Background Depression-related negative emotional bias is widely regarded as a core cognitive mechanism underlying the maintenance of depressive states. However, it remains unclear whether such biases disrupt fundamental cognitive enhancement processes driven by transient arousal. The Attentional Boost Effect (ABE) reflects a transient, phasic arousal mechanism triggered by target detection and is thought to operate relatively independently of emotional valence. This study examined whether ABE remains intact in depression-prone individuals and how alerting cues and emotional valence modulate this effect.Method A 2 (Group: depression-prone vs. healthy control) × 2 (Alerting cue: Cue vs. No-Cue) × 3 (Emotional valence: positive vs. neutral vs. negative) × 2 (Stimulus type: target vs. distractor) mixed design was employed. Eighty-one university students completed a classic ABE paradigm.Result (1) Both depression-prone and control participants exhibited a robust ABE, suggesting that arousal-driven encoding enhancement mechanisms remain functionally preserved in subclinical depression; (2) During encoding, a positivity advantage emerged under the No-Cue condition, whereas alerting cues significantly improved detection efficiency and attenuated valence-related differences; (3) During recognition, alerting cues amplified the ABE magnitude for emotional stimuli, with a particularly pronounced enhancement for positive information.Conclusion Depressive negative bias did not impair the fundamental arousal-regulation pathway. Instead, cognitive processing in depression proneness showed contextual modulation. Exogenous alerting cues may function as compensatory signals, optimizing attention allocation and memory enhancement. These findings provide direct behavioral evidence distinguishing valence-driven and transient arousal-driven cognitive enhancement pathways and offer theoretical support for personalized intervention strategies based on arousal modulation.