Symptoms of attention-deficit/hyperactivity disorder (ADHD) and suicidality in children appear to be mediated by depression, irritability, and anxiety, according to study results published in the Journal of Affective Disorders. Two-thirds of children with ADHD have one or more comorbid psychiatric symptoms, and depression in particular can be a major risk factor for suicidality in youth.
Tomer Levy, MD, and colleagues measured symptoms of ADHD, depression, irritability, anxiety, and suicidality in 1516 patients (age range, 6 to 17 years; 74% boys; 61.1% diagnosed with ADHD) at an outpatient ADHD clinic at a children’s hospital in Toronto, Ontario, Canada. They excluded children diagnosed with intellectual disability, psychosis, bipolar disorder, or autism. The researchers used teacher and parent questionnaires to assess symptoms, and they constructed separate multiple mediator models.
Suicidality was linked to symptoms of ADHD, such as inattention, hyperactivity, and impulsivity, in both parent (odds ratio [OR], 1.10; 95% CI, 1.07-1.14; P =.001) and teacher (OR, 1.08; 95% CI, 1.03-1.15; P =.002) reports. Psychosocial adversity, an amalgamation of risk factors including financial problems and domestic violence, was significantly associated with suicidality as reported by parents (OR, 1.61; 95% CI, 1.37-1.90; P <.001) and teachers (OR, 1.33; 95% CI, 1.00-1.76; P <.001).
Depression mediated the association between ADHD and suicidality at 39.1% and 45.3% of total effect for parent (OR, 1.19; 95% CI, 1.11-1.30; P =.001) and teacher (OR, 1.31; 95% CI, 1.17-1.48; P =.001) reports, while irritability accounted for 36.8% (OR, 1.17; 95% CI, 1.08-1.28; P =.001) and 38.4% (OR, 1.18; 95% CI, 1.05-1.35; P =.001) of the effect, respectively. Anxiety symptoms mediated 19% of the total effect between ADHD and suicidality for parent (OR, 1.11; 95% CI, 1.04-1.19; P =.003) but not teacher reports. After controlling for depression, irritability, and anxiety, the investigators found no direct effect of ADHD symptoms on suicidality, suggesting that the “relationship was indirect and a function of these common comorbidities.”
Evidence from other studies has suggested that irritability may be a risk factor for suicidality, but the investigators contend that “to our best knowledge, our study is the first to suggest that the association between irritability symptoms and suicidality is already evident in such a young age group.” The researchers admit, however, that their results indicating a mediating role for depression, anxiety, and irritability “cannot be taken as evidence that these are causal mediators of the ADHD-suicidality effect.” They added that a symptom such as irritability may be a marker for aggression, which was not measured in this study.
The investigators advised that practitioners consider comorbid traits when estimating and managing the risk of suicidality in children with ADHD.
Levy T, Kronenberg S, Crosbie J, Schachar RJ. Attention-deficit/hyperactivity disorder (ADHD) symptoms and suicidality in children: the mediating role of depression, irritability and anxiety symptoms. J Affect Disord. 2020. doi:org/10.1016/j.jad.2020.01.022