Non-medical cannabis use: international policies and outcomes overview. An outline for Portugal

Abstract Introduction Cannabis is probably the most commonly used illicit drug. It is often regarded as a relatively nonharmful experience, even though evidence indicates otherwise. Legalization of non-medical cannabis, which has already taken place in several countries, is currently a controversial issue. Objective To provide an up-to-date overview of current models and policies and their outcomes that can inform future political decisions regarding non-medical cannabis use. Methods PubMed/MEDLINE and Google Scholar scientific databases were searched for articles written in English, Spanish, and Portuguese published between 1990 and December 2020. The reference lists of these articles were similarly used as bibliography sources. Gray literature was also included. Results While non-medical cannabis has been decriminalized in many countries, it has only been legalized in Uruguay, Canada, and some U.S. states. Several benefits of legalization were identified: decreases in cannabis-related crimes, law-enforcement and judicial costs; reduction in synthetic cannabis supply; decline in black economies and possible diminution of other illegal drug buying; and tax revenue increases. Reported legalization problems included: increases in cannabis use; cannabis-related disorders; and cannabis-related accidents and hospitalizations. Harm-reduction strategies are available in the scientific literature. Conclusion Growing, although incomplete, evidence exists to guide policy makers, minimize cannabis-related harm, and positively contribute to public health, if the legalization path is to be followed. Dialogue between legislators and science should be encouraged. There are more than a few legalization pathways, with diverse economic, social and health wellbeing effects. Public health-driven, instead of profit-driven models, seem to offer the most benefits regarding non-medical cannabis legalization. Most of the true public health effects of cannabis legalization are still unknown, for we are still in the early stages of these policies and their implications. Future studies should address the medium-to-long-term social, economic, and health consequences of legalization policies.


Introduction
Cannabis is possibly the most widely-used illicit drug in the world. 1 Non-medical (commonly referred as "recreational") cannabis consumption is often regarded as a relatively non-harmful experience. 2 However, the risks of acute and chronic health impairments associated with cannabis use are well documented, 3 particularly mental health harm. 4 Its long-term use has also been associated with a host of deleterious mental health, developmental, and psychosocial outcomes. 5 Although it is difficult to establish a direct causal link between cannabis use and psychotic disorders, prospective, longitudinal, and epidemiological studies consistently report an association between cannabis usage and schizophrenia in which drug use precedes psychosis, controlling for other risks factors. [6][7][8][9] Not only may cannabis use play a role in the first psychotic episode, but its continued consumption is also associated with poorer prognosis and with increased relapse rates, even when controlling for other factors. 9,10 Particularly when used heavily (defined as "DSM-IV cannabis use disorder" or "at least weekly cannabis use"), cannabis may be associated with an increased risk of developing depressive disorders. 11 Adolescent cannabis use has been linked to increased risk of developing depression and suicidal behavior later in life, even in the absence of a premorbid condition. 12 Prenatal exposure to cannabis is also a matter of concern, as associations have been found with higher offspring psychopathology during middle childhood, sleep problems, lower cognition, lower gray and white matter volumes, lower total intracranial volume, and reduced birth weight, 13 as well as affective symptoms and ADHD. 14 A recent metaanalysis showed an association between cannabis use and violence when considering individuals with severe mental illnesses 3 and lifetime combustible cannabis use was associated with a 2.12 hazard ratio of developing tracheal, bronchus, or lung cancer over nonusers. 15 The acute intoxicating effects of use have been associated with a higher risk of motor vehicle collision [16][17][18] and marginally associated with severe and fatal injuries. 5 Recently, several countries have been discussing the possibility of legalizing largescale commercial cannabis production and sale of cannabis for nonmedical use, sometimes called recreational use, after others had already established decriminalization and depenalization policies.
Non-medical cannabis legalization is a controversial issue due to various moral, ethical, public health, legislative, and logistic issues associated with the matter. 19 Decriminalization differs from legalization in the sense that purchase, possession, and consumption of the drugs in question remain criminal offenses and are subject to criminal actions (e.g., small legal fines), although usually falling short of imprisonment. [20][21][22] Legalization, on the other hand, means that cannabis would be legally available for adults and allows governments to regulate its use and sale. [20][21][22][23] This review aims to provide an overview of current models and their outcomes that may help to inform future non-medical cannabis use policies. "Cannabis," "cannabis use," "marijuana," "cannabis legalization," "cannabis recreational use," "non-medical cannabis" AND "Netherlands," "Uruguay," "USA," "Canada," "Spain," "Portugal"; and "Portugal" AND "drug decriminalization law" OR "Portuguese drug law." Titles and abstracts were screened for inclusion according to their relevance to the paper's objectives. requiring periodic attendance at a designated place). 20,25 While the data on the outcomes of the Portuguese -Reduction of drug-related judicial costs. 28,30 Even though drug use is not legal in Portugal -but a social offence 20

Legalization of non-medical cannabis use
Cannabis legalization is not a binary option opposing commercial legalization to continuing prohibition, as it includes a variety of possible programs. [20][21][22][23][24][25]36,37 Several countries and states have abandoned the prohibitionist approach to drug use, and different regulation models have been adopted: Belgium, 20 there was more advertising than nowadays). 40 In Spain, possession and use in a public place is subject to administrative sanctions or fines. 20 However, people are allowed to grow their own cannabis, even though they cannot run private profiting cannabis enterprises. The first cannabis social club opened in Barcelona in 2001. 20 These clubs are non-profit and must follow recommendations regarding limits on monthly personal amounts of cannabis, hours of operation, and membership; promotion is banned. 20 Questions have been raised about this model since legal cannabis access is limited to people who grow it for personal use or are invited into a social club. 23 Therefore, some people may be forced to rely on black market sources. 23

United States
Oregon, Washington DC, and Colorado have commissions to control sellers' activities and sales to people under the age of 21 are prohibited. 23 Cannabisimpaired driving is banned. 23 Products' constituents and labels are state-controlled. 23 Promotion is permitted in Washington and Colorado (except to youth under the age of 21), 23 but not in Oregon. 24 In Colorado, an 80% decrease in law-enforcement and judicial costs related to cannabis was observed between 2010 and 2014 and overall expenses related to drug combat have reduced by 23% since 2010. 24 After the opening of cannabis stores in 2014, arrests associated with synthetic cannabis reduced significantly. 24 The reduction in synthetic cannabis supply is described as one of the benefits of legalization. 24  The increase in cannabis potency (meaning a higher tetrahydrocannabinol: cannabidiol ratio) was also observed in Washington, 24 and it is believed to be a consequence of investments in innovation, development and marketing of characteristic products with for-profit goals. 24,36 This is the case because Washington's and Colorado's legal frameworks allow the price of cannabis to be set by the market itself. 24,36 Although cannabis potency has been rising both in Europe and the United States, the increase has been more pronounced in the latter. 55 There are some concerns regarding the possible rise of "Big Cannabis" and its associated lobbying and marketing influence, 23 42 Adults are also allowed to make cannabis-infused food and drinks. 42 Each household is allowed to grow up to four cannabis plants from licensed seed or seedlings. 42 Each province sets its own procedures for retail sales, and these vary as to ownership or retail outlets (by the provincial government or private enterprise), but all include an option for on-line sales. 42 The economic impact of this policy has recently been studied. 57 The analysis of cash circulation pointed to the expected move of the majority of cannabis users from the black to the official economy. 57 Statistics Canada calculates that around one-quarter of the cannabis market remains illegal or even slightly less over time. 57

Strengths
We undertook an up-to-date and comprehensive review of cannabis legalization policies and their shortto-medium-term outcomes, attempting to impartially and equitably report and compare them. Working from this overview, we developed a scientificallydriven perspective on how to adequately apply these learnings to the Portuguese context and, possibly, in other nations.
While identifying and summarizing theory about the aforementioned topic, our study helps reinforce the foundations for development of more structured and prospective research on cannabis legalization, while at the same time identifying the research path to be followed.

Limitations
As a non-systematic literature review, our study is not free from biases such as authors' assumptions, nor is it replicable. Being a narrative review, our study may not include all the appropriate literature. The existence of bias due to political and social agendas behind the gray literature included cannot be ruled out.
Some differences found between the outcomes of policies may be due to the study methodology or a lack of studies or reports, and not to advantages of one strategy over the other (e.g., exposure of young children to cannabis products in the United States vs. no reference to them in Uruguay).

Conclusion
The legalization of non-medical cannabis issue is a hot political subject with as-yet uncertain public health outcomes and balancing its advantages and disadvantages is no easy task.