The association between cannabis use and anxiety disorders is best explained by the self-medication hypothesis, in which anxiety predisposes individuals toward cannabis use, rather than cannabis use causing anxiety disorders. A systematic review of the literature found that while some studies report no correlation, a meta-analysis of 15 studies showed a modest correlation between anxiety and cannabis use (odds ratio 1.24), and a meta-analysis of 13 studies showed a stronger correlation between anxiety and cannabis use disorder (odds ratio 1.68). Causal interpretations and the common factor theory lack substantial support.
People with HIV often develop cognitive problems linked to disrupted fronto-striatal brain circuits, which are also affected by cannabis. HIV transgenic rats, which model HIV-associated neurocognitive disorder, showed a significant prepulse inhibition deficit compared to healthy controls, mirroring the sensorimotor gating impairment seen in people with HIV. Acute treatment with THC (1 and 3 mg/kg) reduced prepulse inhibition in control rats but not in HIV transgenic rats, indicating a relative insensitivity to THC's disruptive effects on fronto-striatal function. Cannabidiol (1, 10, and 30 mg/kg) had only minor, genotype-independent effects on prepulse inhibition. This reduced sensitivity may help explain higher cannabis use rates among people with HIV.