Reduced threat-safety discrimination and generally enhanced generalization responses in adversity exposed youth with...

Fear learning and generalization is one of the postulated transdiagnostic processes linking childhood adversity to psychopathology. However, limited studies have investigated the processes in the context of childhood adversity, especially in youths with emerging psychiatric symptoms, although adolescence and young adulthood are critical periods when psychopathology most often emerges.

Twenty-six adversity-exposed youths (aged 17-24 years old) with (sub-)clinical psychiatric symptoms (scoring above the predefined cut-off of at least two symptom dimensions of depression, anxiety and psychosis) and 29 healthy controls (no history of adversity), underwent a fear learning and generalization paradigm. Fear responses were assessed using risk ratings and reaction times.

During fear acquisition, the adversity group showed reduced threat-safety discrimination (quantified as the difference score between the danger and the safety cue). Contrary to our hypothesis, this effect was driven by their enhanced risk ratings for the safety cue rather than blunted responses to the danger cue. Dimensional analysis further revealed that higher levels of childhood adversity were associated with relatively enhanced risk ratings for the safety cue as compared to the danger cue, an effect that persisted after controlling for current psychiatric symptoms (depression, anxiety and psychosis). During fear generalization, the generalization gradient in the adversity group did not differ from the control group. However, adversity-exposed youths reported generally enhanced risk ratings across stimuli, suggesting quantitatively altered responses (similar, but upward shifted gradient). While dimensional analysis linked the generally enhanced risk ratings to higher levels of childhood adversity, this association did not survive correction for psychiatric symptoms.

The observed enhanced responses for the safety cue during acquisition and the generally enhanced responses during generalization are similar as those observed in patients with a diagnosable psychiatric disorder in prior studies. This suggests that the observed pattern may reflect an adversity-related vulnerability for further progression to psychopathology in this population.