"In studies of first-episode bipolar patients, investigators at McLean Hospital, the University of Pittsburgh, and the University of Cincinnati Hospital found that at least one-third had used marijuana or some other illegal drug prior to their first manic or psychotic episode.10 This substance abuse, the University of Cincinnati investigators concluded, may "initiate progressively more severe affective responses, culminating in manic or depressive episodes, that then become self-perpetuating."11 Even the one-third figure may be low; in 2008, researchers at Mt. Sinai Medical School reported that nearly two-thirds of the bipolar patients hospitalized at Silver Hill Hospital in Connecticut in 2005 and 2006 experienced their first bout of "mood instability" after they had abused illicit drugs.12 Stimulants, cocaine, marijuana, and hallucinogens were common culprits. In 2007, Dutch investigators reported that marijuana use "is associated with a fivefold increase in the risk of a first diagnosis of bipolar disorder" and that one-third of new bipolar cases in the Netherlands resulted from it.13"