In this clinical trial, a minimal dose of bexarotene (Targretin, 75 mg/day) or fenretinide 5 mg/day or placebo will be added for 8 weeks to the stable ongoing antipsychotic treatment of 90 schizophrenia patients. Participants will be assessed at baseline and after 2, 4 and 8 weeks of treatment. A battery of research instruments will be used for assessment of efficacy and safety (psychopathology, and side effects). In addition, cholesterol and triglyceride levels, liver and thyroid function tests and a blood cell count will be monitored at baseline and during therapy.
