Emerging observational and early clinical evidence suggest that cannabis (marijuana) may have the potential to reduce or ameliorate a number of symptoms experienced by those with PTSD, including sleep difficulty and anxiety. Indeed, some evidence has suggested that delta-9-tetrahydrocannabinol (THC) may serve to reduce nightmares among those with PTSD, while other studies have shown anxiolytic effects of cannabidiol (CBD). However, there have been no randomized controlled trials of cannabis, in any form, for PTSD.