Medication for Attention-Deficit/Hyperactivity Disorder and Suicidal Behavior: A Register Based Study

Monday, 18 August 2014: 11:45 AM
Boardroom (Dena'ina Center)
Qi Chen, MD , Karolinska Institute, Stockholm, Sweden
Arvid Sjölander, PhD , Karolinska Institute, Stockholm, Sweden
Bo Runeson, PhD , Karolinkska Institute, Stockholm, Sweden
Brian M. D'Onofrio, PhD , Indiana University, Bloomington, IN
Paul Lichtenstein, PhD , Karolinska Institute, Stockholm, Sweden
Henrik Larsson, PhD , Karolinska Institute, Stockholm, Sweden
INTRODUCTION: Stimulant and non-stimulant medications have been increasingly used in the United States and Europe for the treatment of Attention Deficit/Hyperactivity Disorder (ADHD), but the drug safety concerning suicidal behavior remains unclear. In this study, we aimed to investigate the association between ADHD medication and risk of concomitant suicidal behavior among patients with ADHD.

METHODS: We used data obtained from Swedish national registers to identify a cohort of individuals born between 1960 and 1996 with a clinical diagnosis of ADHD (N=37,936 patients). Patients were followed for 4 years (2006-2009) for their medication treatment status and suicide-related events consisting of suicide attempt and completed suicide. Cox and stratified Cox regression models were used to compare the incidence rates of suicide-related events during treatment periods and non-treatment periods at the population level (between patients) and within patients.

RESULTS: Among 37 936 patients with ADHD, 7019 suicide-related events occurred during 150 721 person years of follow-up. At the population level, the use of ADHD medication was associated with an increased rate of suicide-related events (hazard ratio 1.31, 95% confidence interval 1.19 to 1.44). However, the within-patient comparisons showed a reversed association between the use of ADHD medication and rate of suicide-related events (0.89, 0.79 to 1.00). Among stimulant users, we observed a reduced within-patient rate of suicide-related events during treatment periods (0.81, 0.70-0.94). Among non-stimulant/mixed users, we observed no significantly increased within-patient rate of suicide-related events during non-stimulant treatment periods (0.97, 0.72 to 1.31).

CONCLUSIONS: We found no evidence for a positive association between the use of ADHD medication and the risk of concomitant suicidal behavior among patients with ADHD. A slightly protective effect of stimulants on concomitant suicidal behavior was observed. The study highlights the importance of using quasi-experimental approaches to address selection effects in future pharmaco-epidemiological studies.