Attention-deficit/Hyperactivity Disorder Traits, Oppositional Defiance, Posttraumatic Stress Disorder Symptoms, and Suicidal Ideation under Family Support Influence

Attention-deficit/Hyperactivity Disorder Traits, Oppositional Defiance, Posttraumatic Stress Disorder Symptoms, and Suicidal Ideation under Family Support Influence

Background: Posttraumatic stress disorder (PTSD) is a prevalent mental health condition among military personnel, associated with elevated risks of anxiety, depression, and suicidal ideation (SI). Emerging evidence highlights overlaps between PTSD and childhood neurodevelopmental traits, such as attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder traits. While family support is protective, the specific moderated mediation pathways connecting early traits, PTSD symptoms, and SI remain underexplored. In this study, we intended to investigate these moderated mediation pathways, hypothesizing that family support buffers the indirect effects of childhood traits on suicidality via PTSD symptoms. Methods: In this cross-sectional study, from August 2024 to August 2025, we recruited 1,045 active-duty soldiers from northern Taiwan. We assessed PTSD symptoms (Davidson Trauma Scale), anxiety (Beck’s Anxiety Inventory-II), depression (Beck Depression Inventory, the second edition), SI (five-item Brief Symptom Rating Scale), retrospective childhood traits (Swanson, Nolan, and Pelham, Version IV Scale-Chinese version), and family support (Adaptation, Partnership, Growth, Affection, and Resolve Scale). Moderated mediation models examined pathways from childhood traits to SI. Results: Among 1,045 participants, probable PTSD prevalence was 3.6% (n = 38). These participants were younger, more likely female, and reported significantly lower family support (p < 0.001). Childhood ADHD and oppositional traits positively predicted SI both directly and indirectly through PTSD re-experiencing and arousal symptoms (p < 0.001). Family support showed a buffering moderating effect (mostly negative coefficients), but the results were not statistically significant. Conclusion: This study elucidates moderated mediation pathways linking childhood ADHD/oppositional traits to SI via PTSD symptoms, with family support offering protective buffering although nonsignificant. Our findings reveal gender disparities in Taiwanese military. Lower family support in PTSD groups highlights its resilient role, suggesting that interventions enhancing support could mitigate risks.