“Some mass murderers, so deeply depressed, become schizophrenic or psychotic. Others suffer with severe anxiety and personality disorders. These are not rational people at the time of the murders even when their behaviors are calculated and decisive. Many of them are not legally insane but suffer from severe psychological dysfunctioning as a result of both chronic and acute stress.” Mental IllnessMurderersMass MurderCrime StatisticsEric W HickeyMass MurderersLegally Sane Book:Serial Murderers and their Victims Source: Serial Murderers and their Victims