What initially primes an addictive disorder is not necessarily what maintains the disorder. Addiction is, in principle, behavioural, with positive reinforcement from neurochemical effects (e.g. a dopaminergic surge following reward) that are linked to drug-contingent memories driving pervasive drug craving and dysphoria [154]. Most individuals report using cannabis to get “stoned” or “high”, which involves sensations including general euphoria, heightened awareness, relaxation and pleasure [30, 63]. Biologically, cannabis stimulates CB1Rs, which alters dopamine function, of which is associated with one’s positive hedonic experience [112]. Because of these intoxication characteristics, the user’s psychological state becomes associated with the drug and context of use, priming a cycle of positive reinforcement and incentive salience [88]. These neurobiological and psychological changes mark the initial process in drug use and addiction, with mesocorticolimbic dopamine transmission playing a key role alongside other neurotransmitter activations in regions including the ventral tegmental area, nucleus accumbens and frontal cortex [88]. The reported “high” induced by cannabis may explain what primes this addiction.
