Mice who "underwent cognitive training [and] received rewards while exploring a training arena" reduced "one measure of drug-seeking behavior" in comparison with those who "remained in their home cages." The researchers conclude, right in the abstract, that "deprivation may confer vulnerability to drug-seeking behavior and that brief interventions may promote long-term resilience."
[1] https://www.sciencedirect.com/science/article/abs/pii/S00283...
I have yet to meet an alcoholic or drug addict that has an otherwise perfectly normal life. I don't mean "highly functioning alcoholic", I'm talking about your stereotype addict. So far all of them have had one thing in common: their life was not headed in a direction they desired, and they couldn't see (an easy enough) way to get moving in that direction. After that, any substance or excuse or anxiety was "just" a coping mechanism.
Not sure if this makes sense, just needed to say this I guess.
He is trained as a medical doctor, but has learnt a lot about the psychology of addiction from his own experiences and those of patients. He worked in a drug treatment center in Vancouver and one of the things he often says is that of all the hard drug users he has seen, those who are female were all sexually abused as children.
His viewpoint is that addiction itself is not a problem - contrary to what the media would like you to believe - it's merely the minds way of dealing with whatever other traumas have been going on in your life. (When he talks about addiction he is not just talking about drugs, but all forms, including why you check HN every 20 minutes :D)
Applying that to this article implies this is just correlation, those who start smoking weed at a young age do it to cope with other traumas in their life, but they never deal with the trauma so move on to other coping mechanisms.