Circulatory levels of catecholamines, serotonin and lipids in attention deficit hyperactivity diiorder

Abstract

Attention deficit hyperactivity disorder (ADHD) may be associated with a dysregulation of the catecholaminergic and serotonergic systems. Furthermore, ADHD is frequently complicated by aggressive impulsive behaviour, which is suggested to be related to low serum cholesterol levels. We examined the relationship between blood serotonin, norepinephrine, dopa and lipid levels and the degree of hyperactivity, impulsiveness, lack of concentration, and aggressiveness in boys with ADHD of low and high severity as determined by a specially designed formulated scale based on the DSM-IV criteria for ADHD. No differences were noted between the groups in any of the peripheral biological parameters except blood serotonin, for which a tendency (P=0.08) towards lower levels was observed in the children with more severe disorder. We conclude that children with severe ADHD may have a different serotonin turnover compared to children with mild ADHD. These results may have implications for our understanding of the pathogenesis of ADHD, at least the more severe type.

Exploration of 19 serotoninergic candidate genes in adults and children with attention-deficit/hyperactivity disorder identifies association for 5HT2A, DDC and MAOB

“…17,18 Altered cerebrospinal fluid concentrations of 5-hydroxyindoleacetic acid, a serotoninergic metabolite, are consistently associated with hyperactivity, aggression and impulsive behavior, common characteristics in ADHD. [19][20][21] In addition, it has been reported that tryptophan depletion, the essential amino acid for brain serotonin synthesis, impairs learning and memory in healthy controls. 22 Pharmacological studies have also provided insight into the role of serotonin in ADHD susceptibility.…”

Evidence for the serotonin HTR2A receptor gene as a susceptibility factor in attention deficit hyperactivity disorder (ADHD)

“…5,6 These results have been further supported by a recent study that also found a tendency towards low platelet serotonin in a sample of children with severe ADHD. 7 Additional support for a serotonin hypothesis is demonstrated by the moderate efficacy of several serotonin enhancing agents in the treatment of ADHD including selective serotonin reuptake inhibitors (SSRIs) 8 and certain selective monoamine oxidase inhibitors. 9 Several lines of evidence have indicated abnormal serotonergic function in children with disruptive behaviour disorders (ADHD, ODD, CD) who display marked problems with hyperactivity, impulsivity, and aggression.…”

Animal models of attention deficit/hyperactivity disorder (ADHD): a critical review

“…The serotonin transporter gene has been proposed as a candidate gene for ADHD and may be involved in the aetiology of impulsivity (Halperin et al 1997;Spivak et al 1999;Stein et al 1993). One of the most studied polymorphisms of this gene (the 5HTTLPR) is located in the promoter region of this gene.…”