Mental & Emotional Health A Lesson from Mary Kennedy's Death By Adprime Admin article By Judy Kirkwood Mary Richardson Kennedy’s death could not have been unanticipated. According to the National Institute of Mental Health, more than 90 percent of people who die from suicide have the risk factors of depression and other mental disorders, including substance abuse disorders. Any knowledgeable health provider versed in dual diagnosis could have told the Kennedy and Richardson families that it was not a good idea for Mary to be living alone and to have total responsibility for her finances and health.