REVIEW OF: Gamal F et al, CNS Neurol Disord Drug Targets 2022;21(8):717–723

STUDY TYPE: Randomized, double-blind, placebo-controlled trial

Many supplements have been touted to help ADHD. The pathophysiology of this disorder may be associated with oxidative stress, so it is reasonable to consider an antioxidant intervention (Joseph N et al, J Atten Disord 2013;19(11):915–924). In this study, researchers tested whether augmentation of atomoxetine with the antioxidant coenzyme Q10 would further improve ADHD symptoms.

Researchers recruited 60 children ages 6–16 years who continued to have ADHD symptoms despite taking atomoxetine for six months. Half received placebo and the other half received coenzyme Q10 (1–3 mg/kg/day). Serum levels were not checked in this study; however, the dosage range came from a pediatric migraine study that showed increased coenzyme Q10 serum levels from a mean of 0.6 μg/mL to 1.2 μg/mL (Hershey AD et al, Headache 2007;47(1):73–80). ADHD symptoms were measured with the Conners Parent Rating Scale-48 before and after one, three, and six months of treatment. There was no industry funding for this study.

The addition of coenzyme Q10 yielded a 16% greater improvement than placebo in ADHD hyperactivity, impulsivity, and learning problems after six months of treatment. Adverse effects included nausea; however, there was no statistically significant difference in adverse effects between the groups.

Since this study was conducted in Egypt, where stimulants are not widely available, the patient population may be different than in the US, where many people are prescribed atomoxetine if they are unable to tolerate stimulants.

Carlat Take

There is not yet enough evidence to recommend coenzyme Q10 as a standard treatment for ADHD. However, many patients with ADHD do not tolerate stimulant medication or get only partial benefit from atomoxetine or alpha-agonists. For children who continue to struggle with hyperactivity, impulsivity, and learning despite optimizing existing treatments, we can add coenzyme Q10 to our list of understudied, probably harmless, and possibly helpful adjunctive supplements to try.