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Background and Objective: An increasing number of countries are deciding to regulate the medicinal and/or recreational use of cannabis (Cannabis sativa L.). However, there is a lack of information on the impact of regular consumption of this substance on public health. In this study, for the first time, regular cannabis consumers in Spain were assessed using health indicators, comparing these data with the general population.

Methods: Various items of the Enquesta de Salut de Catalunya (ESCA) and other items related to cannabis use were selected to build a survey and administer it to a representative sample of regular cannabis users in Catalonia.

Results: Most of the indicators did not show any deterioration in the health of regular cannabis users compared with the general population. It was observed that users suffered from more sleep problems and about 40% of the sample would like to discontinue cannabis use, suggesting a dependence pattern. About 30% of the sample was able to discontinue the use of prescription medications because of cannabis. Social support and sleep problems, and not cannabis use, were predictors of depression and well-being scores.

Conclusions: It seems that regular cannabis use, despite contributing to problems related to sleep quality or dependence, does not have a negative impact on public health in a manner detectable using health indicators.


Cannabis sativa L. (cannabis) is a plant belonging to the Cannabaceae family. It is one of the world’s oldest cultivated plants and there is evidence supporting its medicinal, ritualistic, and social use in Europe and East Asia from 8,000 BCE.1 Despite its long history of use, the U.S. Drug Enforcement Agency classified cannabis as a Schedule I controlled substance with a high risk of misuse under the Comprehensive Drug Abuse Prevention and Control Act of 1970.

In 1961, cannabis was included in Schedules I and IV in the Convention on Narcotic Drugs, although in 2020, it was removed from Schedule IV in light of recognition of its medicinal properties. In recent years, the use of cannabis and cannabis-derived products has been regulated by countries such as Canada, Malta, and Uruguay, as well as several U.S. states.2–5 Other EU countries, such as Germany and Luxembourg, have announced their intention to regulate cannabis use by 2022.

Spain is the third European country, after Portugal and Luxembourg, in terms of the prevalence rate of almost daily cannabis consumption at 3.7% of the population.6 In addition, according to the Spanish national survey on the use of alcohol and other drugs (Encuesta sobre el Alcohol y otras Drogas en España) for 2019–2020, Catalonia is the third autonomous community (after the Balearic Islands and Murcia) in terms of the prevalence of usual cannabis users, with 10.9% of the population having consumed cannabis in the previous 30 days.7

In Spain, cannabis provision and consumption are possible through cannabis social clubs (CSCs), which are particularly common in Catalonia.8 However, it is still a prosecuted substance throughout the country. Nevertheless, the subcommittee on Health in the Spanish Parliament recently approved the regulation of the medical use of cannabis, while two political parties have presented bills to legalize the medical and recreational use of cannabis.9

Many studies have assessed both risks and therapeutic possibilities of cannabis use.10–13 However, there are some limitations to this approach. Although valuable from a pharmacological point of view, clinical trials are limited in terms of their external validity, as occurs in other research areas.14 Furthermore, clinical trials are designed to assess the therapeutic properties of cannabis and/or cannabinoids, while a recreational pattern of use might be quite different from that employed in such trials. Thus, it is challenging to extrapolate laboratory findings to the real world.

On the other hand, several observational studies reported the health effects of regular cannabis use in different countries.15–17 However, certain analyses of such studies conducted in the United States claimed that they are biased as they are focused on describing adverse effects rather than benefits.18 Furthermore, there are concerns regarding the ability of respondents to express their own health status in psychometric questionnaires due to subjects’ notable lack of ability to assess themselves accurately.19–21

Beyond clinical trials, an additional kind of observational study is the one using health indicators to assess health measures. These indicators are considered reliable objective measures that inform about a population’s health. Advantages include the ability to compare between populations from different countries and cultures. For instance, they are commonly used by several governments as a measure of public health.22 Although studies have used health indicators to assess cannabis users,23–25 to the best of our knowledge, this is the first study of its kind to focus on the Spanish population.

This research is especially timely given the current political atmosphere and the potential development of cannabis regulation in Spain.9



There are 600,000 regular cannabis users (consumption during the last 30 days) in Catalonia, as reflected in population surveys collected during the same year that we launched the survey of our study (2019–2020).7 Accordingly, the sample size of our study was calculated through an online calculator ( To obtain a 95% confidence interval, a sample of 384 subjects was needed: 125 men from 15 to 34 years of age, 132 men from 35 to 64 years, 63 women from 15 to 34 years, and 64 women from 35 to 64 years.

The inclusion criteria required subjects to be between 15 and 64 years of age; to reside in Catalonia; to have consumed cannabis in the previous 30 days; and to read, understand, and sign the informed consent form. The exclusion criteria were age below 15 or above 64 years, not residing in Catalonia, not having used cannabis during the previous 30 days, or not having understood or signed the informed consent form.


A questionnaire was developed specifically for this study. Forty-six items were selected from the Catalan public health survey [Enquesta de Salut de Catalunya (ESCA)]26 concerning the following areas: sociodemographic data, general health, lifestyle, use of alcohol and tobacco, social support (measured with the OSLO-3 questionnaire,27 listed in the European Core Health Indicators), psychological well-being [measured with the Warwick–Edinburgh Mental Well-being Scale (WEMWBS),28 Catalan validated version,29 a questionnaire used in several European health surveys30,31], depression (measured by the eight-item Patient Health Questionnaire depression scale [PHQ-8] questionnaire,32 a questionnaire used in the European Health Interview Survey33), and the use of medicines and health services.

The use of cannabis and other drugs, as well as cannabis-related experiences, was assessed using a modified version of the Cannabis Experience Questionnaire, which asks questions regarding having experienced fear, fear of becoming mad, anxiety, suspiciousness, happiness, feeling full of ideas, hearing voices, having a better understanding of the world, having visions, feeling unwilling to do anything, slowed thinking, difficulty concentrating, and difficulty thinking during cannabis consumption. Subjects were asked to also inform about their own assessment of these experiences (whether they were felt that these were positive, negative, or neutral experiences).34


From November 2019 to March 2022, sample recruitment was carried out within the Catalan territory. Most of the volunteers were recruited from CSCs that freely collaborated with the study authors. The surveys were self-administered in the presence of a researcher. Due to the outbreak of the COVID-19 pandemic, an online version of the survey was developed and disseminated through the International Center for Ethnobotanical Education, Research, and Service digital communication office using a snowball method.

Statistical analysis

Descriptive statistics were used to present the data. Then, data regarding health indicators were compared with Catalan normative data from the ESCA 2021. Two linear regression models were developed to assess which variables could better predict the psychological well-being of the sample, measured by the WEMWBS questionnaire, and levels of depression, measured by the PHQ-8 questionnaire. Student’s t-test was performed to determine differences in terms of age strata.

A p-value of <0.05 was considered statistically significant for both analyses. The IBM® SPSS, version 21.0, software package was used.


This study was approved by the Research Ethics Committee of the Universidad Autónoma de Madrid (Autonomous University of Madrid), Spain. Written informed consent was obtained from all volunteers. All experimental procedures were performed in accordance with relevant guidelines and regulations.


A total sample of 419 individuals was recruited. The mean age was 33.2 years (SD=10.4). The same age/gender strata that were used in the ESCA were followed, involving 156 men between 15 and 34 years of age, 118 men between 35 and 64 years, 87 women between 15 and 34 years, and 58 women between 35 and 64 years. Most participants were working in service positions (124; 29.8%), followed by trade jobs (85; 20.4%) and administrative jobs (59; 14.2%).

Regarding the education level, the majority of the sample had completed postcompulsory studies (171; 41.1%) or college (101; 24.3%). Regarding employment status, 313 subjects (72.2%) were working, while 36 subjects (8.7%) were studying and 25 (6%) were not working.

The drug use of the sample, apart from cannabis, consisted of experiences with 3,4-methylenedioxymethamphetamine (MDMA) (60.3%), cocaine (56.7%), lysergic acid diethylamide, psilocybin mushrooms or other psychedelics (51.4%), amphetamine (40.2%), and ketamine (22.5%).

Comparison with the general population

Regarding sociodemographic profiles, the percentage of subjects who completed postcompulsory studies (41.1%) or college (24.3%) in our sample was similar to that for those who completed higher education in the general population (⁓30%).35 About working status, 77% of the Catalan general population aged between 25 and 34 years (the most abundant age group within our sample) is employed, very similar to the percentage of employed subjects in our sample (72.2%).36

Users of cannabis showed better scores on the indicators for positive perception of health, BMI, cholesterol/blood pressure issues, presence of chronic diseases, and physical limitations in day-to-day activities. Lifestyle indicators were similar in terms of physical activity (walking daily for at least 10 min and time remaining seated daily). Concerning nutrition, cannabis users reported eating slightly more vegetables, whereas the general population eats slightly more fruits.

There was a notable difference regarding the main means of transport used as the bicycle is preferred by cannabis users, whereas the general population prefers their own vehicle (car or motorcycle). Finally, there were more sleep problems among cannabis users than in the general population (Table 1).

 Cannabis usersGeneral populationa
Health indicators  
 Positive perception of health88.2%81.5%
 Normal BMIb67.06%42.2%
 Cholesterol/blood pressure problems7.5%18.3%
 Presence of chronic disease21.2%55.1%
 Physical limitations in day-to-day activities14.4%21.3%
Lifestyle indicators  
 Walking 10 min everyday75.5%70.2%
 Time spent seated daily366 min330 min
 Taking more than 2 daily portions of vegetables22.8%14.7%
 Taking more than 2 daily portions of fruits14%17.4%
 Usual means of transportBicycle (36.5%)Own vehicle (56.1%)
 Presence of sleep problems37%18.9%

aOnly data from people aged between 15 and 64 years were retrieved for the general population.

bThe criterion for normal BMI was the same as that used by the ESCA=≥18 and <25.

ESCA, Enquesta de Salut de Catalunya.

In terms of social support, 89.4% of the sample of cannabis users showed intermediate or high social support, while 92.8% of the general population showed intermediate or high social support. Regarding the depression score, as measured by the PHQ-8 questionnaire, 92.9% of cannabis users did not have depression, while in the general population, this group constituted 79.5% of subjects. The score obtained for psychological well-being by cannabis users was 25.8, while in the general population, the score was 29.7 (Table 2).

 Cannabis usersGeneral populationa
Social support (intermediate–high)89.4%92.8%
Depression (absence)92.9%79.5%
Psychological well-being25.829.7

aOnly data from people aged between 15 and 64 years were retrieved for the general population.

Among the sample of cannabis users, 64.7% were smoking cigarettes, while in the general population, we find that 22.7% are smokers. Regarding alcohol consumption, cannabis users reported consuming a weekly mean of 0.7 units of beer/wine per day, whereas the general population consumes 1.4 daily units of beer.

Use of medicines and health services

The public Catalan health service (Servei Català de la Salut, CatSalut) was the most visited health service (51.4%). After pharmacies (48.6%), the most used services were dentistry (28.8%), specialized medicine (27.6%), and general medicine (25.2%). Among the sample, 28.1% had been prescribed one or more medications. The most common were nonsteroidal anti-inflammatory drugs, paracetamol, or metamizole (17.1%), followed by benzodiazepines (6.8%), omeprazole (1.9%), and antidepressants (1.7%).

Among the sample, 25.2% stated that they reduced their number of visits to health services due to cannabis use, while 31.7% of the sample reduced their use of prescription medicines due to cannabis consumption.

Use of cannabis

Regarding the use of cannabis, the majority of subjects (75.2%) used cannabis on a daily basis or more than once per week (19%). The amount of cannabis used daily was 1.18 g (SD=1.37), with subjects spending on a weekly basis between 10 and 30 euros (34.4% of the sample), <10 euros (28.7%), and between 30 and 50 euros (21.3%). Smoking cigarettes of cannabis mixed with tobacco was the main consumption method (85.3%), followed by cigarettes with only cannabis (8.7%), and using vaporizers (2.6%).

Among the sample, 16.5% reported that cannabis use affected their health negatively. Additionally, more than one-third of the sample (37.3%) reported that they would like to interrupt their cannabis use.

Cannabis-related experiences

Summarized in Table 3 are the frequencies and assessments of different experiences that occurred during cannabis use. As is evident, subjects reported myriad experiences, both positive (happiness, full of ideas, and better understanding of the world) and negative (anxious, slowed thinking, and concentration difficulties).

Experiences during consumptionSeldom or neverOccasionally or oftenMost of the time or almost alwaysAssessment of the experience
Fear of becoming mad90.1%8.6%0.2%28%42.1%29.9%
Full of ideas4.6%60.9%34.5%91.8%7.4%0.8%
Hearing voices96.6%2.2%0.2%24.8%49.3%25.8%
Better understanding of the world15.3%56.3%28.4%81.2%17.5%1.4%
Having visions92.4%6.6%0.7%33.9%48.6%17.5%
Unwilling to do anything21%72.2%6.8%30.7%39.5%29.8%
Slowed thinking24.9%71.2%3.8%18.1%44.3%37.6%
Concentration difficulty28.1%65.7%6.3%15.4%42%42.6%
Thinking difficulty46.3%521.6%15.9%44.5%39.5%

Linear regression models

The linear regression model revealed that when the education level [F(13, 378)=9.71, p=0.02, R2=0.25], the number of days per week one walked for more than 10 min [F(13, 378)=9.71, p=0.02, R2=0.25], and social support [F(13, 378)=9.71, p<0.001, R2=0.25] were lower, depression scores (PHQ-8) were higher. In contrast, as the presence of chronic illness [F(13, 378)=9.71, p=0.002, R2=0.25], difficulty sleeping [F(13, 378)=9.71, p<0.001, R2=0.25], and economic difficulties [F(13, 378)=9.71, p=0.01, R2=0.25] increased, depression scores also increased.

With regard to well-being (WEMWBS), it was observed that the presence of chronic illnesses [F(13, 381)=6.74, p=0.02, R2=0.18] and sleep problems [F(13, 381)=6.74, p<0.001, R2=0.18] predicted lower BP1 scores. Finally, higher social support scores [F(13, 381)=6.74, p<0.001, R2=0.18] predicted a higher well-being score.

Differences between age groups

Student’s t-test showed no differences in general health status, well-being, or social support between age strata. However, subjects aged 15 to 34 years scored worse than people aged 35 to 64 years on the WEMWBS.


This article presents the results of an assessment of a representative sample of the current Catalan population using cannabis through the use of public health indicators. This research has not previously been carried out within the Spanish territory, and it should be used not only by researchers but also politicians and stakeholders to design and implement evidence-based public policies, especially in this moment when there is an open debate on cannabis legalization in Spain.

The study sample reported higher drug use than the general population as 60.3% of the sample had tried MDMA (6.4% in the general population), 56.7% had tried cocaine (13.6% in the general population), and 51.4% had tried hallucinogens (7.6% in the general population).37 However, this higher use does not seem to be associated with harmful effects on health, as reflected in the indicators used. These results are relevant given the long-debated potential role of cannabis as a “gateway drug.”38 This hypothesis states that drugs such as tobacco, alcohol, and cannabis could serve as gateways to drugs such as cocaine and heroin.

Nevertheless, it should be noted that progression from cannabis to other illicit drugs remains largely unknown.39 In fact, a recent report by the Department of Justice of the United States concluded, “The existing statistical research and analysis show mixed results and do not clearly demonstrate scientific support for cannabis use leading to harder illicit drug use.”40 In any case, it seems clear that users of cannabis have much higher rates of using other illicit drugs,41,42 although it is challenging to elucidate an ultimate explanation for that phenomenon. In that regard, a platform from civil society (the Drug Policy Alliance) suggested, “[…] people who have used other drugs are more likely to have also used marijuana. Not the other way around.”43

When comparing our sample with data obtained from the general population using the ESCA, it was found that cannabis users had better indicators regarding the positive perception of health, BMI, cholesterol/blood pressure issues, presence of chronic diseases, physical limitations in day-to-day activities, means of transport (as the bicycle was preferred by cannabis users), and depression.

While these differences cannot be attributed solely to cannabis use, it suggests that regular users of this drug are not experiencing relevant harmful effects in terms of fundamental indicators of overall health. We must remember that assessing the specific impact of cannabis use on health is challenging as health is a highly complex construct affected by several variables.

Our group has experience in conducting health assessments among other drug users. For instance, in the case of ayahuasca, we performed epidemiological studies in various countries to assess regular ayahuasca ceremony participants using health indicators.44,45 In those studies, ayahuasca users also scored better than the general population on several health indicators.

However, we prefer to interpret the results in a complex manner, assuming that ayahuasca use was one self-care practice among others that can strengthen one’s lifestyle and positively impact health, instead of focusing exclusively on the substance itself. In this case, we suggest adopting a similar approach. Instead of assuming that cannabis use might have certain benefits that are suggested here, it could be hypothesized that certain lifestyle and health behaviors (including cannabis use) that subjects engage in lead to better general health.

Beyond this complex approach, there are studies that have tried to establish causal relationships between cannabis use and health outcomes. In that regard, a report by the World Health Organization stated that long-term cannabis use seems to produce psychiatric symptoms, including depressive symptoms (contradicting the present results), and symptoms of chronic and acute bronchitis, as well as microscopic injury to bronchial lining cells, but it does not produce chronic obstructive pulmonary disease. Long-term cannabis use can also trigger myocardial infarction and stroke, among other issues.46

Cannabis users also reported more sleep problems than the general population. This finding diverges from the improvements in sleep commonly reported by cannabis users with insomnia or chronic disorders.47–49 The relationship between sleep and cannabis use should be clarified since its use by a healthy population in a chronic manner might be detrimental, as some studies also suggest.50 Furthermore, in our sample, 16.5% of subjects reported that cannabis affected their health negatively. Thus, even among regular users of this substance, some experience adverse events that need to be addressed in future studies.

Remarkably, 25.2% of the sample reduced their number of visits to health services and 31.7% reduced their use of prescription medicines due to their cannabis use. This finding has also been reported regarding different populations of cannabis users51–54 and it is highly relevant given the potential health improvements related to reduced use of medicines as well as associated savings in terms of public health expenditure.

Regarding patterns of cannabis use, most of the sample smoked it in a cigarette/joint, mixed with tobacco. This might be the main cause of the abovementioned adverse pulmonary events found in long-term users.46 Indeed, mixing cannabis with tobacco may increase the risk of cancer and other respiratory diseases, but it is not yet clear whether cannabis users have a higher risk compared with tobacco users.46 This suggests that fundamental harm reduction strategies, such as using other consumption methods, should be promoted among regular cannabis users.

Interestingly, 37.3% of our sample expressed a desire to interrupt their cannabis use, suggesting a pattern of drug dependence. The cannabis withdrawal syndrome is well described,46,55 so it is plausible that those subjects felt that they cannot stop their cannabis use, although they want to. It should be noted that among recreational users, the chance of becoming dependent on cannabis after lifetime exposure is 8.9%, in contrast to 20.9% in the case of cocaine and 67.5% for tobacco.56

However, the prevalence of cannabis use and demands for treatment of cannabis use disorder have increased in the last decade.6 For this study, regular long-term users of cannabis were recruited, so it is expected that among these users, there was a high percentage of those who developed cannabis dependence. In relation to this and as can be seen from the results of the Cannabis Experiences Questionnaire (CEQ), subjects generally described positive experiences with cannabis, so the fact that nearly 40% of the subjects wanted to stop using cannabis is probably less associated with acute events and more so with longer-term consequences such as perceived dependence.

In addition, it should be noted that 37.3% may be an underestimate as answering positively to this question requires cannabis users to recognize that their use is causing a problem for them or others. Regarding psychological disorders, contrary to what is usually found in studies focused on assessing potential harms, the figures for depression and well-being were quite similar in our sample compared with the general population. Another hypothesis is that subjects of our sample were experiencing other harms or discomfort not captured by the survey.

The results from the CEQ are of special interest in terms of understanding why people maintain regular cannabis use. Biological theories reduce the complex experience of using cannabis regularly to a simple process, whereby the brain is supposedly hijacked through artificial activation of its reward system.57Table 3 shows how the cannabis experience is quite complex as both positive and negative experiences tend to coexist.

Feelings of happiness may appear alongside feeling suspicious and low motivation may occur alongside being full of ideas and having a better understanding of the world. Although the biological hypothesis regarding addiction suggests that people continue using cannabis after having negative experiences because their brain is hijacked, evidence suggests that 75% of subjects withdraw from drug use without the need of any medical or psychological treatment.58

The percentage of people who recover from a substance use disorder is about 90% (excluding tobacco use, which is about 80%).59,60 Therefore, perhaps the motivation to use cannabis may be more related to the perceived benefits that subjects obtain, which compensate for the negative aspects. It seems that most cannabis users (as is also the case with hallucinogen users61) learn to navigate the difficult experiences and/or assume that those negative effects are part of the experience without there being further detrimental consequences.

Findings from the linear regression models should be emphasized as they reinforce our complex approach, previously discussed, to the impact of substances on health. In the first model, the variables that strongly predicted the depression score were social support, the presence of chronic illnesses, and difficulty sleeping, among others, which although statistically significant, were not as strongly related. Note that both social support and sleep problems are variable and highly related to symptoms of depression.62 Similarly, sleep problems and social support were strong predictors of well-being. This clearly suggests how the complex construct of health is affected by variables that extend beyond physical indicators, such as social support.

It is intriguing that considering the observed relevance of sleep problems in these analyses for the measures of depression and well-being, cannabis users scored better than the general population on these measures, even when reporting more sleep problems. Thus, those sleep problems might not be sufficiently severe so as to cause detrimental effects. It is noteworthy that in another study performed by our group with Spanish inmates who were using cannabis in prison, social support was also a strong predictor of health status.63

In the linear regression models performed in this study, the use of alcohol, living in an urban/rural area, and frequency of cannabis use were among the variables included, so it can be clearly seen how the use of specific substances might have only marginal effects on the overall health of subjects. Thus, these findings should encourage researchers assessing health status to not overly focus on the use of isolated substances, but rather try to establish causal relationships and explore complex variables, such as social support, given their relevance.

This study has some limitations that should be highlighted. Although the sample recruited is representative of cannabis users in Catalonia, it might not be representative of the overall general population with which it has been compared. For instance, the sample was provided mainly from Barcelona and therefore rural areas of Catalonia might not be well represented. The health indicators used are especially designed to allow comparisons even between populations from different countries, so they should not be much affected by these differences.

However, this potential limitation must be taken into account when interpreting the results. Additionally, some participants answered the survey during the COVID-19 pandemic, whereas the data from the general population were collected before the pandemic, and therefore the social context might have influenced the analyses performed. Another relevant limitation is not having collected further information about aspects such as the reasons for which a high percentage of users (37.7%) wanted to interrupt their cannabis use.

These aspects could inform more specifically about the risks of long-term and sustained use of cannabis. It is worth noting the limitations associated with working with self-reported data. The validity of self-reported measures has been questioned, arguing that researchers assume that subjects have an appropriate level of introspection and self-knowledge and that they are being honest.19–21


In this study, long-term users of cannabis scored in a similar way as the general population on a list of health indicators. These results were obtained using validated health indicators, especially designed and used by several governments to assess population health and compare this information between countries or specific populations. There was only one indicator associated with poorer health among cannabis users: sleep problems.

Additionally, potential dependence was also observed, suggesting that sustained use of cannabis for years might be associated with a higher risk of developing such dependence. Another significant result is that the frequency of cannabis use is seemingly unrelated to depression and well-being scores, whereas social support and sleep problems are strong predictors.

In conclusion, these findings suggest that long-term cannabis use might not play a central role in terms of public health, while other health behaviors and complex variables are more related to health. We suggest inclusion of cannabis-related items in national surveys of health as they would provide valuable data to support the progress of public debates regarding its regulation.


Thanks to Fundación Canna for helping to fund the study.

Author Disclosure Statement

The authors declare that there are no conflicts of interest.

Funding Information

No funding has been received for conducting this research.


  • 1. Long T, Wagner M, Demske D, et al. Cannabis in Eurasia: Origin of human use and Bronze Age trans-continental connections. Veg Hist Achaeobot 2016;25:1–14; doi: 10.1007/s00334-016-0579-6 CrossrefGoogle Scholar
  • 2. Adams PJ, Rychert M, Wilkins C. Policy influence and the legalized cannabis industry: Learnings from other addictive consumption industries. Addiction 2021;116(11):2939–2946; doi: 10.1111/add.15483 Crossref, MedlineGoogle Scholar
  • 3. Queirolo R, Boidi MF, Cruz JM. Cannabis clubs in Uruguay: The challenges of regulation. Int J Drug Policy 2016;34:41–48; doi: 10.1016/j.drugpo.2016.05.015 Crossref, MedlineGoogle Scholar
  • 4. Shanahan M, Cyrenne P. Cannabis policies in Canada: How will we know which is best? Int J Drug Policy 2021;91:102556; doi: 10.1016/j.drugpo.2019.09.004 Crossref, MedlineGoogle Scholar
  • 5. Shover CL, Humphreys K. Six policy lessons relevant to cannabis legalization. Am J Drug Alcohol Abuse 2019;45(6):698–706; doi: 10.1080/00952990.2019.1569669 Crossref, MedlineGoogle Scholar
  • 6. Manthey J, Freeman TP, Kilian C, et al. Public health monitoring of cannabis use in Europe: Prevalence of use, cannabis potency, and treatment rates. Lancet Reg Health Eur 2021;10:100227; doi: 10.1016/j.lanepe.2021.100227 Crossref, MedlineGoogle Scholar
  • 7. Ministerio de Sanidad, Plan Nacional sobre Drogas. Encuesta sobre alcohol y otras drogas en España, EDADES (2019–2020). Spain. Available from: [Last accessed: June 07, 2022]. Google Scholar
  • 8. Pardal M, Decorte T, Bone M, et al. Mapping cannabis social clubs in Europe. Eur J Criminol 2020;19(5):1477370820941392; doi: 10.1177/1477370820941392 CrossrefGoogle Scholar
  • 9. International Center for Ethnobotanical Education, Research and Services (ICEERS). ICEERS participates in the congressional subcommittee on cannabis, Barcelona, Spain. Available from: [Last accessed: June 07, 2022]. Google Scholar
  • 10. Kosiba JD, Maisto SA, Ditre JW. Patient-reported use of medical cannabis for pain, anxiety, and depression symptoms: Systematic review and meta-analysis. Soc Sci Med 2019;233:181–192; doi: 10.1016/j.socscimed.2019.06.005 Crossref, MedlineGoogle Scholar
  • 11. Marconi A, Di Forti M, Lewis CM, et al. Meta-analysis of the association between the level of cannabis use and risk of psychosis. Schizophr Bull 2016;42(5):1262–1269; doi: 10.1093/schbul/sbw003 Crossref, MedlineGoogle Scholar
  • 12. Datta S, Ramamurthy PC, Anand U, et al. Wonder or evil?: Multifaceted health hazards and health benefits of Cannabis sativa and its phytochemicals. Saudi J Biol Sci 2021;28(12):7290–7313; doi: 10.1016/j.sjbs.2021.08.036 Crossref, MedlineGoogle Scholar
  • 13. Kumar P, Mahato DK, Kamle M, et al. Pharmacological properties, therapeutic potential, and legal status of Cannabis sativa L.: An overview. Phytother Res 2021;35(11):6010–6029; doi: 10.1002/ptr.7213 Crossref, MedlineGoogle Scholar
  • 14. Rothwell PM. External validity of randomised controlled trials: “To whom do the results of this trial apply?” Lancet 2005;365(9453):82–93; doi: 10.1016/S0140-6736(04)17670-8 Crossref, MedlineGoogle Scholar
  • 15. Bar-Sela G, Vorobeichik M, Drawsheh S, et al. The medical necessity for medicinal cannabis: Prospective, observational study evaluating the treatment in cancer patients on supportive or palliative care. Evid Based Complement Alternat Med 2013;2013:510392; doi: 10.1155/2013/510392 Crossref, MedlineGoogle Scholar
  • 16. Walsh Z, Callaway R, Belle-Isle L, et al. Cannabis for therapeutic purposes: Patient characteristics, access, and reasons for use. Int J Drug Policy 2013;24(6):511–516; doi: 10.1016/j.drugpo.2013.08.010 Crossref, MedlineGoogle Scholar
  • 17. Swift W, Gates P, Dillon P. Survey of Australians using cannabis for medical purposes. Harm Reduct J 2005;2:18; doi: 10.1186/1477-7517-2-18 Crossref, MedlineGoogle Scholar
  • 18. O’Grady C. Cannabis research database shows how U.S. funding focuses on harms of the drug. Science; 2020. Available from: [Last accessed: June 08, 2022]. Google Scholar
  • 19. Devaux M, Sassi F. Social disparities in hazardous alcohol use: Self-report bias may lead to incorrect estimates. Eur J Public Health 2016;26(1):129–134; doi: 10.1093/eurpub/ckv190 Crossref, MedlineGoogle Scholar
  • 20. Prince SA, Adamo KB, Hamel ME, et al. A comparison of direct versus self-report measures for assessing physical activity in adults: A systematic review. Int J Behav Nutr Phys Act 2008;5:56; doi: 10.1186/1479-5868-5-56 Crossref, MedlineGoogle Scholar
  • 21. Haeffel GJ, Howard GS. Self-report: Psychology’s four-letter word. Am J Psychol 2010;123(2):181–188; doi: 10.5406/amerjpsyc.123.2.0181 Crossref, MedlineGoogle Scholar
  • 22. Pan American Health Organization (PAHO). Health indicators. Conceptual and operational considerations; 2015. Available from:,performance%20of%20a%20health%20system [Last accessed: June 08, 2022]. Google Scholar
  • 23. Hall W, Weier M. Assessing the public health impacts of legalizing recreational cannabis use in the USA. Clin Pharmacol Ther 2015;97(6):607–615; doi: 10.1002/wps.20735 Crossref, MedlineGoogle Scholar
  • 24. Lake S, Kerr T, Werb D, et al. Guidelines for public health and safety metrics to evaluate the potential harms and benefits of cannabis regulation in Canada. Drug Alcohol Rev 2019;38(6):606–621; doi: 10.1111/dar.12971 Crossref, MedlineGoogle Scholar
  • 25. van Ours JC, Williams J. The effects of cannabis use on physical and mental health. J Health Econ 2012;31(4):564–577; doi: 10.1016/j.jhealeco.2012.04.003 Crossref, MedlineGoogle Scholar
  • 26. GENCAT. Health survey of Catalonia. GENCAT: Barcelona, Spain. Available from: [Last accessed: June 08, 2022]. Google Scholar
  • 27. O’Reilly P. Methodological issues in social support and social network research. Soc Sci Med 1988;26:861–873; doi: 10.1016/0277-9536(88)90179-7 CrossrefGoogle Scholar
  • 28. Tennant R, Hiller L, Fishwick R, et al. The Warwick-Edinburgh mental well-being scale (WEMWBS): Development and UK validation. Health Qual Life Outcomes 2007;5:63–76; doi: 10.1186/1477-7525-5-63 Crossref, MedlineGoogle Scholar
  • 29. Castellví P, Forero CG, Codony M, et al. The Spanish version of the Warwick-Edinburgh mental well-being scale (WEMWBS) is valid for use in the general population. Qual Life Res 2014;23(3):857–868; doi: 10.1007/s11136-013-0513-7 Crossref, MedlineGoogle Scholar
  • 30. Directorate-General for Communication. Mental Well-being. Special Eurobarometer 248/Wave 64.4. European Commission: Brussels, Belgium; 2006. Google Scholar
  • 31. Watson DP, Florian Wallace C. Second European Quality of Life Survey: Subjective Well-Being in Europe. Office for Official Publications of the European Communities: Luxemburg; 2010. Google Scholar
  • 32. Kroenke K, Strine TW, Spitzer RL, et al. The PHQ-8 as a measure of current depression in the general population. J Affect Disord 2009;114(1–3):163–173; doi: 10.1016/j.jad.2008.06.026 Crossref, MedlineGoogle Scholar
  • 33. Eurostat. Quality Report of the Second Wave of the European Health Interview Survey: 2018 Edition. Publications Office of the European Union: Luxembourg; 2018. Available from: [Last accessed: June 7, 2022]. Google Scholar
  • 34. Barkus EJ, Stirling J, Hopkins RS, et al. Cannabis-induced psychosis-like experiences are associated with high schizotypy. Psychopathology 2006;39(4):175–178; doi: 10.1159/000092678 Crossref, MedlineGoogle Scholar
  • 35. Institut d’Estadística de Catalunya (IDESCAT). Level of education achieved by the population aged 15 or over. Institut d’Estadística de Catalunya (IDESCAT): Barcelona, Spain. Available from: [Last accessed: October 25, 2022]. Google Scholar
  • 36. Institut d’Estadística de Catalunya (IDESCAT). Employed population and employment rate. Institut d’Estadística de Catalunya (IDESCAT): Barcelona, Spain. Available from: [Last accessed: October 25, 2022]. Google Scholar
  • 37. EDADES. Report on the Results for Catalonia of the Home Survey on Alcohol and Drugs in Spain. Ministerios de Sanidad, Plan Nacional sobre Drogas: Madrid, Spain. Available from: [Last accessed: July 07, 2022]. Google Scholar
  • 38. Vanyukov MM, Tarter RE, Kirillova GP, et al. Common liability to addiction and “gateway hypothesis”: Theoretical, empirical and evolutionary perspective. Drug Alcohol Depend 2012;123(Suppl 1):3–17; doi: 10.1016/j.drugalcdep.2011.12.018 CrossrefGoogle Scholar
  • 39. Secades-Villa R, Garcia-Rodriguez O, Jin CJ, et al. Probability and predictors of the cannabis gateway effect: A national study. Int J Drug Policy 2015;26(2):135–142; doi: 10.1016/j.drugpo.2014.07.011 Crossref, MedlineGoogle Scholar
  • 40. Noël Wm, Wang J. Is Cannabis a Gateway Drug? Key Findings and Literature Review. National Institue of Justice: Washington, DC, USA. Available from: [Last accessed: July 07, 2022]. Google Scholar
  • 41. Tzilos GK, Reddy MK, Caviness CM, et al. Getting higher: Co-occurring drug use among marijuana-using emerging adults. J Addict Dis 2014;33:202–209; doi: 10.1080/10550887.2014.950024 Crossref, MedlineGoogle Scholar
  • 42. Smith GW, Farrell M, Bunting BP, et al. Patterns of polydrug use in Great Britain: Findings from a national household population survey. Drug Alcohol Depend 2011;113:222–228; doi: 10.1016/j.drugalcdep.2010.08.010 Crossref, MedlineGoogle Scholar
  • 43. Drug Policy Alliance (DPA). Debunking the “Gateway” Myth. DPA: New York, USA. Available from: [Last accessed: July 07, 2022]. Google Scholar
  • 44. Ona G, Kohek M, Massaguer T, et al. Ayahuasca and public health: Health status, psychosocial well-being, lifestyle, and coping strategies in a large sample of ritual ayahuasca users. J Psychoactive Drugs 2019;51(2):135–145; doi: 10.1080/02791072.2019.1567961 Crossref, MedlineGoogle Scholar
  • 45. Kohek M, Ona G, van Elk M, et al. Ayahuasca and public health II: Health status in a large sample of ayahuasca-ceremony participants in the Netherlands. J Psychoactive Drugs 2022;1–12; doi: 10.1080/02791072.2022.2077155 Crossref, MedlineGoogle Scholar
  • 46. World Health Organization (WHO). The health and social effects of nonmedical cannabis use. WHO: Geneva, Switzerland. Available from: [Last accessed: July 07, 2022]. Google Scholar
  • 47. Walsh JH, Maddison KJ, Rankin T, et al. Treating insomnia symptoms with medicinal cannabis: A randomized, crossover trial of the efficacy of a cannabinoid medicine compared with placebo. Sleep 2021;44(11):zsab149; doi: 10.1093/sleep/zsab149 Crossref, MedlineGoogle Scholar
  • 48. Campbell LM, Tang B, Watson CW, et al. Cannabis use is associated with greater total sleep time in middle-aged and older adults with and without HIV: A preliminary report utilizing digital health technologies. Cannabis 2020;3(2):180–189; doi: 10.26828/cannabis.2020.02.005 Crossref, MedlineGoogle Scholar
  • 49. Kaul M, Zee PC, Sahni AS. Effects of cannabinoids on sleep and their therapeutic potential for sleep disorders. Neurotherapeutics 2021;18(1):217–227; doi: 10.1007/s13311-021-01013-w Crossref, MedlineGoogle Scholar
  • 50. Kolla BP, Hayes L, Cox C, et al. The effects of cannabinoids on sleep. J Prim Care Community Health 2022;13:21501319221081277; doi: 10.1177/21501319221081277 CrossrefGoogle Scholar
  • 51. Bouso JC, Jiménez-Garrido D, Ona G, et al. Quality of life, mental health, personality and patterns of use in self-medicated cannabis users with chronic diseases: A 12-month longitudinal study. Phytother Res 2020;34(7):1670–1677; doi: 10.1002/ptr.6639 Crossref, MedlineGoogle Scholar
  • 52. Gruber SA, Sagar KA, Dahlgren MK, et al. The grass might be greener: Medical marijuana patients exhibit altered brain activity and improved executive function after 3 months of treatment. Front Pharmacol 2018;8:983; doi: 10.3389/fphar.2017.00983 Crossref, MedlineGoogle Scholar
  • 53. Reiman A. Cannabis as a substitute for alcohol and other drugs. Harm Reduct J 2009;6:35; doi: 10.1186/1477-7517-6-35 Crossref, MedlineGoogle Scholar
  • 54. Boehnke KF, Litinas E, Clauw DJ. Medical cannabis use is associated with decreased opiate medication use in a retrospective cross-sectional survey of patients with chronic pain. J Pain 2016;17:739–744; doi: 10.1016/j.jpain.2016.03.002 Crossref, MedlineGoogle Scholar
  • 55. D’Souza DC, Cortes-Briones JA, Ranganathan M, et al. Rapid changes in CB1 receptor availability in cannabis dependent males after abstinence from cannabis. Biol Psychiatry Cogn Neurosci Neuroimaging 2016;1(1):60–67; doi: 10.1016/j.bpsc.2015.09.008 CrossrefGoogle Scholar
  • 56. Schlag AK, Hindocha C, Zafar R, et al. Cannabis based medicines and cannabis dependence: A critical review of issues and evidence. J Psychopharmacol 2021;35(7):773–785; doi: 10.1177/0269881120986393 Crossref, MedlineGoogle Scholar
  • 57. Teresi L, Haroutunian H. Hijacking the Brain: How Drug and Alcohol Addiction Hijacks Brains. Authorhouse: Bloomington, Indiana, USA; 2011. Google Scholar
  • 58. Carballo JL, Fernández-Hermida JR, Secades-Villa R, et al. Natural Recovery from Alcohol and Drug Problems: A Methodological Review of the Literature from 1999 Through 2005. In: Promoting Self-Change from Addictive Behaviors. (Klingemann HSobell LC. eds.) Springer US: New York, NY, USA; 2007, pp. 87–101. Google Scholar
  • 59. Lopez-Quintero C, Hasin DS, de los Cobos JP, et al. Probability and predictors of remission from life-time nicotine, alcohol, cannabis or cocaine dependence: Results from the national epidemiologic survey on alcohol and related conditions. Addiction 2011;106(3):657–669; doi: 10.1111/j.1360-0443.2010.03194.x Crossref, MedlineGoogle Scholar
  • 60. Heyman GM. Quitting drugs: Quantitative and qualitative features. Ann Rev Clin Psychol 2013;9:29–59; doi: 10.1146/annurev-clinpsy-032511-143041 Crossref, MedlineGoogle Scholar
  • 61. Bouso JC, González D, Fondevila S, et al. Personality, psychopathology, life attitudes and neuropsychological performance among ritual users of Ayahuasca: A longitudinal study. PLoS One 2012;7(8):e42421; doi: 10.1371/journal.pone.0042421 Crossref, MedlineGoogle Scholar
  • 62. NHS. Symptoms: Clinical Depression. National Health System (NHS): London. UK. Available from: [Last accessed: October 26, 2022]. Google Scholar
  • 63. Jiménez-Vinaja R, Imbernón M, Parés-Bayerri A, et al. Jailhouse rock: Health status, patterns of use, and subjective benefits of cannabis use in a sample of inmates in Spanish prisons. Rev Esp Sanid Penit 2022;24(1):9–15; doi: 10.18176/resp.00044 Crossref, MedlineGoogle Scholar

Cite this article as: Jiménez JH, Oña G, Alcázar-Córcoles MÁ, Bouso JC (2023) Cannabis and public health: a study assessing regular cannabis users through health indicators, Cannabis and Cannabinoid Research X:X, 1–9, DOI: 10.1089/can.2022.0231.Abbreviations Used

CEQCannabis Experiences Questionnaire
CSCscannabis social clubs
ESCAEnquesta de Salut de Catalunya
PHQ-8eight-item Patient Health Questionnaire depression scale
WEMWBSWarwick–Edinburgh Mental Well-being Scale