To assess the prevalence of metabolic syndrome and its association with sociodemographic, clinical and lifestyle variables among Australian patients with a variety of psychiatric disorders.

Cross-sectional study of patients attending a public mental health service in Western Australia between July 2005 and September 2006.

Patients who were aged 18–65 years; diagnosed with schizophrenia, schizoaffective disorder, bipolar disorder, major depressive disorder with psychotic symptoms, drug-induced psychosis or borderline personality disorder; and currently taking at least one antipsychotic drug for a minimum of 2 weeks.

Prevalence of metabolic syndrome diagnosed with International Diabetes Federation criteria; fasting blood glucose and lipid levels; sociodemographic and lifestyle characteristics.

Of 219 patients invited to participate, 203 agreed and had complete data. Prevalence of metabolic syndrome was 54% overall, and highest among patients with bipolar disorder or schizoaffective disorder (both 67%), followed by schizophrenia (51%). Sociodemographic variables, including age and ethnic background, were not significantly associated with metabolic syndrome, but a strong association was seen with mean body mass index. Other cardiovascular risk factors, such as smoking and substance misuse, were common among participants.

Prevalence of metabolic syndrome in this population was almost double that in the general Australian population, and patients with schizophrenia had a prevalence among the highest in the developed world. Prevalence was also high in patients with a variety of other psychiatric disorders.