Assessing the risk for suicide in schizophrenia according to migration, ethnicity and geographical ancestry

Abstract

Background: Suicide is a leading cause of mortality among those afflicted by schizophrenia. Previous studies demonstrated that the stressors associated with immigration may lead to an onset of schizophrenia and suicide separately in susceptible individuals. However, no studies have shown whether immigration may lead to suicidal behaviour for individuals with schizophrenia. Our study proposes that an individual's geographical ancestry, ethnicity or migration status may be predictive of suicide risk in schizophrenia.

Methods: In a sample of 276 participants with schizophrenia spectrum disorders, we conducted cross-sectional assessments to collect clinical information. Self-identified ethnicity and suicide history were collected through self-report questionnaires and interview-based scales. Ancestry was identified using 292 genetic markers from HapMap. Migrants were classified as those who immigrated to Canada during their lifetime. Using a regression analysis, we tested whether a history of migration, ethnicity or geographical ancestry were predictive of a history of suicide attempts.

Results: Our analysis failed to demonstrate a significant relationship between suicide history and migration, ethnicity or ancestry. However, ethnicity appears to be significantly associated with the number of psychiatric hospitalizations in our sample.

Conclusion: Ethnicity and migration history are not predictive of previous suicide attempts. Ethnicity may be an important demographic factor affecting access to mental health resources and frequency of hospitalizations.

Keywords: Ancestry; Ethnicity; Migration; Schizophrenia; Suicide.

Fig. 1

Multidimensional scale clustering according to the geographical ancestry using 292 SNP markers from the HapMap Phase II project

Fig. 2

STRUCTURE analysis of self-reported ethnicity of study participants and reference population from HapMap.1 = Study participants (n = 276); 2 (green) = Japanese and Han Chinese Asians (JPT + CHB) reference population (n = 90); 3 (red) = North/western Europeans from Utah (CEU) reference population (n = 60); 4 (blue) = Yorubans from Nigeria (YRI) reference population (n = 60)