Effect of probiotics as an adjunctive therapy with Ritalin among ADHD children and adolescents: a triple-blind randomized controlled trial

Objective Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common mental disorders in children. Evidence regarding the impact of probiotics supplementation in ADHD children is limited and controversial. Thus, this study aimed to assess the effect of probiotics as an adjunctive therapy with Ritalin among ADHD children and adolescents.Methods This study was a triple-blind, randomized controlled trial of 60 Iranian ADHD patients aged four to sixteen. The participants were randomly assigned to receive probiotics supplements containing both Lactobacillus plantarum PTCC 1896™ (A7) and Bifidobacterium animalis subsp. Lactis (BB-12®) (n = 30) or placebo (n = 30) for 8 weeks. ADHD symptoms were assessed using Conners’ Parent Rating Scale (CPRS) and Integrated Visual and Auditory Continuous Performance Test (IVA/CPT) at baseline and during the study.Results This study showed a significant decrease in the CPRS total score after 4 weeks of intervention in the probiotic group (baseline: 43.96 ± 21.52; fourth week: 37.22 ± 23.01; p = 0.01). However, no significant finding was found for the total score of the CPRS after 8 weeks. Moreover, at the end of the study, a significant increase was observed in score of auditory response control in the probiotic versus the placebo group (probiotic: 91.55 ± 16.69; placebo: 80.55 ± 17.43; p = 0.02).Conclusions Probiotics supplementation with Ritalin may have some beneficial effects among ADHD children and adolescents, such as improving auditory response control and total score of CPRS. However, further clinical trials are required to clarify the impact of probiotics on ADHD.