- A history of preexisting psychiatric condition, especially severe depression, or a history of severe psychiatric disorder, such as major psychoses, suicidal ideation and/or suicidal attempt are excluded. Severe depression would include the following: (a) subjects who have been hospitalized for depression, (b) subjects who have received electroconvulsive therapy for depression, or (c) subjects whose depression has resulted in a prolonged absence of work and/or significant disruption of daily functions. Subjects with a history of mild depression may be considered for entry into the protocol provided that a pretreatment assessment of the subject's mental status supports that the subject is clinically stable. The Investigator will formulate a management plan for each of the subjects that will become a part of the subject's medical record. The management plans may be developed in conjunction with a health care professional trained in psychology. For these subjects, the Investigator will review the subject's mental status at every visit.