It turns out that New Mexico was the first state to acknowledge post-traumatic stress disorder (PTSD) as a condition that could benefit from the use of medical cannabis.
For a long time there were no published studies, other than a few case reports on the effects of CBD upon PTSD symptoms.
There was a study in 2014 that set out to statistically analyse data on PTSD, this study bought together 80 psychiatric evaluations of patients applying to the New Mexico Medical Cannabis Program from 2009 to 2011. It would seem that the results showed over a 75% reduction in symptoms when patients were using cannabis.
So, it does seem that patients with PTSD, in many cases, would experience improvements in their symptoms when using cannabis.