"A chart review of patients diagnosed with PTSD who were referred to a private psychiatric clinic suggests that the synthetic cannabinoid, nabilone, has beneficial effects beyond its official indication in regard to abolishing or greatly reducing nightmares that persisted in spite of treatment with conventional PTSD medications.
"The subjects concomitantly received nabilone in addition to the one or more psychiatric medications that they were already taking for 2 years or more. No tolerance to nabilone was observed among the patients. This may indicate its potential longer-term safety and efficacy.
"The author recognizes the limits of this study (e.g., there was no placebo control, the measurements were limited to subjective reports to nightmare changes, the study was on a small number of patients, and there was a selective bias by nature of referrals to a specific clinic from which the patients were selected). Nonetheless, on the basis of these retrospective findings, nabilone appears to be a significant treatment for nightmares in the PTSD population."
Fraser, George A., "The Use of a Synthetic Cannabinoid in the Management of Treatment-Resistant Nightmares in Posttraumatic Stress Disorder (PTSD)," CNS Neuroscience & Therapeutics (Hoboken, NJ: Wiley-Blackwell, Winter 2009), p. 87.