title: Examining the profile of high-potency cannabis and its association with severity of cannabis dependence.
abstract: 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.
  
  
  METHODS
  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.
authors.affiliation: Clinical Psychopharmacology Unit,University College London,London,UK.
authors.forename: T P
authors.initials: TP
authors.lastname: Freeman
authors.affiliation: Institute of Psychiatry,King's College London,Camberwell,UK.
authors.forename: A R
authors.initials: AR
authors.lastname: Winstock
mesh_terms: D000328:Adult; D002188:Cannabis / Q000009:adverse effects* / Q000145:classification; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000145:classification / Q000453:epidemiology*; D028321:Plant Preparations / Q000009:adverse effects* / Q000145:classification; D012720:Severity of Illness Index; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult
chemical_list: D028321:Plant Preparations
keywords: Addiction; cannabidiol; cannabis; delta-9-tetrahydrocannabinol; dependence; marijuana