5 - (IOP 5) Moderating Role of Trauma Exposure on Unpredictable and Predictable Threat Startle Responses in Estimating Posttraumatic Stress, Anxiety, and Depression Symptoms in Youth

The impact of potentially traumatic events (PTEs) on youth’s mental health remains a critical area of research, including how individual differences, such as psychophysiological responses to threat, may influence symptom development. Trauma exposure is a known risk factor for psychopathology, and startle response – an indicator of threat processing – has been linked to childhood trauma (Sullivan et al., 2023) and anxiety in youth (Jovanovic et al., 2014). However, the interaction between threat-related startle and PTE exposure in predicting internalizing symptoms is not fully understood. Adult research shows varied startle response based on PTE exposure and symptom severity (McTeague et al., 2010) and differences based on threat predictability (Kreutzer & Gorka, 2021). This study aimed to explore these interactions and examine the role of threat predictability in youth.
The study included a diverse community sample of 230 youth aged 8-16 (M = 11.70, 52% female, 51% racial and/or ethnic minority). Startle responses were assessed during a No Threat, Predictable Threat, and Unpredictable Threat (NPU) task. Symptoms of posttraumatic stress disorder (PTSD), anxiety, and depression were self-reported via the UCLA PTSD Reaction Index, Multidimensional Anxiety Scale for Children (MASC), and Children’s Depression Inventory (CDI). Total PTE exposure was assessed via youth and caregiver interviews. Moderation analyses were conducted to test direct and indirect effects of startle and PTE exposure predicting symptoms, with age and gender as covariates (Hayes, 2013). Threat-related startle included Predictable > No Threat and Unpredictable > No Threat contrasts.
PTE exposure interacted with unpredictable threat responses to predict PTSD (F(5,69)=3.77, p=.005), anxiety (F(5,191)=4.04, p=.002), and depression (F(5,191)=7.88, p<.001) symptoms. Simple slopes revealed positive associations between unpredictable threat startle response and symptoms only at high levels of PTE exposure. At low and average levels, startle was unrelated to symptoms. For predictable threat responses, PTE exposure moderated the relationship with depression symptoms (F(5,190)=7.69, p<.001), while PTSD and anxiety models were nonsignificant. Simple slopes showed a positive association between predictable threat startle and depression symptoms only at high PTE exposure levels. Main effects of threat-related startle on symptoms were nonsignificant in all models.
Findings highlight the importance of considering PTE history in the association between threat-related startle and internalizing symptoms in youth. Psychophysiological startle, a key intervention target, was related to symptoms only in youth with high PTE exposure. Further, startle to predictable threat was uniquely linked to depression, while responses to unpredictable threat were associated across internalizing indices for youth with high PTE exposure. While requiring additional research, patterns of threat-related startle may indicate potential unique biomarkers of trauma-related impairment. The study’s diverse sample and multi-informant PTE assessment strengthen its findings, though it is limited by the cross-sectional nature of self-reported symptoms.