The purpose of this study is to develop the weight management program, which is combined with healthy diet, proper physical exercise, and behavior modification, related to patient's quality of life. The patients groups are in routine practice with 5-20 mg olanzapine. The study results may be utilized for patients who have gained weight on olanzapine and also other antipsychotic drugs.

Inclusion Criteria:

• Male and female patients between the ages of 18 and 65 years (inclusive)
• Subjects must meet the DSM-IV criteria for schizophrenia, schizoaffective disorder, or schizophreniform disorder
• Subjects must have been treated with olanzapine (5 to 20 mg/day) for at least 12 weeks prior to study entry and who experienced a weight gain of greater than or equal to 7% of body weight during olanzapine treatment

Exclusion Criteria:

• Treatment with an injectable depot neuroleptic 14 days before visit 1
• Subjects with an PANSS score greater than 70
• One or more seizures without a clear and unresolved etiology
• Known diagnosis of DSM-IV substance dependence (except nicotine and caffeine) within the past 2 months, which in the opinion of the investigator is affecting the diet and/or weight of the subject
• As a result of liver function test, ALT/AST ranges are shown twice the upper limit of the normal reference range