For many years cannabis has been widely regarded as a ‘safe’ recreational drug. However, there is growing evidence that in young people in particular it may have significant adverse effects on mental health.
The potential effect of cannabis on mental health is an increasingly important problem because cannabis is now very widely used by young people, to the extent that recent surveys in Australia indicate that probably 70 to 80% of young Australians have used cannabis. The patterns of use have changed such that a greater proportion of young people use cannabis regularly, and the cannabis used is more potent.
Furthermore, because tetrahydrocannabinol is highly lipid soluble it accumulates in fat tissue and continues to be released long after intake has ceased. It accumulates in central nervous system tissue in particular, and the recently identified endogenous cannabinoid ligands and receptors can influence other neurotransmitter systems. It is not surprising, therefore, that there is a significant link between substantial cannabis use and major psychiatric illness.