Are the SSRIs that are the culprit in these shootings popular drugs of abuse? It seems that the shooters had prescriptions.
They aren't recreational drugs as such. But someone who wants to "Trip" can certainly do so by taking too high a dosage. Really most people, heck even most doctors don't know that an adverse reaction of SSRI's can cause major psychotic episodes much like LSD. It's not Tin Foil Kookery there are some very respectable source on this. Research Serotonin Syndrome. I've seen it happen and six doctors at two hospitals not catch it. In most cases I'm guessing the person isn't violent. But what they are hallucinating is their reality.
I've made some post on the thread that might give you some better understanding of how it can happen and why. The thing of it is patients and families are not being educated about the potential for an adverse reaction. Worse than that the adverse reaction symptoms when seen by doctors is often misunderstood as a deeper mental illness and they increase the darn dosage. I showed an article to a doctor treating my wife and at first he said that's pure rubbish. I said read the authors name of who wrote it. It was his Pharmacology Professor as this was at a university hospital. It doesn't have to be a person with serious issues this can happen too. Antidepressants are used for example to help people stop smoking, PMS, mild depression, etc.