Executive function moderates the relationships between acoustic startle and symptoms of PTSD and depression: A 6-month longitudinal study of young adults.

OBJECTIVE

To examine the 6-month longitudinal relationships among startle response, executive function (EF), and symptoms of PTSD and depression in young adults.

METHODS

A total of 88 trauma-exposed (TE: 78.4 % male; 19.07 ± 1.04 years) and 38 healthy control (HC: 73.7 % male; 19.45 ± 0.92 years) participants were assessed twice over a six-month interval. EFs including executive inhibition, semantic inhibition, executive processing, and online updating were measured using a battery of neuropsychological tasks. Startle and habituation were assessed using a 95 dB stimulus, with prepulse inhibition (PPI) measured at 60 ms (PPI60) and 120 ms (PPI120) lead intervals using a 75 dB prepulse.

RESULTS

No significant group differences were observed in EF, startle response, habituation, or PPI60. However, the TE group showed higher levels of PTSD and depression and lower PPI120 (partial η2 from 0.03 to 0.08). Partial correlation analyses indicated high stability of EF and startle response in both groups (r from 0.45 to 0.83), whereas habituation and PPIs exhibited weak stability. Weak correlations were found among EFs, startle indicators, and clinical symptoms. Generalized estimating equation models revealed that poorer executive inhibition was positively associated with PTSD and depression in the TE group. Additionally, significant interactions between semantic inhibition and startle response were observed for both PTSD and depression. Among individuals with poorer semantic inhibition, higher startle response was associated with increased clinical symptoms.

CONCLUSIONS

Both startle reactivity and EFs represent vulnerability factors for post-traumatic psychopathology and may exert combined effects on clinical symptoms in high-risk populations.