Risk of Suicidal Events in Youths Taking Atomoxetine Compared with Those on Methylphenidate; An Observational Cross-Sectional Study

Abstract

Background: Stimulants such as methylphenidate and atomoxetine, a nonstimulant norepinephrine reuptake inhibitor, are approved for the treatment of Attention Deficit Hyperactivity Disorder (ADHD). Associations between the use of methylphenidate or atomoxetine with suicidal ideation and suicide-related behavior have been reported in the literature. The present study aimed to compare the effects of atomoxetine with that of methylphenidate on suicidal ideation and behavior in children and adolescents. Methods: Children and adolescents between 7 to 17 years of age with the diagnosis of ADHD, based on DSM-5 criteria, were included in this observational, cross sectional study. The suicidal ideation was assessed among children and adolescents who have been receiving either atomoxetine or methylphenidate for at least 12 months prior to entering the study. A Farsi version of Positive and Negative Suicide Ideation (PANSI) inventory was applied for the assessment. Differences among age groups, duration of therapy and comparison of positive and negative scores in both genders were analyzed using t-test. In addition, a one-way analysis of variance (ANOVA) was applied to examine the differences in positive and negative scores among different age groups. Moreover, chi-square and Fisher’s exact tests were performed to examine the effects of past history of drugs and other present illnesses on suicidal ideation. P-value of <0.05 was considered as significant. Results: A total of 57 students between 7 to 17 years of age were enrolled in this study. Twenty-eight patients have been taking atomoxetine at doses of 10 to 60 mg/day while 29 were on methylphenidate 7.50-55 mg/day. The mean positive and negative scores in the atomoxetine group were found to significantly differ (P=0.001) from those in the methylphenidate group. No risk of suicidal ideation was detected in the atomoxetine group, while in the methylphenidate group 15 out of 29 patients (51.7%) scored above the cutoff point. In terms of the relationship between suicidal ideation and history of other drugs prior to the current therapy and other concurrent disorders, chi-square test showed no significant difference in methylphenidate group (P=0.100 and 0.500 respectively). This analysis was not considered in atomoxetine group due to the absence of suicidal ideation. Conclusion: The authors of this study suggest that atomoxetine may be a safer choice than methylphenidate for the treatment of ADHD when suicidal ideation is a concern. In this regard, monitoring suicidal ideation and behavior along with family education should be considered in all children and adolescents suffering ADHD.