PhD Candidate Groningen Research Institute of Pharmacy, Unit of PharmacoTherapy, ‐Epidemiology and ‐Economics, University of Groningen, Groningen, The Netherlands Hong Kong SAR, Hong Kong
Background: There have been rising concerns regarding the risk of suicide attempt upon use of attention-deficit/ hyperactivity disorder (ADHD) pharmacological treatments.
Objectives: To examine the risk of suicide attempt among individuals treated with ADHD medication across five countries/region.
Methods: This multinational self-controlled case series study examined the risk of suicide attempt among individuals treated with ADHD medication using electronic health records from population-based databases across Hong Kong, New Zealand, South Korea, Taiwan, and the United Kingdom. We included individuals who initiated ADHD medication and had a recorded suicide attempt during the study period (2001-2020). We calculated incidence rates for suicide attempt events in each predetermined exposure risk periods. Incidence rate ratios (IRR) in periods of exposure to ADHD medication compared with unexposed periods were calculated with conditional Poisson regression. The IRRs and their 95% confidence intervals (CIs) were estimated for each exposure risk periods.
Results: We identified 452, 4841, 313, 222, and 1058 patients from Hong Kong, New Zealand, South Korea, Taiwan, and the United Kingdom, respectively. Risk of suicide attempt was the highest during the pre-exposure period in all populations: Hong Kong, 90-days-pre-exposure (IRR 4.10, 95%CI 2.61-6.46), first-90-days-exposure (3.21, 1.95-5.28), post-90-days-exposure (1.24, 0.93-1.67); New Zealand, 90-days-pre-exposure (2.40, 2.10-2.75), first-90-days-exposure (1.54,1.28-1.85), post-90-days-exposure (1.06, 0.94-1.19); South Korea, 90-days-pre-exposure (2.67, 1.61-4.44), first-90-days-exposure (1.35, 0.70-2.62), post-90-days-exposure (2.22, 1.30-3.79); Taiwan, 90-days-pre-exposure (2.66,1.49-4.74), first-90-days-exposure (no events were observed), post-90-days-exposure (0.87,0.46-1.66); and United Kingdom, 90-days-pre-exposure (2.07, 1.41-3.03), first-90-days-exposure (1.47, 0.80-2.69), post-90-days-exposure (1.45, 1.08-1.94).
Conclusions: Although initiation of ADHD medication was associated with suicide attempt, the risk was the highest in the period immediately before ADHD medication initiation. Thus, the results of this multinational study do not support a causal association between ADHD medication use and suicide attempt.
