Stimulant Treatment Effect on Anxiety Domains in Children with Attention-Deficit/Hyperactivity Disorder with and without Anxiety Disorders: A 12-Week Open-Label Prospective Study

Objectives: The effect of stimulants on anxiety domains has not been systematically studied. We assessed prospectively the impact of stimulant treatment in children with attention-deficit/hyperactivity disorder (ADHD) on the severity of anxiety domains and on ADHD with comorbid anxiety disorders. Methods: Children with ADHD (n = 57, aged 6-15 years) started a stimulant or were switched from one stimulant to another. Assessments were conducted at four time points (baseline and weeks 2, 6, and 12) and consisted of parental questionnaires (ADHD rating scale, screen for child anxiety related disorders [SCARED]), and side effect questionnaire completed by a child psychiatrist. Results: A significant improvement in total SCARED scores was obtained after 12 weeks stimulant treatment in children both with and without anxiety disorders. Significant reductions were detected in generalized anxiety, separation anxiety, and school avoidance SCARED subscales, but not in panic and social anxiety subscales. ADHD symptoms significantly improved both in children with and without anxiety comorbidities. Conclusion: We found specific effects of stimulants on anxiety domains. Stimulant treatment, even for ADHD children diagnosed with comorbid anxiety disorders, is relatively safe regarding the risk of anxiety exacerbation. Moreover, the presence of anxiety symptoms or disorders does not interfere with the beneficial effect of the stimulants on the ADHD core symptoms. Clinical trial regestration number: IRB SMC-6893-20.