Actually, one of my advisers at one of the veterans hospitals I worked with was studying substance use and PTSD. To summarize her research, not mine, she found that sometimes when you take something like that, or alcohol, it can calm the symptoms in the moment, but then there can be bounceback anxiety. That's all I'll say on that.
What I will say is that in moving forward with any intervention, I really believe in collecting objective biological data. If we want to know if marijuana treats the symptoms, we can't just rely on self-reports. In the data I've collected, I've always asked the officers to self-report: how stressed they were, how confident they were about the situation, how well they were going to perform. Often those self-reports were opposite to what I saw going on in their bodies and in the mistakes they made.
It's the same with a program like road to mental readiness. I know there have been surveys about how beneficial it is for transferring to use of force by self-reports, but my concern is that they're saying these things because they want to appear well in the organization. When I've actually spoken with the use-of-force first responders, with the very macho attitude among them, it's not taken as well as their surveys indicate.