Examining the profile of high-potency cannabis and its association with severity of cannabis dependence.

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 were profiled and examined for possible associations between frequency of use and (i) cannabis dependence, (ii) cannabis-related concerns. RESULTS: Frequent use of high-potency cannabis predicted a greater severity of dependence [days of skunk use per month: b = 0.254, 95% confidence interval (CI) 0.161-0.357, p < 0.001] and this effect became stronger as age decreased (b = -0.006, 95% CI -0.010 to -0.002, p = 0.004). By contrast, use of low-potency cannabis was not associated with dependence (days of other grass use per month: b = 0.020, 95% CI -0.029 to 0.070, p = 0.436; days of resin use per month: b = 0.025, 95% CI -0.019 to 0.067, p = 0.245). Frequency of cannabis use (all types) did not predict severity of cannabis-related concerns. High-potency cannabis was clearly distinct from low-potency varieties by its marked effects on memory and paranoia. It also produced the best high, was preferred, and most available. CONCLUSIONS: High-potency cannabis use is associated with an increased severity of dependence, especially in young people. Its profile is strongly defined by negative effects (memory, paranoia), but also positive characteristics (best high, preferred type), which may be important when considering clinical or public health interventions focusing on cannabis potency.

Lithium carbonate in the management of cannabis withdrawal in humans: an open-label study.

Cannabis is the most widely used illicit substance in the world. Estimates suggest that approximately 10-20% of cannabis users meet criteria for cannabis dependence and a significant proportion experience withdrawal discomfort on cessation of use. To date, there has been an absence of any clinically validated treatments to manage withdrawal. The current study is an open-label trial exploring the utility of lithium carbonate for the management of cannabis withdrawal symptoms in treatment seeking adult humans. In total, 20 participants were recruited to the study (19 men). All met DSM-IV cannabis-dependence criteria and had been smoking cannabis daily or almost daily for a mean 9 years. Participants were admitted to an inpatient detoxification facility and prescribed lithium 500 mg b.d. for 7 days. Cannabis withdrawal was assessed daily with the Marijuana Withdrawal Checklist (MWC). Two participants were withdrawn from the trial because of possible adverse effects. Sixty percent of participants completed the 7-day treatment program. Follow-up was conducted at a mean of 107 days following treatment. The mean percentage of days abstinent in the period between treatment cessation and follow-up was 87.57%. Twenty-nine percent of participants (n=5) reported continuous abstinence that was biochemically verified at follow-up. Agreement between self-reported cannabis use and urinalysis at follow-up was moderate (kappa=0.47). Significant reductions in symptoms of depression and anxiety and cannabis-related problems were also reported. This study provides evidence for the potential clinical utility and safety of lithium in the management of cannabis withdrawal. A randomised, placebo-controlled trial is recommended.