Attention deficit disorders: a study of peptide-containing urinary complexes.

In several behavioral disorders, we have observed that abnormal amounts of peptides and protein-associated peptide complexes are excreted in the urine. The gel filtration patterns of these excreted substances have some specificity for the different disorders. The urinary excretion of peptide-containing complexes was studied in 91 boys and 13 girls (mean age 9.4 years, range 1-23) with the clinical diagnosis of attention deficit disorder (ADD), with or without hyperactivity. The gel filtration of urine precipitate showed patterns in all patients that were different from those seen in 36 normal controls. Sixty-four patients had increased benzoic acid-glycoprotein-peptide complexes in the late peaks. The symptoms of all these patients fit the criteria for diagnosis of attention deficit disorder with hyperactivity (ADDH). Thirty-five patients showed reduced amounts of uric acid complexes in the late peaks. Clinically, this group, with the exception of three patients, fit the criteria for diagnosis of attention deficit disorder without hyperactivity. Five patients showed reduced amounts of all urinary complexes; four of these were hyperactive. Moderate exercise in control children did not change the urinary pattern. One urinary peptide fraction from hyperactive patients, purified to homogeneity, increased the uptake of 14C[5-HT] in platelets. Strict clinical, neuropsychological, and psychophysiological selection of the patients reduced the heterogeneity of the patterns. Although more studies are needed, the findings seem promising for the possibility of developing biochemical tests that may be helpful diagnostically.