Acetyl-L-Carnitine as an Adjunctive Therapy in the Treatment of Attention-Deficit/Hyperactivity Disorder in Children and Adolescents: A Placebo-Controlled Trial

Abstract

The objective of this study was to test whether a previous observed Acetyl-L-carnitine (ALC) treatment effect could be repeated in an ALC adjunctive therapy treatment trial of attention-deficit/hyperactivity disorder (ADHD) in children and adolescents. This was a six-week, randomized clinical trial undertaken in an outpatient child and adolescent clinic. Subjects included 40 outpatients (28 boys and 12 girls) between the ages of 7-13 who met the DSM-IV-TR diagnostic criteria for ADHD. All study subjects were randomly assigned to receive treatment using capsules of ALC doses ranging from 500 to 1,500 mg/day depending on the weight of the child plus methylphenidate at a dose of 20-30 mg/day depending on weight or Placebo plus methylphenidate at a dose of 20-30 mg/day depending on weight. The principal measure of outcome was the Teacher and Parent attention deficit/hyperactivity disorder Rating Scale- IV. No difference was observed between the two groups on the Parent and Teacher Rating Scale scores (df = 1; F = 0.10; P = 0.74 and df = 1; F = 0.22; P = 0.63 respectively). Side effects consisting of headache and irritability were observed more frequently in the methylphenidate plus placebo group. The results of this study do not support the application of ALC as an adjunctive therapy to methylphenidate in children and adolescents with ADHD.

Use of Non-Pharmacological Supplementations in Children and Adolescents with Attention Deficit/Hyperactivity Disorder: A Critical Review

“…Regarding these studies results, ALC alone did not improve ADHD symptoms [15], but it reduced adverse effects when taken in addition to MPH. Moreover, l-carnosine seemed to improve behavioral problems according to parents [17].…”

Attention deficit/hyperactivity disorder as an associated feature in OCTN2 deficiency with novel deletion (p.T440‐Y449)

“…In one previous randomized, double‐blind, placebo‐controlled double‐crossover trial of the efficacy of carnitine in the treatment of boys with attention deficit/hyperactivity disorder, the investigators found a significant decrease in attention problems and aggressive behavior in 13/24 boys with ADHD with a decrease of 20–65% (8–48 points) in responsive boys as assessed by the Child Behavior Checklist (CBCL) total problem rating scale . In a placebo‐controlled trial, the use of acetyl‐L‐carnitine as an adjunctive therapy to methylphenidate in the treatment of ADHD in children and adolescents showed no differences with the placebo plus methylphenidate group . In another multi‐site, placebo‐controlled trial of acetyl‐L‐carnitine in 112 children with ADHD, the primary intent‐to‐treat analysis of 9 DSM‐IV teacher‐rated inattentive symptoms was not significant; however, secondary analyses revealed a significant moderation by subtype with superiority of acetyl‐L‐carnitine over placebo in the inattentive type, with an opposite tendency in combined type .…”

Dietary and Nutritional Treatments for Attention-Deficit/Hyperactivity Disorder: Current Research Support and Recommendations for Practitioners

“…However, children with ADHD-inattentive type improved significantly more on carnitine than placebo, a finding not present in ADHDcombined type. In a recent trial, L-carnitine was not effective as a complementary treatment to stimulant medication for children with ADHD [30]. Although results have not documented consistent effects on hyperactivity/ impulsivity, the attention effects, in light of the known favorable effects on cardiovascular health [31], make this a reasonable treatment to consider for those unresponsive to or unwilling to accept conventional treatment for inattentivetype ADHD.…”