Schizotypal personality disorder (SPD) is classified in DSM-V as a cluster A personality disorder. Cluster A personality disorders are described as odd or eccentric conditions. SPD is associated with significant disability and many psychiatric comorbidities. Several studies have shown that SPD and schizotypal traits are associated with suicidal ideation and behaviour. Suicide prevention interventions in individuals with SPD are impeded because (1) SPD is frequently not diagnosed; (2) SPD is difficult to treat; and (3) there are no guidelines for suicide screening or suicide prevention interventions in individuals with SPD. Suicide prevention in persons with SPD consists of (1) diagnosing SPD; (2) providing appropriate treatment for SPD; and (3) providing suicide screening and suicide prevention. Interventions aiming at reduction of depressive symptoms, improvement of self-esteem, and interpersonal skills may be effective at reducing suicide risk amongst individuals with SPD. Studies of suicidality in persons with SPD are needed and may be an important area of suicide research. It is to be hoped that future studies of the pathophysiology of suicidality in individuals with SPD will help to develop strategies for suicide screening and suicide prevention interventions in persons with SPD and improve suicide prevention in this challenging patient population.

The aim of the present study is to determine whether plasma bile acids (BAs) could be used as an auxiliary diagnostic biomarker to distinguish patients with schizophrenia from healthy controls. Seventeen different BAs were quantitatively measured in plasma of 12 healthy participants and 12 patients with schizophrenia. Then, the data were subjected to correlation and linear discriminant analysis (LDA). The concentrations of cholic acid (CA), taurochenodeoxycholic acid (TCDCA) and taurodeoxycholic acid (TDCA) were significantly decreased in plasma of the schizophrenia patients. Correlation analysis showed the concentrations of CA, TCDCA and TDCA were negatively correlated with schizophrenia. In addition, LDA demonstrated that combination of CA, TCDCA and TDCA with a classification formula could predict correctly classified cases and the accuracy of prediction was up to 95.83%. Combination of the three BAs may be useful to diagnose schizophrenia in plasma samples.