Policy and practice briefingsResponding to problems associated with cannabis use

Issues

Cannabis use can result in, or exacerbate, a range of physical and mental health, social and economic problems. Problems are more likely to develop if use begins at a young age and develops into regular and long-term use. The primary objectives for health and social responses to address cannabis use and associated problems should therefore include:

  • preventing use, or delaying its onset from adolescence until young adulthood;
  • preventing the escalation of cannabis use from occasional to regular use;
  • reducing harmful modes of use; and
  • providing interventions, including treatment, for people whose cannabis use has become problematic

Response options

  • Prevention programmes, such as multicomponent school interventions that develop social competences and refusal skills, healthy decision- making and coping, and correct normative misperceptions about drug use; family interventions; and structured computer-based interventions.
  • Brief interventions, for example, motivational interviewing delivered in emergency departments or primary care settings.
  • Treatment: research suggests that cognitive behavioural therapy, motivational interviewing and contingency management can reduce cannabis use and harm in the short term; multidimensional family therapy can help reduce use in high-severity young patients; and some web- and computer-based interventions can reduce cannabis use in the short term.
  • Harm reduction interventions, for example, addressing the harms associated with smoking cannabis, especially when used together with tobacco.

European picture

  • Universal prevention is widespread but not always evidence-based. Selective prevention approaches are used in some European countries, most commonly with young offenders or with youth in care institutions, but little is known about their effectiveness. Indicated prevention approaches and brief interventions do not appear to be widely used.
  • Many EU countries offer treatment for people with cannabis problems within generic drug treatment programmes, and cannabis-specific treatment is available in half of the countries. Most treatment is provided in community or outpatient settings and increasingly online.

Summary of the available evidence

Interventions to prevent or delay cannabis use

Response option Quality of evidence

Multicomponent interventions can reduce alcohol and cannabis use when delivered in schools using social influence approaches, correcting normative misperceptions and developing social competences and refusal skills. Programmes that only provide information about the risks of using drugs have not been found to be effective in preventing use.

moderate quality evidence

Universal family interventions, such as Familias Unidas, Focus on Kids, Strengthening Families 10–14, may be effective in preventing cannabis use when delivered across multiple settings and domains.

moderate quality evidence

Structured computer-based interventions may be effective in preventing cannabis use when delivered in schools or to family groups.

lower quality evidence

Motivational interviewing interventions targeting cannabis use may be effective when delivered in emergency departments or primary care settings.

lower quality evidence

It is unclear if school-based brief interventions can reduce substance use in young people although some information suggests they may possibly have some limited impact on cannabis use.

lower quality evidence

Key

  • speedometer at high High quality evidence — one or more up-to-date systematic reviews that include high-quality primary studies with consistent results. The evidence supports the use of the intervention within the context in which it was evaluated.
  • speedometer at medium Moderate quality evidence — one or more up-to-date reviews that include a number of primary studies of at least moderate quality with generally consistent results. The evidence suggests these interventions are likely to be useful in the context in which they have been evaluated but further evaluations are recommended.
  • speedometer at low Low quality evidence — where there are some high or moderate quality primary studies but no reviews available OR there are reviews giving inconsistent results. The evidence is currently limited, but what there is shows promise. This suggests these interventions may be worth considering, particularly in the context of extending services to address new or unmet needs, but should be evaluated.

Treating problematic cannabis use

Response option Quality of evidence

Behavioural interventions (e.g. cognitive behavioural therapy, motivational interviewing and contingency management) can reduce use and improve psychosocial functioning in adults and adolescents in the short term.

moderate quality evidence

Multidimensional family therapy helps reduce use and keep patients in treatment, especially in high- severity young patients.

moderate quality evidence

Web- and computer-based interventions may be effective in reducing cannabis use, at least in the short term, and are a cost-effective way of reaching a large number of cannabis users.

lower quality evidence

Key

  • speedometer at high High quality evidence — one or more up-to-date systematic reviews that include high-quality primary studies with consistent results. The evidence supports the use of the intervention within the context in which it was evaluated.
  • speedometer at medium Moderate quality evidence — one or more up-to-date reviews that include a number of primary studies of at least moderate quality with generally consistent results. The evidence suggests these interventions are likely to be useful in the context in which they have been evaluated but further evaluations are recommended.
  • speedometer at low Low quality evidence — where there are some high or moderate quality primary studies but no reviews available OR there are reviews giving inconsistent results. The evidence is currently limited, but what there is shows promise. This suggests these interventions may be worth considering, particularly in the context of extending services to address new or unmet needs, but should be evaluated.

Implications for policy and practice

Basics

  • Core responses in this area include general prevention approaches aimed at discouraging use or delaying onset, brief interventions for those with minor problems and formal treatment for those with more serious problems.

Opportunities

  • More attention should be paid to harm reduction approaches to cannabis use, particularly with respect to the patterns of use and co-use with tobacco.
  • Greater use of e-health approaches.
  • The new regulatory models for cannabis that are emerging globally can provide valuable information on the pros and cons of different options for regulation and their likely impact on responses to cannabis problems.

Gaps

  • There is still a need to develop a better understanding of the nature of cannabis-related disorders and what constitutes the most effective and appropriate treatment options for different clients.
  • A better understanding is needed of the types of treatment being received by the increasing numbers of people entering treatment for cannabis use in Europe, in order to ensure that provision is appropriate and efficient.

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