Context: In the 1990s, cannabis consumption in France increased considerably. So, in 10 years, the number of adolescents reporting regular cannabis use (10 or more times during the last 12 months) tripled. In 2004, an official program to address problems related to cannabis addiction was implemented. As part of this program, specific outpatient settings for cannabis use disorders were created.

Objective: We present the sociodemographic characteristics, the prevalence of cannabis, alcohol and others psychoactive substances and the prevalence of mental disorders in 90 cannabis users seen at an outpatient specific setting for cannabis use disorders in the Lariboisière hospital (a university hospital in Paris).

Measures: Twelve months prevalence of substance abuse and dependence, psychiatric diagnoses based on the DSM-IV and the Mini-International Neuropsychiatric Interview (MINI) results are described.

Results: The study population had the following characteristics: 67% male, mean age 27.5 (S.D.=8.4) years and 59% single or divorced. Approximately, two-thirds of the users (67%) were students or currently working and 32% were unemployed. Twenty-two percent of the cannabis users received unemployment, welfare or disability benefits and 11% declared no source of revenue. Most of the users (63%) decided on their own to seek care at the setting. Seventy-three percent of the subjects had seen a psychologist or a psychiatrist in the past, with or without relation to cannabis use. By far, most of the users were cannabis dependent (82%) and 9% cannabis abusers in the last 12 months according to DSM-IV criteria prior to their visit. Seven percent of the cannabis users had alcohol dependence and 7% were abusers. The 12 months prevalence of cocaine or ecstasy dependence was 2% and the prevalence of benzodiazepines, heroin or stimulants dependence 1%. The main substances used over lifetime were tobacco (99%); alcohol (96%); cocaine (41%); benzodiazepines and hypnotics (41%); ecstasy (40%) and heroin (23%). Four percent of cannabis users had a history of intravenous drug use. The main consumption mode of cannabis in France is the blunt. About three-quarters of the consumption is in the form of resin (hashish) and one-quarter as marijuana (grass). The average consumption of cannabis in the last six months was equivalent to 5.8 blunts per day (S.D.=4.4) and 12 g per week (S.D.=10.5), and the average monthly cost was 159 euro (S.D.=133) (234 USD, S.D.=196). The prevalence of psychiatric disorders according to DSM-IV criteria in the sample is high. A current mood disorder was present in 48% and an anxiety disorder in 55% of the cannabis users in the last 12 months. The prevalence of affective disorders in the last 12 months was major depressive disorder (38%), dysthymia (19%), hypomania (3%) and mania (1%). The prevalence of anxiety disorders in the last 12 months was social phobia (29%); generalised anxiety disorder (17%); panic disorder with or without agoraphobia (16%); obsessive compulsive disorder (12%); agoraphobia without panic disorder (9%) and post-traumatic stress disorder (5%). The prevalence of schizophrenia was 4%. The prevalence of bulimia was 4% and no anorexia. Women are more likely to report an affective disorder (64% versus 41%; p=0.04) or a post-traumatic stress disorder (17% versus 0%; p<0.001) in the last 12 months. The prevalence of family history for psychiatric disorders was 52% and for addiction, 59%.

Conclusions: The cannabis users seen in our specific setting are a fairly homogeneous group and for the most part addicted to cannabis only, but with very high rates of dependence. Indeed, other than tobacco dependence, 80% of the users were only dependent on, or abused on cannabis in the last 12 months. In comparison with the cohort of French cannabis users (n=4202) seen at specific outpatient settings for marijuana users in 2005, cannabis users seen in Lariboisière Hospital are older, the percentage of females is greater, they are more dependent on marijuana and have a high prevalence of affective and anxiety disorders.