Long-term cannabis use does not negatively impact health, Spanish study finds

Results produced by a study that analysed data from 600,000 Spanish residents who regularly consumed cannabis indicate that long-term cannabis use does not contribute to the deterioration of health.

Using indicators that were specifically designed to give an accurate picture of health, researchers analysed survey responses from the people who replied that they had used cannabis recently and compared them to responses from the general population.

Cannabis consumption in Spain

Cannabis consumption amongst the people of Spain is among the highest in Europe, behind only Portugal and Luxembourg. It has a strong scene, there are approximately 700 cannabis social clubs across the country that operate in a legally grey area due to the supply and distribution of cannabis being illegal. 

Cannabis social clubs in Spain have to follow strict guidelines which are enforced, sometimes rigorously by the various Spanish law enforcement agencies. These include rules such as all people entering and using a club have to be members, and cannabis has to be supplied at cost to members and grown in a cooperative way. 

Many of the clubs operate in Catalonia, one of the 17 autonomous regions of Spain. These autonomous regions, or autonomies as they are collectively known, often set their own drug policy and it is thought that this is one of the reasons why the Spanish Government handles drug possession with such a soft touch.

Decriminalisation of cannabis and other drugs is happening across Europe, however, possession of drugs in Spain at a national level has never been decriminalised. There have never actually been criminal penalties imposed for the possession or use of drugs, even during the years of dictatorship under General Franco. 

However, administrative sanctions, which can include fines, are often handed out for people caught with drugs in public, as only consumption in private is allowed. 

Study details 

Published in the Journal Cannabis and Cannabinoid Research, and carried out in Barcelona, Spain, researchers used a sample of 419 subjects from the 600,000 respondents of a 2019 – 2020 national population survey who lived in Catalonia and had used cannabis in the previous 30 days.  

Using specific methods to analyse data from respondents, researchers calculated that the sample of 419 regular cannabis consumers represented the total who said they consumed cannabis to an accuracy of over 95%.

The individuals included in the cannabis consuming sample had an average age of 33 years, mainly worked in service, administration or trade jobs, and nearly three quarters had completed some form of higher-education (after leaving senior school at 16).

When asked about past drug use 60% of the sample said they had used MDMA, 57% had used cocaine, 51% LSD, mushrooms or other psychedelics, 40% amphetamine and 23% had used ketamine before. 

Commenting on previous drug use of the sample, the study authors said “The study sample reported higher drug use than the general population … However, this higher use does not seem to be associated with harmful effects on health, as reflected in the indicators used.”

Comparison with the general population

Most of the indicators used by researchers to assess the health of respondents did not show a deterioration when compared to the general population. Indicators included; BMI, cholesterol, positive perception of health, and fruit and vegetable intake.

88% of the sample had a positive perception of their health compared to the general population, 67% of cannabis users had a normal BMI compared to the general population, and ten minutes or more a day of walking was completed by 76% of the cannabis sample compared to 70% of the population.

To gauge mental health, researchers asked various questions, including ‘How do you feel during cannabis use?’ 94% of respondents indicated that they experienced ‘happiness’, 92% felt ‘full of ideas’, and 81% felt that they ‘had a better understanding of the world’.

Researchers reported in their study that, “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.”

The results of this study paint an interesting picture of the general physical and mental health of cannabis consumers in Spain, and provide a useful perspective when compared to the general population. The study authors recommend the inclusion of more cannabis related questions in future national population surveys, and warned against the risk of cannabis users developing dependency problems. 

“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” researchers said

“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.”

“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 behaviours 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.”