Heightened suicidal risk in ADHD and subthreshold ADHD: Understanding the role of psychiatric comorbidities

Recently, adult ADHD diagnoses have increased, complicating treatment when comorbid with other disorders. Subthreshold ADHD(sADHD) also poses challenges, especially with comorbidities and suicidality. This study explores psychiatric comorbidities' role in ADHD and sADHD suicidality.

We analyzed microdata from the National Mental Health Survey of Korea 2021 to examine the association of ADHD on comorbidities and suicide-related behaviors.

Of the 5511 participants, 194(3.52 %) were diagnosed with ADHD, and 775(14.1 %) had sADHD. In 12-month prevalence, suicidal ideation and plans were more prevalent in both ADHD and sADHD patients than in controls, with higher odds ratios(ADHD vs. control OR 12.87; suicidal ideation, 54.06; suicidal plan, sADHD vs control OR 8.26; suicidal ideation, 17.63; suicidal plans). Lifetime suicidal ideation and plans were notably associated with alcohol use disorder(OR 6.15 in ideation, 3.83; plan) and nicotine use disorder in participants with ADHD(OR 5.36 in ideation, 5.31; plan), whereas sADHD associations were found with alcohol use disorder(OR 1.80 in ideation) and depressive disorder(OR 1.90 in ideation) compared to the controls. Additionally, differences in suicidal behavior between sADHD and ADHD were identified for alcohol use disorder(OR 3.42 in ideation, 4.15; plan) and nicotine use disorder(OR 4.02 in ideation, 4.98 in plan).

These results indicated a heightened risk of psychiatric comorbidities and suicidal ideation or plans in the ADHD and sADHD groups. These results suggest the need for a more diverse focus on comprehensive mental health assessments and proactive support for patients with ADHD, regardless of symptom severity.