"The total number of patients registered in 2009 through the BTDIR [Belgian Treatment Demand Indicator Register] was 9300. Table 5.2 shows the number of patients in treatment by main substance and by gender. The unknown gender records were not indicated. A large majority of patients (78.3%) was registered in outpatient centres, 13.1% in inpatient centres and 8.6% in low-threshold agencies. The main substances were opiates (in 37.3% of the treatment demands) and cannabis (27.5%). The other substances were cocaine (14.1%), stimulants such as amphetamines (10.2%), hypnotics and sedatives (3.7%) and unknown or other substances (7.2%). Figure 5.1 represent the age category of patients in treatment by primary drug. Patients in treatment for hypnotics are the oldest: 41.4% of them are aged 40 years or older. On the opposite end of the spectrum, patients in treatment for cannabis are the youngest, with 76.0% of them being under the age of 30. The percentage of new patients under the age of 30 who are being treated for a stimulant-, cocaine- or opiate-related disorder, is 58.6%, 48.8%, and 40.6%, respectively.
"The gender distribution of patients by primary drug is presented in Figure 5.2. Patients entering treatment for the misuse of hypnotics are the group with the greatest percentage of women (36.3%), followed by patient in treatment for stimulants (29.9%). The percentages of women among patients in treatment for opiates, cocaine or cannabis are 18.4%, 20.7%, and 15.4%, respectively."

Source

Deprez, Nathalie, et al., "2011 National Report (2010 data) to the EMCDDA by the Reitox National Focal Point" (Brussels, Belgium: OD Public Health and Surveillance, Scientific Institute of Public Health, October 2011), WIV-ISP/EPI REPORTS N° 002, p. 107.
http://www.emcdda.europa.eu/a…