Homocysteine levels in first-episode, drug-naïve patients with psychiatric disorders

Abstract A high homocysteine (Hcy) level is reportedly a risk factor for schizophrenia, depression, bipolar disorder, and other psychiatric disorders. The purpose of this study was to examine Hcy levels in first-episode, drug-naïve inpatients with psychotic symptoms and a diversity of psychiatric diseases to further investigate the association between Hcy levels and psychiatric disorders. In this study, we enrolled 247 psychiatric patients, aged 18–40year. Seventy-five were diagnosed with schizophrenia, 48 with acute and transient psychotic disorders, 36 with manic episodes with psychosis, 32 with major depressive episodes with psychosis, and 56 healthy controls. Serum Hcy levels were measured by enzyme cycle method. Concentration of Hcy levels > 15 µmol/L was defined as hyperhomocysteinemia. Hcy levels were significantly higher in first-episode and drug-naïve psychotic patients compared to healthy controls (F = 12.778, P < 0.001). In the psychiatric disorder groups, Hcy levels were significantly higher in males and females (P < 0.05) in schizophrenia, acute and transient psychotic disorder, and major depressive disorder, but not in mania (P > 0.05). However, serum Hcy levels were not significantly different among the psychiatric disorder groups (F = 1.549, P = 0.227). The prevalence of hyperhomocysteinemia was 37.3% for schizophrenia, 45.8% for acute and transient psychotic disorders, 66.7% for manic episodes with psychosis, and 37.5% for major depressive episodes with psychosis. Hyperhomocysteinemia was more frequent in manic episodes with psychosis than in the other groups (χ2 = 10.026, P = 0.018). Moreover, binary logistic regression showed that male sex was an independent risk factor for hyperhomocysteinemia (OR = 6,577, 95% CI = 3.398–12.731, P < 0.001). These results suggest that first-episode, drug-naïve patients with the psychiatric disorders studied here have higher Hcy levels than does the general population, and those at greatest risk are men. However, we observed no differences in Hcy levels across different psychotic disorders. It has been suggested that elevated Hcy level contributes to the pathogenesis of psychiatric disorders, and our results clarify that it is likely an unspecific risk factor for psychiatric disorders generally.