Heavy Cannabis Use, Dependence and the Brain

Although cannabis use disorder (CUD) is one of the most common substance use disorders (SUDs), the impact of CUD on the brain remains unclear and understudied.

In a recent article, published in Addiction journal, researchers from the University of Amsterdam and Ludwig Maximilan University have brought together the existing research on the relationship between heavy cannabis use, cannabis use disorder (CUD) and the brain.

The article provides an epidemiological overview, as well as a clinical commentary, including potential causal mechanisms, assessments, treatment and prognosis.

Summary of findings

  • Although causality is unclear, heavy and dependent cannabis use is consistently linked with a high prevalence of comorbid psychiatric disorders and learning and memory impairments
  • Abstinence after treatment is only achieved in a minority of cases
  • Treatment targeted at reduction in use appears have some success
  • Severity of CUD impact on the brain is influenced by age of onset, heaviness of use, CUD severity, the ratio of cannabinoids and severity of comorbid disorders.

Despite there being evidence that learning and memory impairments as a result of CUD seem to recover after a period of abstinence, the number of cases of people achieving abstinence remains low. The researchers call for further research in order to shape effective treatment interventions.

Citation
Kroon, E., Kuhns, L., Hoch, E., and Cousijn, J. ( 2020) Heavy cannabis use, dependence and the brain: a clinical perspective. Addiction, 115: 559– 572. https://doi.org/10.1111/add.14776.