychotic experiences (PEs). The degree to which these associations are driven by genetic or environmental influences in adolescence is unknown. This study estimated the genetic and environmental contributions to the relationship between cannabis use and PEs. Specific PEs were measured in a community-based twin sample (4,830 16-year-old pairs) using self-r...

BACKGROUND There are inconsistencies in findings as to whether cannabis use has a negative impact on clinical outcomes for people with established psychosis. Effects may be more evident on patients with recent onset psychosis. AIM To investigate the relationship between cannabis use and clinical outcome, including whether change in cannabis use affects psychotic symptoms, affective symptoms, ...

AIMS To examine changes in the evidence on the adverse health effects of cannabis since 1993. METHODS A comparison of the evidence in 1993 with the evidence and interpretation of the same health outcomes in 2013. RESULTS Research in the past 20 years has shown that driving while cannabis-impaired approximately doubles car crash risk and that around one in 10 regular cannabis users develop d...

BACKGROUND The marijuana plant cannabis is known to have therapeutic effects, including improvement of inflammatory processes. However, no report of patients using cannabis for Crohn's disease (CD) was ever published. OBJECTIVES To describe the effects of cannabis use in patients suffering from CD. METHODS In this retrospective observational study we examined disease activity, use of medica...

UNLABELLED Opioids are commonly used to treat patients with chronic pain (CP), though there is little evidence that they are effective for long term CP treatment. Previous studies reported strong associations between passage of medical cannabis laws and decrease in opioid overdose statewide. Our aim was to examine whether using medical cannabis for CP changed individual patterns of opioid use. ...