Failure to differentiate between threat-related and positive emotion cues in healthy adults with childhood interpersonal or adult trauma.

Enhanced threat-related processing is associated with both elevated anxiety and childhood exposure to trauma. Given the paucity of evidence regarding the effects of childhood and adult trauma exposure on subsequent psychophysiological processes in the absence of psychopathology, we investigated the relative impacts of childhood interpersonal and non-interpersonal trauma, as well as adult trauma exposure on neural processing of threat in healthy adults. We measured peak amplitudes of the N170 face-sensitive visual ERP component response to non-conscious and conscious Angry (threat) versus Happy (non-threat, positive) and Neutral (non-threat baseline) faces at temporo-occipital sites (right-T6; left-T5) in 489 psychiatrically asymptomatic adults (aged 18-70 years, 54% women, 94% right-handed). N170 peak amplitude differences between Angry vs Happy or Neutral faces were calculated and subjected to hierarchical multiple regression analysis, with trauma types (childhood interpersonal, childhood non-interpersonal and adult trauma) entered as predictors of interest. After controlling for sociodemographic and health factors, N170 peak amplitudes for non-conscious Angry vs Happy faces were inversely associated with childhood interpersonal trauma at T6 and adult trauma exposure at T5. Post-hoc repeated measures ANOVA indicated that unlike adults without trauma exposure, trauma-exposed adults failed to show significantly reduced N170 responses to Happy relative to Angry faces during non-conscious processing. This suggests that childhood interpersonal and adult trauma exposure are associated with a failure to differentiate between non-threat or positive and threat-related emotion cues. This is consistent with generalised hypervigilance seen in PTSD, and suggests trauma exposure is associated with a generalized heightened responsivity to non-conscious non-threat or positive as well as threat-related emotion cues in psychiatrically healthy adults.