1. MAP recognises that cannabis is a widely used illicit psychoactive substance with many of those using cannabis doing so for ‘recreational’ purposes. Using a psychoactive substance cannot be regarded as a recreational activity especially when such activity exposes an individual to potential psychological addiction and other adverse consequences in physical, psychological and social domains.
2. Cannabis use commonly starts in adolescence, a crucial period for brain development.Adolescence is described as “the critical period of addiction vulnerability” because during this period the brain pathways that enable people to experience motivation and rewarding experiences are still developing. During this period adolescents are more prone to risk taking and less prone to impulse control (1). Since cannabis impacts the trajectory of brain development at such a sensitive stage there is a high potential for adverse effects. One of the main reasons is because crucial processes of brain development and synaptic pruning are ongoing (2); indeed, brain development and synaptic pruning continue up to the age of 25 (3).
3. Clinical and research evidence confirms the negative consequences in various domains of functioning consequent to cannabis use. Repeated exposure of the brain to a range of potent drugs results in dysfunction of its vital and decisive actions that tend to define human nature. It appears that, compared to older adults, the repercussions in those whose brains are still developing are more devastating.
4. Adolescents and young adults who are regular cannabis users manifest a range of cognitive deficits, including impairments in attention, learning and memory, and an inability to switch ideas or responses. These deficits are similar in adults, but in adolescents they are more likely to persist and may recover only after longer periods of abstinence. Adolescent onset cannabis users, show greater IQ decline than adult-onset cannabis users; impairment is still evident after cessation of use for 1 year or more (4).
5. Cannabis users at any age are at an increased risk of developing psychotic symptoms or schizophrenia-like psychotic illness; a recent meta analysis reported that the odds ratio for developing psychotic symptoms or a psychotic disorder in cannabis users versus non users reached 3.9 among the heaviest users (5). Furthermore, recently published research reports that adolescent cannabis use is associated with increased risk of psychosis, which risk is not attributable to family history of psychosis or other substance use (6).
6. Cannabis use in patients with schizophrenia is associated with poorer outcomes and more prominent negative symptoms. It is also a known fact that cannabis induced psychosis is a harder form of psychosis to treat and sometimes these people never fully recover (7).
Points for consideration:
1. In the USA, cannabis use in young people has increased since the mid 1990s; use of the drug is greater in those states that have legalised cannabis for medicinal or recreational purposes (8).
2. In the UK, where it has been decriminalised but not legalised, cannabis use has fallen; in 1996, 25.8% of 16 to 24 year olds admitted to having used cannabis in the previous year versus 16.4% in 2016 (9).
3. The current plan to legalise cannabis is likely to result in greater use; however, cannabis is not a harmless drug. Whilst it is a known fact that cannabis use is widespread it is also known that the fact that it is illegal probably hinders some individuals from purchasing the drug. If cannabis were to be legalised such barriers would be removed and there will be a surge in cannabis use. The increase in rate of cannabis use may even occur in the younger population for whom the drug will still be illegal.
4. The argument being employed by those in favour of legalisation of cannabis, is that legalisation will allow the buyers to choose the type and strength of cannabis they are purchasing. Literature from Canada, where cannabis is used for medical purposes, shows that users are experiencing adverse effects in physical and mental health domains. This illustrates the fact that, even in controlled quantities, cannabis remains harmful and its deleterious effects not sufficiently understood (10).
5. An important point to consider is that we cannot confidently declare that we know what the longer-term consequences of cannabis legalisation are. It might well be the case that, as what happened with alcohol and nicotine, a number of years down the line, the dimension of the adverse consequences upon individuals and society will become apparent. Arguably, one could predict that cannabis use will decrease in the longer term as it falls out of favour. (9).
1. In view of the published evidence to date that relates cannabis use on adverse mental health outcomes, MAP does not support the legalisation of non medical cannabis use in Malta. Notwithstanding, MAP does continue to support the decriminalisation of cannabis use.
2. MAP is concerned that there is a general public misconception about the consequences of cannabis use, at any age, but even more so in adolescents and young adults. MAP strongly recommends that a nationwide education campaign is carried out. Such an education campaign must not only target potential users but the population at large. Carers and educators need to be empowered to provide arguments based on scientific evidence to counter the perception that cannabis is a recreational and safe drug.
3. Encouraging young adults in Malta to engage in positive social activities such as organised sport and voluntary activities resonates more with the concept of recreation; rather than providing a legal route to accessing mind altering substances which in the long run may lead to a substance use disorder.
4. Research into this topic is ongoing; there is still much we do not know. We strongly recommend that policy makers and legislators allow themselves to be guided by emerging scientific evidence.
5. MAP is willing to continue discussing the topic with the relevant authorities as well as guide educational campaigns about this issue.
1. European Monitoring Centre for Drugs and Drug Addiction. Multidimensional family therapy for adolescent drug users: a systematic review. EMCDDA papers, Publication office of the European Union, 2014.
2. The health and social effects of non-medical cannabis use, World Health Organisation,2016.
3. Brain’s synaptic pruning continues into your 20’s; Zukermann and Purcell, New Scientist, August 2011.
4. Persistent cannabis users show neuropsychological decline from childhood to midlife, Meier et al, PNAS October, 2012.
5. Meta-Analysis of the association between the level of cannabis use and risk of psychosis,Marconi et al, Schizophrenia Bulletin, Volume 42, Issue 5, 1 September 2016.
6. Adolescent cannabis use, baseline prodromal symptoms and the risk of psychosis,Mustonen et al, BJPsych, Vol212, Issue 4, March 2018.
7. Cannabis use and progressive cortical thickness loss in areas rich in CB1 receptors during the first five years of schizophrenia; Rais et al, European Neuropsychopharmacology,December 2010.
8. US Adult Illicit Cannabis Use, Cannabis Use Disorder, and Medical Marijuana Laws:1991-1992 to 2012-2013; Hasin et al, JAMA Psychiatry, June 2017.
9. Cannabis and psychosis: what do we know and what should we do? Colizzi and Murray, BJPsych, Vol212, Issue 4, April 2018.
10. Research lacking on medical pot, ample evidence of harms: doctors’ groups; Geordon Omand, The Canadian Press, Posted: Dec 14, 2017.