The efficacy of nabilone, a synthetic cannabinoid, in the treatment of PTSD-associated nightmares A preliminary randomized, double-blind, placebo-controlled cross-over design study.
Investigate the efficacy of nabilone capsules (NAB) in reducing the frequency and intensity of nightmares in subjects with PTSD. Canadian male military personnel with PTSD, who despite standard treatment continued to experience trauma-related nightmares, received double-blind treatment with 0.5mg NAB or placebo (PBO), and then titrated to the effective dose (nightmare suppression) or reaching a maximum of 3.0mg. Subjects were followed for 7 weeks and then, following a 2-week washout period, were titrated with the other study treatment and followed for an additional 7 weeks. The modified intent-to-treat (mITT) population, which included all treated subjects that met inclusionexclusion criteria, was analyzed. Ten subjects were included in the mITT population. The mean reduction in nightmares as measured by the CAPS Recurring and Distressing Dream scores were -3.6 ± 2.4 and -1.0 ± 2.1 in the NAB and PBO groups, respectively (p0.03). Mean global improvement as measured by the Clinical Global Impression of Change (CGI-C) was 1.9 ± 1.1 (i.e. much improved) and 3.2 ± 1.2 (i.e. minimally improved) in the NAB and PBO groups, respectively (p0.05) Five out of 10 (50%) were much improved on NAB versus 1 out of 9 (11%) on PBO. Results for the General Well Being Questionnaire (WBQ) were 20.8 ± 22 and -0.4 ± 20.6 in the NAB and PBO groups, respectively (p0.04). The proportion of subjects who experienced a treatment-related occurrence of adverse events was 50% in the NBO group and 60% in the PBO group. No event was severe nor resulted in a drop-out. This study is registered with Health Canada. In this small sample NAB provided significant relief for military personnel with PTSD, indicating that it shows promise as a clinically-relevant treatment for patients with nightmares and a history of non-response to traditional therapies. These findings need to be replicated in a larger cohort. There is a need for further exploration of the effect of nabilone on other symptoms of PTSD such as re-experiencing, hyper vigilance and insomnia.