Stress Sensitivity and Emotion Regulation Difficulties as Mediators between Adverse Childhood Experiences and Suicidal Ideation - An Ecological Momentary Assessment Study

Background: Adverse childhood experiences (ACEs) are well-established risk factors for suicidal ideation onset. We investigated whether ACEs influence the short-term temporal dynamics of ideation in adulthood, and the potential role of stress sensitivity and difficulties in emotion regulation (DER) in this association.Methods: A total of 352 university students (79.8% females; mean age = 20.6, SD= 2.01) reporting passive suicidal ideation at least once during a 14-day ecological momentary assessment (EMA) were included in the study. At baseline, participants reported frequency of six ACE types (household dysfunction, physical, emotional, and sexual abuse, neglect and bullying) and DER. Daily assessments of passive ideation were used to calculate five individual-level indicators capturing intensity (mean and maximum ideation), frequency (percentage of days with ideation), and variability (SD and root mean square of successive differences). Stress sensitivity was calculated from momentary EMA assessments. Structural equation models examined associations between ACE frequency and ideation indicators, evaluating mediating roles of DER and stress sensitivity.Results: Frequency of all ACE types was associated with ideation intensity, frequency and variability, with median total effect estimates of β= 0.31 (IQR= 0.30-0.33), β= 0.27 (IQR= 0.25-0.28), β= 0.24 (IQR= 0.22-0.27), respectively. These associations were partially mediated by stress sensitivity and DER, with mediation proportion estimated at 17.4% (IQR= 16.3-19.1) and 25.5% (IQR= 23.3-28.1), respectively.Conclusions: Among young adults with suicidal ideation, ACE frequency is moderately and non-specifically associated with ideation intensity, frequency, and variability. Findings suggest stress sensitivity and DER could play a role in explaining this association.Open Science: Preregistration, codes, anonymized data, and results are available at osf.io/6yah5.4Keywords: Suicidal Ideation; College Students; Experience Sampling Methods; Mental Health; Affect Reactivity; Emotion Regulation.