RESUMEN
BACKGROUND: Cognitive inflexibility has recently been investigated as potential vulnerability factor for suicidal ideation (SI), but the context in which it may convey risk is unclear. Life stress has also been reliably associated with SI among adolescents, and following a stress-diathesis model, may be a factor that moderates the relationship between cognitive inflexibility and SI. METHODS: Psychiatrically hospitalized adolescents (N = 259) at high risk for future SI were followed for 18 months after discharge. Interviews assessing life stress and SI and a neurocognitive task assessing cognitive inflexibility were conducted at six- and 12-months. SI was also assessed at 18-month post-discharge. Linear mixed models were used to determine the moderating effect of stress on the relationship between cognitive inflexibility and SI, accounting for relevant clinical and demographic covariates. RESULTS: Chronic stress moderated the association between cognitive inflexibility and SI, with a stronger association found among youth with greater levels compared to lower levels of chronic stress. This finding was maintained after statistically adjusting for depressive symptoms and relevant demographic covariates. No prospective associations between cognitive inflexibility, life stress, and SI were found. LIMITATIONS: SI was measured at 6-month intervals, precluding evaluation of the relationship on a more proximal timescale. CONCLUSIONS: Cognitively inflexible adolescents under conditions of high chronic stress are more likely to experience increased SI severity, supporting a cognitive inflexibility stress-diathesis model of SI in adolescents. The findings highlight the importance of assessing these modifiable factors among adolescents at a high risk for SI.