Illicit Drug use Starts with Cannabis

Cannabis use leads to the use of other illicit drugs according to a recent study by the University of Otago and published in the Addiction journal.

The study of 1000 Christchurch young people between the ages of 15 and 25 disclosed that nearly 4 out 5 of the sample had used cannabis by age 25 with 40 per cent of those going on to use other illicit drugs.

The great majority of users had used cannabis before other illicit drugs with the tendency most evident for regular cannabis users.

Adolescent cannabis users were more likely to move onto other illicit drugs than young adults.

Suggested reasons for the progression onto other illicit drugs were-

  • Cannabis use may lead to changes in brain chemistry that make young people more susceptible to other illicit drugs.
  • Experiences with cannabis may encourage experimentation with other illicit drugs.
  • Cannabis users obtain their illicit drugs from drug dealers which exposes them to other illicit drugs

(Source: University of Otago NZ, media release, 14 March 2006)


This study highlights other studies that indicate that cannabis is a gateway to other illicit drug use.

The study is concerning as adolescents and teenagers are more likely to progress onto other illicit drug use, therefore commencing the harm to themselves at an earlier age.

As Cannabis is the most widely used illicit drug in Australia and use is commencing earlier, then mental illness associated with cannabis use is likely to commence at an earlier age.

Cannabis and other illicit drug use by teenagers can be eliminated by detoxification and rehabilitation programs for cannabis users.