title: Developmental timing of exposure to elevated levels of phenylalanine is associated with ADHD symptom expression.
abstract: This study addresses attention deficit hyperactivity disorder (ADHD), with a focus on how the timing of a known biological insult affects ADHD symptom expression. The sample consists of children exposed to elevated levels of phenylalanine, either postnatally as in Phenylketonuria (PKU; n = 46) or prenatally as in Maternal PKU (MPKU; n = 15). Non-hyperphenylalaninemic siblings of children with PKU (n = 18) serve as controls. Results indicate that elevated levels of phenylalanine are associated with ADHD symptoms. The manifestations of the symptom expression are dependent on exposure timing: prenatal exposure is associated with a higher likelihood of expressing hyperactive/impulsive symptoms and postnatal exposure is associated with a higher likelihood of expressing inattentive symptoms. This toxicity is dose-dependent and higher levels of phenylalanine appear more detrimental.
authors.affiliation: Children's Hospital-Boston, Division of Psychology, Department of Psychiatry, Harvard Medical School, Longwood Avenue, Boston, Massachusetts, USA. antshelk@upstate.edu
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Antshel
authors.forename: Susan E
authors.initials: SE
authors.lastname: Waisbren
mesh_terms: D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000097:blood* / Q000453:epidemiology*; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009035:Mothers / Q000706:statistics & numerical data*; D010649:Phenylalanine / Q000097:blood*; D010661:Phenylketonurias / Q000097:blood* / Q000453:epidemiology*; D011247:Pregnancy; D011446:Prospective Studies; D013997:Time Factors
chemical_list: D010649:Phenylalanine