Identification of risk factors for suicidal ideation in patients with schizophrenia

Patients with schizophrenia have a high risk for suicide, and therefore, identification of risk factors for suicidal ideation (SI) may be helpful to reduce suicide rate. This study aimed to detect which clinical symptoms and biochemical parameters were most strongly associated with SI. A total of 174 patients and 35 healthy controls were enrolled in our study. Patients were evaluated by the Positive and Negative Syndrome Scale (PANSS), Scale of Assessment Negative Symptoms (SANS) and the Calgary Depression Scale for Schizophrenia (CDSS) for psychiatric and depressive symptoms, and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) for cognitive function. We examined the levels of prolactin (PRL) and metabolic parameters in all participants. Our results showed a significantly increased level of PRL in patients compared to the controls before (t = 10.414, P < 0.001) and after (F = 31.308, P < 0.001) covariates were controlled for. In addition, we found that patients with SI had significantly higher PRL levels than those without SI (t = 2.586, P = 0.011). And there were positive correlations between serum PRL levels (r = 0.194, P = 0.010), serum fasting triglyceride levels (TG) (r = 0.188, P = 0.013), and RBANS visuospatial skill subscores (r = 0.162, P = 0.036) and SI severity. Finally, the stepwise multiple linear regression analysis revealed that SI severity was significantly associated with PRL levels, fasting TG levels and RBANS visuospatial skill subscores. This study provides support that greater cognitive ability, specifically visuospatial skill, PRL and TG, may confer an elevated risk for more severe SI in schizophrenia patients.