Do the Constructs of the Interpersonal Psychological Theory of Suicide Mediate the Relationship between Depression and Suicidal Behaviour?

Abstract

AimThis research aims to investigate the effectiveness of the InterpersonalPsychological Theory of Suicide (IPTS) as a model for understanding and predicting the risk of three levels of suicidal behaviour: passive suicidal ideations (those experiencing no suicidal thoughts, occasional thoughts about suicide and passive suicidal plans), active suicidal thoughts (those experiencing occasional thoughts about suicide, passive suicidal plans and active suicidal plans), and potentially lethal suicide attempts (those experiencing passive suicidal plans, active suicidal plans and suicide attempts). The research questions were: 1) Do the IPTS constructs of Thwarted Belongingness (TB), Perceived Burdensomeness (PB) and Hopelessness (H) represent general predictors of mental health distress or are they specific predictors of suicidal risk?; 2) Do the IPTS constructs (TB, PB and H) remain important predictors of risk when compared with the more traditional, well established epidemiological (age, sex and relationship status) and psychopathological (depression and anxiety) risk factors already known to influence suicidal behaviour?; 3) Do the IPTS constructs (TB and PB) function as proximal risk factors (mediators) between depression and suicidal behaviour, (controlling for age, sex and relationship status)?; 4) Are the IPTS constructs (TB and PB) related to each other?; 5) Does hopelessness mediate the relationship between TB and PB?, and 6) Does the IPTS construct of AC help predict suicide attempts? Methods The study used a cross-sectional design to survey 254 participants from the general population, and deliberately targeted groups known to be at risk of suicide including people with mental health and developmental difficulties. Measures used included: The Suicide Behaviors Questionnaire-Revised (SBQ-R); The Interpersonal Needs Questionnaire (INQ-10); The Acquired Capability for Suicide Scale (ACSS-20), and The Hospital Anxiety and Depression Scale (HADS).Results Using linear and hierarchical regression, and sequential mediational analysis via the PROCESS macro, the results showed that: 1) TB and PB represented a model specific to suicidal risk rather than general mental health distress; 2) the IPTS constructs accounted for more variance in suicidal risk than socio-demographic factors (age, sex and relationship status) or mental health difficulties (depression and anxiety); 3) TB and PB were proximal factors in the relationship between depression and each of the three levels of suicidal behaviour; 4) TB and PB were related to each other and results established a statistical time ordering such that depression led to TB which caused PB which in turn led to the two more serious forms of suicidal behaviour; 5) hopelessness mediated the relationship between TB and PB and became an increasingly pervasive state of mind as the severity of suicidal behaviours increased; 6) eight items of the Acquired Capability for Suicide Scale (ACSS-20) were associated with suicidal risk, with: (i) a readiness to die (“I could kill myself if I wanted to”) being specifically associated with the transition from passive suicidal ideation to active suicidal thoughts and (ii) a readiness to die combined with a reduced fear of death (“I am not afraid to die”) significantly heightening the risk of experiencing potentially lethal suicide attempts. Conclusion Following an examination of the specificity of the IPTS framework, the results seem to suggest that its main components (TB, PB, Hopelessness and AC) could have a great deal of clinical utility in terms of: improving risk assessment, enhancing public and professional education about the causal nature of suicidal, and as the basis of a psychotherapeutic model to help improve the interpersonal wellbeing of people experiencing various forms of suicidal behaviour.

Date of Award	Apr 2021
Original language	English
Awarding Institution	Coventry University
Supervisor	Anthony Colombo (Supervisor), Eve Knight (Supervisor) & Georgia Niolaki (Supervisor)