Acute exercise for emotional pattern separation in youth with psychiatric symptoms and childhood adversity: a randomized controlled trial

Adolescence and young adulthood are critical periods for the emergence of transdiagnostic psychiatric symptoms. Pattern separation (PS) is the ability to discriminate between similar stimuli. Its behavioral proxy is mnemonic discrimination. PS is an important hippocampal function impaired in several mental disorders. Previous research demonstrated that while childhood adversity might lead to impaired PS, acute exercise could enhance it. Using a randomized controlled design, we examined the effect of acute moderate-intensity exercise on PS versus a rest condition in a group of young people. Building on our prior report in a healthy youth sample (Jennen et al., 2025), the present study examines adolescents and young adults with transdiagnostic psychiatric symptoms and childhood adversity, compared to healthy controls. We integrated behavioral and neural PS with an emotional mnemonic discrimination task and functional magnetic resonance imaging. Our analyses did not reveal significant effects of exercise or psychiatric symptoms on mnemonic discrimination and PS. Additionally, PS was not associated with symptom dimensions or childhood adversity. Across groups, we observed decreased discrimination for positive images and increased neural activation in the left centromedial amygdala for emotional images. No correlation between neural activity and mnemonic discrimination could be observed and exploratory analyses revealed no neural activity consistent with PS. We conclude that in our study neither mnemonic discrimination nor PS was associated with psychiatric symptoms or childhood adversity in adolescents and young adults with transdiagnostic psychiatric symptoms. In addition, acute exercise had no effect. Future research should prioritize establishing robust and reliable associations of both acute exercise and psychiatric symptoms with mnemonic discrimination and neural PS.