Science Cannabis

230 THE SCIENCE OF MARIJUANApsychological dependence. A number of studies have shown that applicationof the internationally agreed DSM-IV (1994) criteria for substancedependence reveals that a substantial number of regular cannabis userscan be classified as dependent, even though most would not admit tothat description. Wayne Hall and Nadia Solowij, internationally recognizedexperts in the field of addiction research, describe how they viewthis situation:Dependence on cannabis is the most prevalent and under-appreciated riskof regular cannabis users. About 10% of those who ever use cannabis, andone third to one half of those who use it daily will lose control over theircannabis use and continue to use the drug in the face of problems theybelieve are caused or exacerbated by its use. . . . Uncertainty remains asto how difficult it is to overcome cannabis dependence and what is the bestway to assist individuals to become abstinent.Hall and Solowij (1997)Dr. Hall in testimony to the House of Lords Report (1998) said:By popular repute, cannabis is not a drug of dependence because it doesnot have a clearly defined withdrawal syndrome. There is, however, littledoubt that some users who want to stop or cut down their cannabis usefind it very difficult to do so, and continue to use cannabis despite theadverse effects that it has on their lives. . . . Epidemiological studies suggestthat cannabis dependence, in the sense of impaired control over use,is the most common form of drug dependence after tobacco and alcohol,affecting as many as one in ten of those who ever use the drug.Is this an exaggeration of the true situation, reflecting the particularproblems that the authors see in their home country, Australia, which hasa particularly high rate of cannabis consumption? One way of measuringthe extent of cannabis dependence is by the number of people who seektreatment for it. In Britain, the 1996 Department of Health figures showthat in 6% of all contacts with regional drug clinics, cannabis was themain drug of abuse. A similar figure, that cannabis users constitute 7% ofall new admissions to drug treatment centers in Australia was also reportedrecently (House of Lords, 1998). In the United States NIDA reportsthat 100,000 people are enrolled for the treatment of cannabis de-