I don't think the problem is so much the guns as the culture of violence.

[Jackpine Radical]

88. OK, I'm sort of an environmental-genetic interactionist

when it comes to theories like this. That is, one may have some degree of genetic susceptibility to a behavioral pathology, but it may take some particular sort of events to bring the pathology into phenotypic expression.

OCD is essentially an anxiety disorder in which one binds one's ambient anxiety into the obsessions/compulsions. There is fairly good reason to believe that there is a substantial genetic component to anxiety--an anxiety-proneness, if you will. But only if the individual has certain types of experiences would you get the actual anxiety disorder. As to whether the anxiety disorder expresses as OCD or something else, that may not be easily predicted. Again, maybe the way the anxiety manifests may be partly genetically determined, for all I know.

Incidentally, there have been fMRI studies showing that cognitive-behavioral therapies are about equal in effect to medications such as Anafranil in normalizing brain activity in OCD patients. The changes in brain activity were accompanied by remission of the OCD symptoms.

As always, of course, assuming your OCD hypothesis has merit, there are going to be a lot more OCD cases than there are mass murderers.