Adolescent pothead mice susceptible to psychosis

In a study published today in the journal Neuropsychopharmacology, Dublin-based medical scientist Colm O’Tuathaigh and others show that adolescent male mice are particularly susceptible to cannabis-induced psychosis. This follows from previous research which indicates an association between cannabis use and psychotic illness in young humans, but which has yet to identify the specific causal mechanism involved.

That cannabis can have adverse effects in still developing animals is not surprising. But it is useful to have the effect quantified, even if O’Tuathaigh and his colleagues caution that further studies are needed to confirm whether the results apply also to human beings.

Cannabis, along with a number of other stimulants, depressants and hallucinogens, alcohol among them, has a shocking effect on the central nervous system, and its impact is strongly physical as well as mental. Given what we know about such psychoactive drugs, they should only be used in moderation, if at all, and it is common sense to dissuade adolescent young people from indulging. After all, they are by definition still growing, and can do without the deleterious effect of chemical agents that can seriously upset their bodies’ fine biochemical and hormonal balances.

But what of more socially acceptable drugs that have a similarly strong physical effect, and are used habitually, often by young people? Take coffee, for example. Stimulants such as caffeine can, like cannabis, induce psychosis. Over the years there has been a fair amount of research into the effects on the central nervous system of caffeine, yet rarely does one see stories in the mass media about the dangers of coffee to teenagers. Not so when it comes to cannabis. I have no doubt that O’Tuathaigh’s work will be widely reported in the coming days.

Further reading: O’Tuathaigh et al., “Chronic adolescent exposure to delta-9-tetrahydrocannabinol in COMT mutant mice: impact on psychosis-related and other phenotypes”, Neuropsychopharmacology (2010).