Transcultural differences in suicide attempters: analysis on a high-risk population of patients with schizophrenia or schizoaffective disorder

The aim of the study was to investigate transcultural differences between schizophrenia spectrum disorder patients who did or did not attempt suicide. DSM-IV schizophrenia (N=609) or schizoaffective disorder (N=371) patients who participated in the multicentre International Suicide Prevention Trial (InterSePT) were studied. Patients were sub-divided into 5 groups according to the different geographical regions of recruitment: North America (NA), Europe (EUR), East Europe (EEUR), South Africa (SAf), and South America (SA). The main lifetime clinical variables were compared, within each group, between attempters and non-attempters. The presence of comorbid substance abuse disorder and smoking was associated with suicide attempts in all the geographical groups considered (NA: chi(1)(2)=7.575, p<0.01 and chi(1)(2)=69.549, p<0.0001; EUR: chi(1)(2)=55.068, p<0.0001, and chi(1)(2)=48.431, p<0.0001; EEUR: chi(1)(2)=164.628, p<0.000, and chi(1)(2)=5.127, p<0.01; SA: chi(1)(2)=30.204, p<0.0001 and chi(1)(2)=11.710, p=0.001) except for SAf. For the other clinical variables various differences were found across the different groups. Variables related to suicide behavior were similar across the five groups investigated, with differences only in the age at the first suicide attempt (earlier in the NA sample) and the number of lifetime suicide attempts (higher in the NA sample). Results from this study show that, while some suicide-related clinical characteristics in schizophrenia patients are consistent worldwide suggesting the influence of stable biological traits, other variables may vary across different geographical areas suggesting environmental influences.