The FBI’s definition of a “mass murder” specifies a minimum of four deaths, not including the murderer himself, in a short period of time. A lot of these get into the news, particularly if (1) firearms are involved and (2) the killer belongs to a group disfavored by politicians and news media. Blaming the weapons is fatuous — when I was in the Army, we had literally hundreds of guns on hand, and not one of them ever broke loose — which means there might be something else involved:
SSRIs have a risk of increasing violence in patients, even in patients who have no previous history of violence or aggression before taking the medication.
This risk of violent behavior, both to the individual taking the medication and those around them, is so significant, it has led to the FDA mandating a black box warning on all SSRI medications. These black box warnings are designed to provide information and draw attention to the fact that the medication has serious and life-threatening risks.
As of 2004, all antidepressants in the U.S. are labeled:
“Anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia, hypomania, and mania have been reported in adult and pediatric patients being treated with antidepressants for major depressive disorder as well as for indications, both psychiatric and nonpsychiatric.”
This of course does not mean that every mass shooter was driven to it by Prozac — Elavil, which I take, is older than God and has no black-box warnings at all — but given the American tendency to treat antisocial activity first with drugs, this is an area that probably needs more attention before the next person tries to shoot the whole day down.