Hi budsmoker,
Thanks for your comments. Your point about sativa and indica strains is a good one, and something I didn't know much about until I started posting on these online forums. From all of the comments I have read it does appear that sativa induces anxiety more often than indica. However, in all of the research that I have done, not one scientific study has even mentioned indica....it is all sativa. This is something I would lke to rectify when I do my PhD. It appears that the academics have no idea about the effects of different strains.

So, what do I hope to find out? Well at the moment most of the research has been focused on the THC/CBD ratio. As you probably know high conentrations of THC have been shown to produce anxiety in clinical trials, whereas high concentrations of cannabidiol (CBD) appear to produce a calming effect in users. This is why I have asked questions about what parts of the plant you smoke (as bud/heads have a higher THC to CBD ratio than leaf).

I have also asked a range of questions such as your motivation for use, when you first started smoking it, how much you smoke and how often you smoke it, your levels of intoxication, the environment that you smoke it in, the effect it has on you, family history of anxiety and depression and your current levels of anxiety and depression. All of these variables will eventually be analysed where I will be looking for patterns and relationships between variables.
At the moment very little is actually known about the relationship between cannabis use and anxiety. The fact that cannabis can induce anxiety in some users, and reduce symptoms in others, seems to have placed this type of research in the 'too hard' basket. Hopefully the information gathered in my survey will eventually help generate more research, and in turn help to provide a better understanding of the effects of cannabis.
Cheers,
Matt