BACKGROUND: Shortly after phenothiazines were introduced, they were found to elevate serum triglyceride and total cholesterol levels. During the past decade, an increasing body of literature has also documented this effect in atypical antipsychotics. Previous studies of antipsychotic-associated hyperlipidemias are based on clinical samples, mostly from case series. We studied the prevalence of hyperlipidemia in subjects who did and did not take antipsychotic medication in a prospective, general population-based birth cohort. METHOD: The study sample consisted of 5654 members of the unselected Northern Finland 1966 Birth Cohort who participated in the 1997-1998 clinical examination at 31 years of age. Blood samples were taken after an overnight fast, and serum total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglyceride levels were determined. Health habits and other possible correlates for hyperlipidemia were assessed using a questionnaire. The sample was analyzed in 4 categories according to use of antipsychotic medication: (1) atypical, (2) typical, (3) atypical and typical (for the 3 antipsychotic categories, total N = 45), and (4) no antipsychotic medication (N = 5609). Nonparametric tests and multiple logistic regression analysis were used to measure the effect of antipsychotics on serum lipids. RESULTS: High lipid levels were found in persons treated with both atypical and typical medication (mean total cholesterol = 233 mg/dL, mean triglycerides = 163 mg/dL). Mean total cholesterol and triglycerides were also high in subjects who used only typical medication (215 mg/dL and 148 mg/dL, respectively). The prevalence of hypercholesterolemia, high LDL cholesterol, and hypertriglyceridemia was high in persons using antipsychotic medication (31.1%, 20.0%, and 22.2%, respectively) compared with persons not using such medication (12.2%, 10.2%, and 7.0%, respectively). After we adjusted for risk factors for hyperlipidemia (sex, diet, waist circumference, physical exercise, smoking, and alcohol consumption), the results of logistic regression analysis showed that in persons treated with antipsychotic medication the risk of hypercholesterolemia was 2.8 (95% CI = 1.4 to 5.6); of hypertriglyceridemia, 2.3 (95% CI = 1.0 to 5.4); and of high LDL cholesterol, 1.6 (95% CI = 0.7 to 3.5). CONCLUSION: Lipid levels in subjects who used both atypical and typical medication and those who used only typical medication were high even in young age. As these persons are at special risk of hyperlipidemia, their lipid levels should be regularly monitored, and a cholesterol-lowering diet, as well as medication, should be considered. The results indicate an elevated risk of hyperlipidemia in persons using antipsychotic medication independent of the other risk factors assessed.