Testing the predictions of the interpersonal-psychological theory of suicide in a sample of female cancer patients

Abstract Objectives Individuals suffering from cancer have a heightened risk of suicide; thus, understanding suicide-related thoughts and behaviors is key to identifying vulnerable patients. The interpersonal theory of suicide (IPTS) provides a comprehensive framework for examining suicide risk factors and has been validated across a range of samples. This study aimed to evaluate the applicability of IPTS in a group of female cancer patients. Methods This study was registered with the German Clinical Trials Register (DRKS00020477; registered on June 30, 2020). In this study, we tested three major hypotheses formulated by the IPTS, using a sample of 199 female cancer patients. Results As predicted by the IPTS, heightened levels of thwarted belongingness (TB) and perceived burdensomeness (PB) were indicative of elevated levels of passive suicidal ideation (SI). Furthermore, the interaction of TB, PB, and hopelessness was predictive of active SI. However, contrary to theoretical assumptions, the findings indicate that an increased fear of death was associated with higher suicidal intent. Limitations The cross-sectional design curtails the affirmation of hypotheses pertaining to causality. Rather than considering a measure of hopelessness specifically related to PB and TB, a general measure was employed. Additionally, the recruitment phase of the study coincided with the onset of the global SARS-CoV-2 virus pandemic, which might have impacted the results. Conclusions Even though the three hypotheses were only partially verified, the IPTS provides a beneficial framework for health professionals who are caring for patients with cancer. Longitudinal studies are encouraged to further validate the theory and bolster its application in understanding suicidal behavior.