Platelet serotonin transporter and 5-HT_2A receptor binding in adolescents with eating disorders

Abstract

The pathogenetic involvement of the serotonergic system in eating disorders is an established finding. Conclusions from platelet studies are based on results from investigations of subjects with a mean age of 20 years or more. The aim was to investigate whether previous findings in adults are valid also for adolescents who are examined within a relatively short interval after the onset of the eating disorder. [³H]paroxetine binding to the platelet serotonin transporter and [³H]lysergic acid diethylamide ([³H]LSD) binding to the 5-HT_2A receptor was studied in 15 female adolescents with eating disorders (11 with anorexia nervosa and 4 with clearly anorectic eating behaviour not fulfilling the criteria for anorexia nervosa) and 32 controls. The patients revealed a higher density of serotonin transporters and a lower density of 5-HT_2A receptors compared with healthy controls of the same age (775 ± 165 vs. 614 ± 111 fmol/mg protein (p = 0.003) for [³H]paroxetine binding and 215 ± 59 vs. 314 ± 151 fmol/mg protein (p = 0.005) for [³H]LSD binding). The findings of increased density of platelet serotonin transporters and reduced density of 5-HT_2A receptors differ from previous results in older patients. The lower patient age and the short duration of disease in the present study, possibly in conjunction with variations in stress-related psychological and biological factors, may have caused these differences. Although the present findings contradict prevailing evidence, they add further information concerning the nature of serotonergic involvement in eating disorders and indicate that demographic and course-related factors might influence the regulation of the serotonin system in these disorders.

KEYWORDS: :

• eating disorders
• anorexia nervosa
• serotonin
• platelets
• [³H]paroxetine binding
• [³H]LSD binding