Attention-deficit/hyperactivity disorder (ADHD) symptoms and suicidality in children: The mediating role of depression, irritability and anxiety symptoms

Background: Attention-deficit/hyperactivity disorder (ADHD) is associated with increased suicidality risk. Yet, potential mechanisms transmitting the effect of ADHD to suicidality remain unclear. We investigated whether depression, irritability and anxiety symptoms mediate between ADHD symptoms and suicidality. Methods: ADHD, depression, irritability and anxiety symptoms as well as suicidality (composited of suicidal ideation, attempts or self-harm) were measured in an outpatient clinic for ADHD (N = 1,516, 6-17 years old, 61.1% diagnosed with ADHD) using parent and teacher questionnaires. Multiple mediator models adjusted for age, sex and psychosocial adversities were constructed separately for parent- and teacher-report. Results: Parents reported higher rates of suicidality than did teachers (12.1% and 3.8%, p < .001). Suicidality was associated with parent (OR = 1.10, 95%CI: 1.07-1.14) and teacher (OR = 1.08, 95%CI: 1.03-1.15) reported ADHD symptoms. The association between ADHD symptoms and suicidality was mediated by both parent- and teacher-reported depression (39.1% and 45.3% of total effect, respectively) and irritability symptoms (36.8% and 38.4% of total effect, respectively). Anxiety symptoms mediated between ADHD and suicidality for parent- but not teacher-report (19.0% of total effect). No direct effect of ADHD symptoms was found once depression, irritability and anxiety were controlled. Limitations: The cross-sectional design limits the ability to determine causal order between mediators and outcome. Conclusions: Our results confirmed the association between ADHD symptoms and suicidality. However, this association was indirect and fully mediated by symptoms of depression, irritability and anxiety. Assessing these symptoms may enable an estimate of suicidality and help managing suicidal risk in ADHD.