Associative Learning Difficulties following Childhood Trauma Exposure: A Transdiagnostic Risk Factor for Psychopathology

Abstract

Childhood trauma is associated with greater transdiagnostic risk for psychopathology. Smaller hippocampal volume is associated with both childhood trauma and multiples forms of psychopathology. We propose that childhood trauma may lead to impairments in associative learning, a basic function of the hippocampus, which in turn may increase general vulnerability for psychopathology. Children (n=84, 9-19 years, 55 exposed to trauma involving interpersonal violence) completed four behavioral tasks assessing associative learning of visual, auditory, contextual, and temporal information. The tasks involved facial stimuli with neutral, happy, and angry expressions, with the exception of temporal encoding. Participants also completed a structural MRI scan. A latent factor for general psychopathology (“p-factor”)—representing co-occurrence of psychopathology symptoms across multiple internalizing and externalizing domains—was estimated using confirmatory factor analysis. Childhood trauma exposure was associated with worse associative memory, and smaller hippocampal volume mediated this association. Difficulties with associative learning were observed in trauma-exposed children across different information types and irrespective of the emotional nature of the stimuli, suggesting that poor associative learning is not specific to threat-related cues. Associative memory improved with age for participants without trauma exposure, but not for participants exposed to trauma. Finally, lower associative learning performance was associated with higher scores on the general psychopathology factor and mediated the association of trauma with the p-factor. Broad hippocampus-dependent associative learning difficulties may be one transdiagnostic mechanism linking childhood trauma to psychopathology.