Comprehensive Interventions for Reducing Cannabis Use

Judit Tirado-Muñoz; Juan I. Mestre-Pintó; Magí Farré; Francina Fonseca; Marta Torrens


Curr Opin Psychiatry. 2018;31(4):315-323. 

In This Article

Abstract and Introduction


Purpose of review: Cannabis is globally the most commonly cultivated, trafficked and consumed illicit drug of abuse. The current article provides an updated overview of existing comprehensive interventions for preventing and reducing cannabis use.

Recent findings: The PubMed database was searched for evidence regarding comprehensive interventions for preventing and reducing cannabis use from June 2016 to January 2018. The search resulted in 274 articles. Twenty-one studies were selected for assessment and 13 fulfilled the inclusion criteria. Six systematic reviews regarding preventive, psychosocial, pharmacological and risk reduction interventions were identified. Psychosocial interventions included therapist-assisted and computerized interventions. Four therapist-assisted, one computerized and two pharmacological clinical trials were published over the review period. Overall, considering the three different approaches (preventive, psychosocial or pharmacological) promising results have been found in certain interventions in reducing cannabis use among different types of users. In addition, recommendations to reduce adverse health outcomes related to cannabis use have also been reviewed.

Summary: Although relevant findings have been found so far, further research with adequately powered trials assessing comprehensive interventions for reducing cannabis use remains a need before definitive treatment recommendations can be established.


In Europe, around 23 million people (15–64 years old) report cannabis use in the past year.[1] In the United States, this prevalence significantly increased from 4.1% in 2002 to 9.5% 2013, and the prevalence of cannabis use disorder (CUD) increased from 1.5 to 2.9%.[2,3] Worldwide, marijuana use is extensive among adolescents and young adults,[4] with an estimation of around 17 million users.[1]

Cannabis consumption has been associated with short-term and long-term health effects.[5–7] Early-onset of cannabis use is associated with a large set of problems such as poorer cognitive performance, intelligence quotient decline, and later drug use and substance use disorders.[8,9]

Recent policy changes in certain countries worldwide have allowed deeper examination of the potential effects of decriminalization of cannabis use for medical purposes and in some cases for nonmedical purposes. Some have legalized the medical use of cannabis (Canada, Chile, Colombia, Croatia, Cyprus, Czech Republic, Jamaica, Finland, Germany, Greece, Israel, Italy, Macedonia, the Netherlands, Poland, Peru, Romania and Uruguay) while some others have legalized the use of specific cannabinoids only, such as Sativex (France and United Kingdom). Mexico and Switzerland limited the tetrahydrocannabinol (THC) content to 1% while in Uruguay, the Netherlands and Spain, cannabis can be obtained without need for a prescription. In the USA, marijuana is legal to some extent in 30 states in the USA, though the majority only allows consumption for medicinal purposes. Recreational use is allowed in Washington state, Oregon, Nevada, California, Colorado, Alaska, Maine, Massachusetts and Washington DC.

Scientific literature does not report increases in adolescent cannabis use after medical or recreational legalization. However, certain studies suggest that these recent changes in the regulatory framework may have driven the increase of cannabis potency, childhood exposure, adult cannabis use, CUD's, emergency room visits and vehicle crashes.[10,11]

Such scenario endorses the need to provide cannabis users and health systems with a wide-range of efficient treatment opportunities;[12] with the development and evaluation of comprehensive interventions for cannabis users becoming a challenge of crucial importance.

The current study aims to provide an updated overview of existing comprehensive interventions for reducing cannabis use; classified into preventive, psychosocial, pharmacological or comprehensive recommendations to reduce adverse health outcomes (risk-reduction approaches).