Chunk #38 — Conceptualizing Problematic Cannabis Use in Mental Illness: Addiction Vulnerability versus Self-Medication Hypothesis — Addiction Vulnerability Hypothesis Reconceived: Reconciliation with the Allostasis Model
Addiction vulnerability is described as the genetic, neurobiological and environmental factors that predispose an individual to develop substance use disorder. In individuals with comorbid mental illness and CUD, there is some evidence for a shared vulnerability. Mental illness, however, may also be a vulnerability factor itself, as it primes an individual to seek self-medication (Figure 1). Specifically, when an individual lacks protective self-regulatory abilities to deal with emotional dysfunction, cannabis use may be used as a substitute in order to cope with one’s mental illness. Initial relief of one’s affective state may positively reinforce the behaviour, eventually leading to an allostatic state in which a neurobiological affect deficit is produced. This deficit leads to reward circuitry hypofunction and the aggravation of affective symptoms observed during withdrawal. Continued cannabis use influences negative reinforcement by temporarily relieving the distress caused by withdrawal symptoms and the neurobiological deficit. Moreover, the cannabis user is unaware of these processes, perceiving cannabis as a mode to attenuate symptoms. In other words, mental illness makes an individual vulnerable to potential reliance on cannabis as a coping strategy
