Suicidal ideation in a non-clinical sample : cross-sectional and longitudinal relationships with minor stressors, depression, hopelessness and coping behaviour : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Psychology at Massey University
The intention of this study was to gain a greater understanding of the way minor stressors, depression, hopelessness and coping behaviour relate to suicidal ideation in a non-clinical sample. Little is known about the mechanisms through which minor stressors impact on suicidal ideation. This study examined the roles of depression and hopelessness as potential mechanisms through which minor stressors could influence suicidal ideation. The way a person copes with stress affects health outcomes but this has yet to be demonstrated with suicidal ideation. This study examined the influence coping behaviour has on the relationship between minor stressors and suicidal ideation. The mechanisms through which coping behaviour impacts on suicidal ideation are largely unknown. Therefore, the possibility that coping behaviour interacts with minor stressors to influence depression and hopelessness and thus suicidal ideation was investigated. The use of prospective research designs in the study of suicidal ideation is rare, but longitudinal validation of cross-sectional findings is important in furthering our understanding. This study also examined whether the hypothesised relationships between current suicidal ideation and minor stressors, depression, hopelessness and coping behaviour extended to the prediction of further suicidal ideation. The subjects were 402 undergraduate university students who volunteered to complete measures of suicidal ideation, minor stressors, depression, hopelessness and coping behaviour on two occasions five months apart. The results showed that minor stressors, depression, hopelessness and emotion-focused coping were all correlated with suicidal ideation. Depression and hopelessness, however, were the best predictors of suicidal ideation. Depression was a better predictor than hopelessness, and also mediated the relationship between minor stressors and suicidal ideation. Emotion-focused coping interacted with minor stressors to modify their relationship with suicidal ideation and depression. In both cases the greater use of emotion-focused coping to deal with high levels of stressors, was associated with higher levels of suicidal ideation and depression. The findings for current suicidal ideation generally did not extend to the prediction of further suicidal ideation. Prior suicidal ideation proved to be the best predictor of later suicidal ideation. Concurrent levels of minor stressors, depression, hopelessness and coping behaviour were better predictors of further suicidal ideation than were their prior levels. The results suggest that depression is more important than hopelessness in predicting current suicidal ideation in non-clinical samples. Depression is the mechanism through which minor stressors influence current suicidal ideation and coping behaviour impacts on suicidal ideation through its influence on the relationship between minor stressors and depression. Further suicidal ideation appears to be influenced more by the concurrent states of minor stressors, depression, hopelessness and coping behaviour, than by their prior states. The implications of these results are discussed in relation to the development of an interactive model of suicidal ideation, and suggestions for future research are made.