Abstract
Repetitive thinking about the future plays a crucial role in adolescent suicide ideation, yet the specific forms of future-oriented repetitive thought that predict suicide ideation, and their psychological mechanisms, remain understudied. This study investigated how three dimensions of future-oriented repetitive thought predicted suicide ideation among treatment-seeking adolescents and whether depressive symptoms mediated the relationship. Adolescents (N = 119; ages 12-19) who presented to the emergency department or outpatient treatment with recent suicide ideation or attempts completed a measure capturing three dimensions of future-oriented repetitive thought: pessimistic repetitive future thinking, repetitive thinking about future goals, and positive indulging about the future. They also completed self-report measures of depressive symptoms and suicide ideation at baseline and 3-month follow-up. Pessimistic repetitive thinking had a significant direct effect on suicide ideation at 3 months (c' = 0.44, 95 % CI [0.01, 0.86]). Both pessimistic repetitive thinking (ab = 0.39, 95 % CI [0.09, 0.70]) and positive indulging (ab = 0.54, 95 % CI [0.03, 1.00]) showed a significant indirect effect on suicide ideation through increased depressive symptoms at 3 months. Repetitive thinking about future goals was not significantly associated with either depressive symptoms or suicide ideation at follow-up. These findings extend our understanding of the cognitive processes underlying suicide ideation among adolescents, highlighting pessimistic future thinking and positive indulging as a potential intervention target distinct from traditional constructs like rumination. Results suggest that how adolescents repetitively think about their futures, particularly their tendency to engage in pessimistic future-oriented repetitive thought, may be important in maintaining suicide ideation.