The investigators would like to know the association of gene polymorphisms and metabolic adversities in clozapine-treated patients with schizophrenia in Taiwan.

The atypical antipsychotics, such as olanzapine, risperidone, quetiapine, and ziprasidone, are effective in treating both the positive and negative symptoms in schizophrenia (Kelleher et al., 2002). However, atypical antipsychotics have been linked to several forms of morbidity, including obesity, hyperlipidemia, and type 2 diabetes mellitus (DM) (Bergman and Ader, 2005; Jin et al., 2004; Melkersson and Dahl, 2004). Compared with the general population, life expectancy in schizophrenic patients is shorter by as much as 20%, attributable to higher rates of suicide, accidental deaths, and natural causes such as cardiovascular disease and DM (Harris and Barraclough, 1998). Several studies have suggested that these metabolic abnormalities may lead to a greater vulnerability to cardiovascular disease and thus may contribute to the excessive mortality among schizophrenic patients.

Inclusion Criteria:

• fulfilled DSM-IV criteria of schizophrenia or schizoaffective disorder
• 18-65 year of age
• receiving clozapine for at least 6 months

Exclusion Criteria:

• diabetes mellitus patients

schizophrenia or schizoaffective disorder patients