Understanding Suicidal Ideation in Psychiatric Inpatients: The Roles of Interpersonal Needs and Experiential Avoidance

Depression is a significant risk factor for suicidal ideation, yet the mechanisms underlying this relationship remain unclear. Experiential avoidance and interpersonal needs, particularly perceived burdensomeness and thwarted belongingness, have been proposed as key mediators, but their relative roles in psychiatric inpatients are not well established. The objective of this study is to investigate whether experiential avoidance and interpersonal needs mediate the relationship between depression and suicidal ideation among psychiatric inpatients. This cross-sectional study included 151 psychiatric patients aged 18 years or older. Inclusion criteria were defined as recent suicide attempts accompanied by ongoing suicidal ideation or significant suicidal ideation. Data were collected using the Sociodemographic Form, Hospital Anxiety and Depression Scale, Acceptance and Action Questionnaire, Beck Scale for Suicide Ideation, and Interpersonal Needs Questionnaire with two subfactors: Perceived burdensomeness and thwarted belongingness. All measures showed statistically significant correlations with each other. The parallel three-mediator model further highlighted that the mediating role of perceived burdensomeness was more prominent than that of experiential avoidance, whose indirect effect alone was not significant. The results of this study may suggest that perceived burdensomeness is key to linking depression to suicidal ideation. Therapeutic approaches that strengthen social connectedness and reduce interpersonal distress may be particularly effective for managing suicidal ideation in psychiatric inpatients.