Australasian Science: Australia's authority on science since 1938

Smoking Dope Just Once as a Teen Could Change Your Brain


Teenagers who say they have only smoked cannabis once or twice have both structural and cognitive changes to their brains.

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“The results of this study (Journal of Neuroscience, suggest that even in small doses, cannabis use can result in structural brain changes, most notably increased grey matter volume.

Given that adolescence is a time of rapid brain maturation/reorganisation, any changes which are induced by external forces, such as cannabis or alcohol use, rather than normal developmental factors must be viewed with some concern.

The study also noted a large degree of overlap between low-dose users and non-users, suggesting that some individuals may be more at risk than others, although it is not yet possible to identify those at risk.

As a consequence, the overall results suggest that cannabis, like alcohol and other recreational drugs, should be avoided until brain development/maturation is complete; that is, until at least the age of 21.

Paradoxically, the finding that low-dose cannabis use can increase grey matter volume may have therapeutic implications. Previous studies have suggested that some individuals suffering from some disorders (e.g. major depressive disorder) have reduced grey matter volume. Thus low-dose cannabis use, under medical supervision, may have the potential to reverse this reduction, although a significant amount of research needs to be conducted...

The full text of this article can be purchased from Informit.