Identifying risk factors for suicide research and prevention

Abstract

Research on risk factor for suicidal behaviors has been broadly conducted to enhance knowledge of suicide prevention. However, there are still challenges for risk factor research. Four major research gaps have been identified: (1) uncertain effectiveness of the population approach versus the high-risk approach for suicide prevention; (2) lack of a valid and convenient Chinese-version screening tool for the severity of suicidal ideation among adolescents; (3) demand for testing the prospective associations of risk factors with suicidal ideation using a longitudinal designed population-based sample; and (4) necessity of pathway analysis to explore and confirm how risk factors interact with each other and lead to suicidality. This thesis aims to address these gaps through a combination of five studies. Study 1 introduces an illness and death model to suicide prevention research. Elasticity and sensitivity analyses were performed. The findings revealed that the control of suicide incidence among the healthy population is the most effective prevention strategy whereas treatment of mental illness appears to be the least effective approach to suicide prevention. Study 2 validates the psychometric properties of the Chinese versions of Reynolds’s Suicidal Ideation Questionnaire (SIQ) and Suicidal Ideation Questionnaire Junior (SIQ-JR, a short version of the SIQ) in a sample of Hong Kong adolescents. A short, four-item version of the SIQ-JR has been suggested as an alternative to the SIQ and the SIQ-JR. Study 3 identifies the history of psychiatric treatment, depression, anxiety, hopelessness, unstable marital status, poor economic circumstance, and a recent death of a first-degree relative as significant risk factors for the incidence of suicidal ideation. The associations of change in risk factors with the development of suicidal ideation have been tested. There are gender and age differences in the patterns of such associations. Study 4 focuses on psychological factors associated with the first-ever incidence of suicidal ideation. Psychological factors have been detected generally to differ in their associations with the incidence and persistence of suicidality. The idea that depression partially mediates the effect of average life distress on the persistence of suicidal ideation has clinical value. Study 5 introduces and tests a stressor and illness model as a theoretical framework reference for future risk factor research. Risk factors are classified into stressor, illness, and pattern factors. Both the simple and complex models are tested. Evidence supported the proposed mediating role of mental disorders between negative life events and severity of suicidal ideation. A gender-specific pattern of associations between stressors, illness, and severity of suicidal ideation has also been detected. This thesis has made substantial theoretical, psychometric, and empirical contributions to the existing knowledge of suicide research.