In this section, we describe:
- Prevalence of cannabis use
- Patterns of cannabis use
- Possible harms of cannabis use
- Treatment and demand-reduction for cannabis use
Last updated : 19-09-2025
Prevalence of cannabis use
Cannabis use in the general population
In Belgium
Health Interview Survey, 2018, Belgium, Sciensano
The prevalence of the last year use of cannabis was 7.0% in 2018.
In Flanders
Preventiebarometer, 2022, Flanders, Sciensano
In Flanders in 2022, 6.3% of the population aged 18 to 64 used cannabis in the 12 months prior to the survey. This result is comparable with the result from the Health Interview Survey in 2018 in Flanders (6.2%).
Prevalence of last year cannabis use in the general population aged 18-64 years old
Figure 1a | Preventiebarometer, 2022, Flanders, Sciensano
Among the young men aged 18-24 years the last year prevalence was 20.3% and among young women, 16.1%. This prevalence is respectively of 20.3% and 16.1% for the 25-34 year-olds, of 11.4% and 6.7% for the 35-44 year-olds, 3.4% and 1.0% for the 45-54 year-olds and of 1.7% and 0.0% for the 55-64 year-olds.
Prevalence of last year cannabis use in the general population aged 18-64 years old, by age category and gender
Figure 1b | Preventiebarometer, 2022, Flanders, Sciensano
Cannabis use among school-aged children
In Flanders
Leerlingenbevraging, 2022-2023, Flanders, VAD
Prevalence and trends
Cannabis remains the most commonly used drug among school-aged children in Flanders. Lifetime use (proportion of people who have ever used) is reported by 8.6% of students aged 12-18. However, cannabis use has decreased significantly since 2012-2013, with a lifetime use of 17.3%. This decline is consistent across all age groups and for both boys and girls.
Prevalence of lifetime use of cannabis among school-aged children
Figure 2a | Leerlingenbevraging, 2022-2023, Flanders, VAD
Prevalence by age
Cannabis use prevalence increases with age, with lifetime prevalence at 1.5% among 12-14-year-olds, 10.7% among 15-16-year-olds, and 23.0% among 17-18-year-olds.
Prevalence of lifetime use of cannabis among school-aged children, by age
Figure 2b | Leerlingenbevraging, 2022-2023, Flanders, VAD
Prevalence by gender
Gender differences show that boys report higher lifetime use (10.0%) compared to girls (7.8%).
Prevalence of lifetime use of cannabis among school-aged children, by gender
Figure 2c | Leerlingenbevraging, 2022-2023, Flanders, VADAvailability and acceptance
25.1% of the respondents indicated in 2022-2023 having at least one friend who uses cannabis. Among 15-16 year-olds, this is 33.5% and among 17-18 year-olds it is 47.6%. Compared with ten years ago (2012-2013), this is a lower prevalence (56.3% among 15-16 year-olds and 67.1% among 17-18 year-olds).
School-aged children with at least one friend reporting the use of cannabis, by age
Figure 2d | Leerlingenbevraging, 2022-2023, Flanders, VAD19.7% of the students still find it easy to obtain cannabis, which is also a decline compared with then years ago (29.3%). In relation to the social acceptance of cannabis use, 4.0% of the respondents report that their friends would approve the use of cannabis. Compared with 10 years ago, this trend remains stable (4.4% in 2012-2013).
Availability and acceptance of cannabis use among school-aged children
Figure 2e | Leerlingenbevraging, 2022-2023, Flanders, VAD
Lifetime use prevalence
Between 2018 and 2022, cannabis use among Flemish school-aged children remained stable. Lifetime use was reported by 14.0% of the respondents.
Prevalence of lifetime use of cannabis among school-aged children in Flanders
Figure 3a | HBSC, 2022, Flanders, UGentPrevalence by age
Cannabis use increases with age. Lifetime prevalence in 2022 is 3.2% among 13-14-year-olds and rises to 27.3% for 17-18-year-olds.
Prevalence of lifetime use of cannabis among school-aged children, by age (Flanders)
Figure 3b | HBSC, 2022, Flanders, UGentPrevalence by gender
Boys reported higher lifetime use (15.8%) compared to girls (12.3%).
Prevalence of lifetime use of cannabis among school-aged children, by gender (Flanders)
Figure 3c | HBSC, 2022, Flanders, UGentPrevalence by type of education
Students in vocational education reported the highest cannabis use, with 24.5% reporting lifetime use. By contrast, students in general education reported lower lifetime prevalence (14.9%).
In Wallonia
HBSC, 2022, Brussels-Wallonia, Sipes
Lifetime use prevalence
Between 2018 and 2022, cannabis use among school-aged children in Wallonia remained stable. Lifetime use was reported by 23.5% of the respondents in 2018, and by 23.0% of the respondents in 2022.
Prevalence of lifetime use of cannabis among school-aged children in Wallonia
Figure 4a | HBSC, 2022, Brussels-Wallonia, SipesPrevalence by age
The lifetime prevalence in Wallonia for cannabis use is 9.5% for 13-14 year-olds, 16.7% for the 15-16 year-olds and 34.7% for the 17-18 year-olds.
Prevalence of lifetime use of cannabis among secondary school students, by age (Wallonia)
Figure 4b | HBSC, 2022, Brussels-Wallonia, SipesPrevalence by gender
The lifetime prevalence in Wallonia for cannabis use is 24.3% for boys and 21.7% for girls.
Prevalence of lifetime use of cannabis among secondary school students, by gender (Wallonia)
Figure 4c | HBSC, 2022, Brussels-Wallonia, Sipes
In Brussels
HBSC, 2022, Brussels-Wallonia, Sipes
Lifetime use prevalence
Between 2018 and 2022, cannabis use among school-aged children in Brussels dropped slightly. Lifetime use was reported by 22.1% of the respondents in 2018, and by 17.0% of the respondents in 2022.
Prevalence of lifetime use of cannabis among school-aged children in Brussels
Figure 5a | HBSC, 2022, Brussels-Wallonia, SipesPrevalence by age
The lifetime prevalence in Brussels for cannabis use is 12.8% for 13-14 year-olds, 15.4% for the 15-16 year-olds and 21.6% for the 17-18 year-olds.
Prevalence of lifetime use of cannabis among secondary school students, by age (Brussels)
Figure 5b | HBSC, 2022, Brussels-Wallonia, SipesPrevalence by gender
The lifetime prevalence in Brussels for cannabis use is 15.6% for boys and 18.1% for girls.
Prevalence of lifetime use of cannabis among secondary school students, by gender (Brussels)
Figure 5c | HBSC, 2022, Brussels-Wallonia, SipesCannabis use among post-secondary school students
In Flanders
In hogere sferen, 2021, Flanders, VAD
Prevalence and trends
Cannabis remains the most commonly used illicit drug among students, with 27.0% using it in the past 12 months, which is slightly higher than in 2017 (23.8%).
Trends in last year cannabis use among students
Figure 6a | In hogere sferen, 2021, Flanders, VAD
Prevalence by gender
Prevalence of use is significantly higher among male students, with 35.7% reporting last-year use compared to 20.1% of female students.
Prevalence of last year cannabis use among students, by gender
Figure 6b | In hogere sferen, 2021, Flanders, VAD
Cannabis use in nightlife settings
In Flanders
Het uitgaansonderzoek, 2022, Flanders, VAD
Prevalence and trends
Cannabis remains the most widely used illicit drug in nightlife settings, although use has declined over the past 20 years (from 47.8% to 35.2% in 2022). Nevertheless, last year use among the past 10 years remained stable as shown in figure 7.
65.4% of people in nightlife settings have ever used cannabis in 2022, which is an increase compared with 56.9% in 2015.
Evolution of last year cannabis use among people in nightlife settings
Figure 7 | Het uitgaansonderzoek, 2022, Flanders, VAD
In Brussels and Wallonia
Drogues Risquer Moins, 2023, Brussels-Wallonia, Modus Vivendi (published by Eurotox)
Prevalence and cannabis use patterns
Cannabis is the most commonly mentioned drug in nightlife settings, with 53.6% of the respondents indicating lifetime cannabis use in recreational settings. 31.2% respondents indicated to use sometimes cannabis during nightlife and 40.8% of the respondents reported the use of cannabis at the event where the survey was conducted.
Patterns of cannabis use
Age of first use
Among people who currently use cannabis
Drug Vibes, 2023, Belgium, Sciensano
Two in five people (38.9%) who reported using cannabis in the month before the survey used cannabis for the first time before the age of 16, and one-third (34.5%) first used it between the ages of 16 and 17.
Age of the first use of cannabis of people who reported using cannabis in the month before the survey
Figure 8 | Drug Vibes, 2023, Belgium, Sciensano
Among people in treatment
The mean age of first use of cannabis is 16 years old among people who had a treatment episode with cannabis as primary substance in 2023.
Frequency of use
Among people who currently use cannabis
Drug Vibes, 2023, Belgium, Sciensano
About two in five people who reported using cannabis in the month before the survey used it on a daily basis (37.5%) in 2023. 41.7% of the respondents reported weekly use and 20.8% of the people who used cannabis used it on a monthly basis.
Frequency of use of cannabis by people who reported using cannabis in the month before the survey
Figure 9 | Drug Vibes Survey, 2023, Belgium, Sciensano
Among people in treatment
60,0% of all people in treatment for cannabis used this substance on a daily basis during the last 30 days before entering treatment.
Quantity of cannabis used
Among people who currently use cannabis
Drug Vibes Survey, 2023, Belgium, Sciensano
Around two-thirds of the people (66.5%) who reported using cannabis in the month before the survey mentioned that on a typical day of use, they consume 2 or fewer portions of cannabis products (e.g., joints). Around the same proportion (64.1%) use 0.2g or less of cannabis per portion.
Number of portions of cannabis products used on typical day of use by people who reported using cannabis in the month before the survey
Figure 10 | Drug Vibes Survey, 2023, Belgium, Sciensano
Popular purchase channels for cannabis
Among people who currently use cannabis
Drug Vibes Survey, 2023, Belgium, Sciensano
The most common way to obtain cannabis by people who reported using cannabis in the month before the survey, is from a drug dealer (43.5%), followed by buying from a friend (22.1%), receiving it for free (21.4%), or purchasing it in a coffee shop (18.6%). A small proportion of people grow their own cannabis (7.1%) or buy it online (4.7%).
Main channels for cannabis purchase by people who reported using cannabis in the month before the survey
Figure 11 | Drug Vibes Survey, 2023, Belgium, Sciensano
Popular consumption locations for cannabis use
Among people who currently use cannabis
Drug Vibes Survey, 2023, Belgium, Sciensano
The majority (88.5%) of people who reported using cannabis in the month before the survey report using it at home, either alone or with others. Only 8.0% use it in the street, 2.4% use it in commercial venues such as bars or clubs.
Main locations where cannabis is consumed by people who reported using cannabis in the month before the survey
Figure 12 | Drug Vibes Survey, 2023, Belgium, Sciensano
Main motivations for using cannabis
Among people who currently use cannabis
Drug Vibes Survey, 2023, Belgium, Sciensano
The main reasons for using cannabis by people who reported using cannabis in the month before the survey are to relax (94.8%), to get high (90.1%), to improve sleep (83.8%), and to feel euphoric (81.1%).
Main motivations for using cannabis by people who reported using cannabis in the month before the survey
Figure 13 | Drug Vibes Survey, 2023, Belgium, Sciensano
Therapeutic use of cannabis
Among people who currently use cannabis
Drug Vibes Survey, 2023, Belgium, Sciensano
A third (34.0%) of respondents who reported using cannabis in the month before the survey mentioned using it for therapeutic reasons, primarily for stress (63.4%), sleeping disturbances (58.5%) depression (46.0%), and anxiety (41.8%). About two-thirds (65.8%) reported a large or very large improvement in their condition due to cannabis use.
Main symptoms treated with cannabis by people who reported using cannabis in the month before the survey
Figure 14 | Drug Vibes Survey, 2023, Belgium, Sciensano
Use of other substances
Among people who currently use cannabis
Drug Vibes Survey, 2023, Belgium, Sciensano
Almost half of the people (47.2%) who reported using cannabis in the month before the survey used only cannabis in the last month. 22.4% used one other illicit substance, and 30.4% used cannabis as well as at least two other illicit substances. The most common combinations were cannabis with MDMA/ecstasy (6,9%), cannabis with cocaine (5,7%), and cannabis with both MDMA/ecstasy and cocaine (3,7%).
Number of other illicit substances also used by people who reported using cannabis in the month before the survey
Figure 15 | Drug Vibes Survey, 2023, Belgium, Sciensano
Among people in treatment
Most people (59,4%) in treatment for cannabis as their primary drug are in treatment only for cannabis. Others report also problems with alcohol (17.3%), cocaine (14.1%) stimulants (9.2%) or others. On average, they report problems with 1.7 different substances, including cannabis.
Drugs which are also mentioned as another drug causing a problem among people in treatment for cannabis as the primary drug
Figure 16 | TDI, 2023, Belgium, Sciensano
Types of cannabis used
Among people who currently use cannabis
Drug Vibes Survey, 2023, Belgium, Sciensano
The results from the 2023 wave of the web survey indicated that the most popular cannabis products used by people who reported using cannabis in the month before the survey were marijuana (herbal cannabis) (97.3%), followed by hashish (cannabis resin) (43.7%), CBD (6.3%), oils (5.0%), e-liquids (3.3%) and cosmetic products (1.8%).
Type of cannabis used by people who reported using cannabis in the month before the survey
Figure 17 | Drug Vibes Survey, 2023, Belgium, SciensanoAmong people in treatment
Among people entering treatment for cannabis as a primary drug, around half of them (53,8%) did not specify the type of cannabis used, 43.6% mentioned marijuana and 2,6% hashish.
Types of cannabis reported by people entering treatment for cannabis as a primary drug
Figure 18 | TDI, 2023, Belgium, SciensanoPossible harms of cannabis use
Perceptions and attitudes towards cannabis
In Flanders
Preventiebarometer, 2022, Flanders, Sciensano
Awareness of risks
Most respondents (77.8%) recognise that cannabis can be addictive, and nearly seven out of ten (69.9%) are aware of its negative effects on memory and concentration.
Awareness of negative impacts of using cannabis
Figure 20b | Preventiebarometer, 2022, Flanders, Sciensano
Quitting cannabis
Among people who use cannabis monthly, one in four (25.3%) have tried to quit, and a similar proportion (23.9%) plan to stop using cannabis within the next year.
Intentions with respect to quitting using cannabis
Figure 20c | Preventiebarometer, 2022, Flanders, Sciensano
Negative consequences of using cannabis
Among students in post-secondary schools
In hogere sferen, 2021, Flanders, VAD
Most students who used cannabis in the previous year experienced either few or no negative consequences. Specifically, 62.8% experienced no negative effects, 14.6% experienced only one, 9.2% experienced two, and 13.4% indicated more than two negative consequences from the list provided.
The most frequent negative consequence reported is using more than intended or using the drug for longer than intended (29.5%). 19.3% felt the need to reduce their cannabis use or wanted to stop using it for more than a week, but failed to do so. The other negative consequences included in the questionnaire were indicated by about 1 out of 10 people who used cannabis in the past year. Specific attention should be given to the 10.5% who indicated that they could not meet their work or study obligations as a result of their cannabis use.
Number of negative consequences reported by students who used cannabis last year
Figure 21 | In hogere sferen, 2021, Flanders, VAD
Proportion of calls at a poison control center related to cannabis
Poison control center, 2023, Belgium (unpublished)
Among the 361 persons who had an incident related to a specific illicit substance in 2023, cannabis (including both plant based and synthetic cannabinoids) was reported in 24.7%. Among them, the proportion of incidents related to plant-based cannabis was 94.4%.
Proportion of drug-related emergency cases related to cannabis
Euro-DEN, 2022, Flanders, EMCDDA
The proportion of emergency cases with acute drug-toxicity presentations in Flanders related to cannabis, reported by two participating hospitals in Antwerp and in Ghent, is stable between 2017 and 2022 around 25.0%. It’s the second most reported drug in an emergency setting after cocaine.
Proportion of road-side tests with cannabis detection
Road-side testing, 2023, Belgium, NICC (unpublished)
In 58.5% of all people that were tested positively for driving under the influence of illicit drugs (n=8,442), the use of cannabis has been confirmed. In three-quarters (76.5%) of these cannabis tests, cannabis was the only drug detected, in 19.0% of the cases cannabis was detected together with cocaine and 5.5% with other substances such as amphetamines and opioids.
Treatment and demand-reduction for cannabis use
People in treatment
Profiles of people in treatment for cannabis use
Overview of treatment for cannabis use
In 2023, nearly one in three people (29.4%) entering treatment for alcohol or illicit substance use reported cannabis as a reason to seek help. In 13.9% of all treatment episodes, cannabis is reported as the primary substance. For 22.3% of the first-time entrants, cannabis was the primary substance.
First-time treatment
Around half (46,6%) of people entering treatment for cannabis were seeking help for the first time in their lives. This rate is significantly higher compared to first-time treatment entrants for cocaine (27,8%), other stimulants (22,2%), or opioids (11,5%).
Regional differences
The proportion of people seeking treatment for cannabis as their primary drug varied across Belgium. It was most common in Flanders (16.6%), followed by Brussels (10.8%) and Wallonia (8.3%).
Proportion of treatment demands with cannabis as primary drug — by region
Figure 22 | TDI, 2023, Belgium, Sciensano
Gender and age
Women made up 23.0% of those entering treatment for cannabis as a primary drug, which is comparable to cocaine as a primary drug (22.4%) but lower than other stimulants as a primary drug (29.6%). However, it is higher than the proportion of women entering treatment for opioids as a primary drug (19.9%). The average age of individuals in treatment for cannabis as a primary drug was 30 years old.
Referrals by the justice system
A significant number of people seeking treatment for cannabis as a primary drug were referred by the justice system (27,3%). This proportion is higher compared to referrals for cocaine as a primary drug (11,2%), opioids (7,2%), and other stimulants (22,4%).