Which biological and self-report measures of cannabis use predict cannabis dependency and acute psychotic-like effects?

H Valerie Curran, Chandni Hindocha, Celia J A Morgan, Natacha Shaban, Ravi K Das, Tom P Freeman

Research output: Contribution to journalArticle

11 Citations (Scopus)


BACKGROUND: Changes in cannabis regulation globally make it increasingly important to determine what predicts an individual's risk of experiencing adverse drug effects. Relevant studies have used diverse self-report measures of cannabis use, and few include multiple biological measures. Here we aimed to determine which biological and self-report measures of cannabis use predict cannabis dependency and acute psychotic-like symptoms.

METHOD: In a naturalistic study, 410 young cannabis users were assessed once when intoxicated with their own cannabis and once when drug-free in counterbalanced order. Biological measures of cannabinoids [(Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), cannabinol (CBN) and their metabolites)] were derived from three samples: each participant's own cannabis (THC, CBD), a sample of their hair (THC, THC-OH, THC-COOH, CBN, CBD) and their urine (THC-COOH/creatinine). Comprehensive self-report measures were also obtained. Self-reported and clinician-rated assessments were taken for cannabis dependency [Severity of Dependence Scale (SDS), DSM-IV-TR] and acute psychotic-like symptoms [Psychotomimetic State Inventory (PSI) and Brief Psychiatric Rating Scale (BPRS)].

RESULTS: Cannabis dependency was positively associated with days per month of cannabis use on both measures, and with urinary THC-COOH/creatinine for the SDS. Acute psychotic-like symptoms were positively associated with age of first cannabis use and negatively with urinary THC-COOH/creatinine; no predictors emerged for BPRS.

CONCLUSIONS: Levels of THC exposure are positively associated with both cannabis dependency and tolerance to the acute psychotic-like effects of cannabis. Combining urinary and self-report assessments (use frequency; age first used) enhances the measurement of cannabis use and its association with adverse outcomes.

Original languageEnglish
Pages (from-to)1574-1580
Number of pages7
JournalPsychological Medicine
Issue number9
Early online date4 Sep 2018
Publication statusPublished - 31 Jul 2019



  • Biological markers
  • cannabinoids
  • cannabis
  • predictors of dependence
  • predictors of psychotic-like
  • self-report measures

ASJC Scopus subject areas

  • Applied Psychology
  • Psychiatry and Mental health

Cite this