Comorbidity of mental disorders and substance use: a brief guide for the primary care clinician
8.3 Major clinical issues with personality disorders and cannabis/ hallucinogen use
- People with personality disorders display more symptoms of cannabis use disorders than those who do not have a personality disorder.
- Advice regarding cannabis usage in these disorders depends on the degree of dysfunction associated with use.
- In the absence of other proven forms of treatment, CBT is, at present, the most widely employed form of treatment for cannabis use.
8.3.1 Effects of cannabis and other hallucinogens on personality disorders
- Conduct disorder in adolescence increases the risk of initiating marijuana use(320).
- Age of first use of cannabis is earlier in people with personality disorders compared to whose without personality disorders(320).
- People with personality disorders display more symptoms of cannabis dependence than those who do not have a personality disorder(320).
- Symptoms associated with cannabis dependence increase over time in those with personality disorders(320).
8.3.2 Interactions between cannabis and other hallucinogens and therapeutic agents for personality disorders
- Cannabis can exacerbate the sedative effects of carbamazepine, lithium and sodium valproatex.
- Cannabis can exacerbate the sedative effects of antidepressants such as tricyclicsx.
- LSD may induce a serotonin syndrome (Appendix 1); therefore, caution should be exercised when prescribing SSRIs or MAO-Ix(127).
- Cannabis and antidepressants are metabolised by CYP 450 enzymes which may result in the inhibition or induction of either drug group. Therefore, individuals should be monitored closely to ensure outcomes are appropriatex.
8.3.3 Management approaches to comorbid personality disorders and cannabis use
- Advice regarding cannabis use for people with these disorders depends on the degree of dysfunction associated with use.
- Overall approach depends on the person's readiness for change.
- Abstinence from cannabis is a difficult goal to achieve in cannabis dependent people(128).
- In the absence of other proven forms of treatment, CBT is, at present, the most widely-employed form of treatment for cannabis use****(128).