This is one of the side effects of ptsd that can make a big difference, since sleep really is so important. Mine is more of a hypervigilance (I can almost be asleep and then hear a sound and all senses are in overdrive, so usually I just get up and patrol the perimeter of the house and check locks/doors/camera systems), but many of my buddies drank themselves to sleep every night. Most of them have switched to MJ and swear it's the best thing ever for them vs alcohol.

As a side note, I also think MJ counts as a nootropic when used properly, and I often think about Carl Sagans Mr. X article about it in this light, in the sense that a different perspective can help you solve issues or think about issues in a different way than you might have otherwise. This is why I highly suggest that people trying MJ try to be productive while on it instead of just (read: only) vegging.