However,they maintain the Russians were involved in this election... Amazing that. I mean his first wife is Ivanka. Ivanka is as Russian a name as one could ever want, even if they pretend it's Polish.

Mental illness could be an underlying cause, together with loads of prescription meds, as you rightly mentioned, to drive a guy to mass murder, if so inclined of course. I favour suicide but not everyone thinks this way.
Then, to confuse things just a tad, John Rapaport wrote that this whole shooting, like 911, was part fake and part truth. There is another lot, going by the name aim4truth, claiming that Obama tried to make it legal for the American government to use propaganda against its own citizens, that 911 was fake, and that most of this mass shooting as well as the one in Orlando is fake and they back it up very well. This opens a whole new world inside the parallel one we live in. Seemingly.