- Evidence of current severe psychiatric disease, especially depression within one year of study entry. Severe psychiatric disease is defined as treatment with an antidepressant medication or a major tranquilizer at therapeutic doses for major depression or psychosis, respectively, within 12 months prior to study entry. Patients with a previous history of the following: a suicidal attempt, hospitalization for psychiatric disease, or a period of disability due to a psychiatric disease should be evaluated by a qualified Psychiatrist for study suitability prior to enrolment.