Effects of an Autobiographical Self-Efficacy Training on Precursors of Suicidal Thoughts: A Three-Group Experimental Study

Background. Suicidal thoughts and behaviours (STBs) remain a substantial global burden, whileintervention effects are modest. Novel mechanistic interventions are needed. Enhancing self-efficacy viavivid recall of personal memories is a promising approach. This study tested an autobiographical self-efficacy training as an intervention for STBs by examining its effects on STB precursors, namelyperceived burdensomeness and thwarted belongingness, in a healthy sample. Methods. Participants (n =105, 72% female) were randomized to a self-efficacy memory recall, a neutral memory recall, or a notraining group. Participants completed an interpersonal stress task designed to elicit perceivedburdensomeness and thwarted belongingness, assessed via ecological momentary assessments six timesduring the task, alongside heart rate variability (HRV) recordings. Linear mixed models evaluated trainingeffects. Results. Training did not significantly affect task-specific perceived burdensomeness (no trainingvs. self-efficacy: b = −0.01, 95% CI [−0.28, 0.26]; neutral vs. self-efficacy: b = 0.09, 95% CI [−0.18, 0.36]) orthwarted belongingness (no training vs. self-efficacy: b = 0.21, 95% CI [-0.05, 0.48]; neutral vs. self-efficacy: b = 0.22, 95% CI [-0.04, 0.48]), though the neutral group showed a greater increase in desire todrop out (b = 0.33, 95% CI [0.02, 0.63]). Post-experiment global scores indicated reduced perceivedburdensomeness in the self-efficacy group relative to both controls (no training: b = 1.42, pHolm = .022,95% CI [0.39, 2.45]; neutral training: b = 1.31, pHolm = .026, 95% CI [0.29, 2.33]) and reduced thwartedbelongingness relative to the no training group (b = 1.27, pHolm = .010, 95% CI [0.45, 2.09]). HRV analysesrevealed higher low frequency power in the self-efficacy group during later stages of the task (neutralvs. self-efficacy: b = −0.42, pHolm = .032, 95% CI [−0.70, −0.14]; no training vs. self-efficacy: b = −0.39, pHolm= .038, 95% CI [−0.67, −0.11]). Conclusion. Autobiographical self-efficacy training positively influencedglobal STB precursors and stress-related HRV, suggesting it is a promising candidate intervention forsuicide prevention. Further evaluation in clinical samples is warranted.