Teenagers who smoke a single cannabis joint can suffer life-long consequences, according to a new study. Taking the drug once or twice by the age of 14 may lead to greater ‘grey matter’ volume in key brain areas linked to emotion and memory, the research found. More brain volume potentially led to worse IQ, the data showed.

http://www.jneurosci.org/content/early/2019/01/14/JNEUROSCI.3375-17.2018

https://metro.co.uk/2019/01/15/smoking-single-cannabis-joint-can-lower-teenagers-iq-forever-8345890/

https://psiquiatria.com/adicciones/fumar-un-solo-porro-puede-cambiar-el-cerebro-del-adolescente/