Several studies have examined the efficacy of cannabis in treating post-traumatic stress disorder (PTSD). Cannabidiol (CBD) has been shown to help mitigate symptoms that are strongly associated with PTSD, including anxiety, nightmares, and insomnia, with very few adverse effects.
Tetrahydrocannabinol (THC), however, has a more difficult relationship with PTSD.
An observational study (Wilkinson et al. (2015)) involving 2276 United States Veterans found that THC-rich recreational cannabis use was associated with violent behavior, drug use, alcohol use, and PTSD symptom severity. Other studies (Greer et al. (2014), Roitman et al. (2014)) found that THC-rich cannabis use reduced symptom severity, particularly symptoms of anxiety and hyperarousal.
Research has shown that PTSD is associated with dysfunction within the corticolimbic region, which is responsible for responding to external threats, processing fear, and emotional regulation. Research has also shown that there is a significant concentration of cannabinoid (CB1) receptors in the corticolimbic system, which includes the amygdala, hippocampus, and portions of the prefrontal cortex, and that THC is a potent CB1 agonist. Researchers have theorized that the activation of these receptors with THC can mitigate the corticolimbic dysfunction associated with PTSD (most notably hyperarousal as characterized by hyperactive amygdala function).
Researchers from Wayne State University in Detroit (Rabinak et al. (2020)) recently tested this hypothesis in a randomized, double-blind, placebo-controlled study and published their findings in the Journal of Psychopharmacology. Among individuals with PTSD, they found that low doses of THC did have anxiolytic effects and that it ameliorated dysfunction in the amygdala, medial prefrontal cortex, and adjacent rostral cingulate cortex.
They concluded: “These preliminary data suggest that THC modulates threat-related processing in trauma-exposed individuals with PTSD, which may prove advantageous as a pharmacological approach to testing stress- and trauma-related psychopathology."
Read the study here.