Neuroendocrine aspects of attention deficit hyperactivity disorder.

This article summarizes the existing neuroendocrine literature and reports the growth hormone response to stimulation with L-dopa and clonidine in male children and adolescents with attention deficit hyperactivity disorder. Because growth hormone secretion is regulated by monoamine neurotransmitters, hyposecretion of growth hormone may reflect generalized changes in the neurochemical substrate of this disorder. With refinement, these neuroendocrine challenge tests may become unique biologic markers in identifying attention deficit hyperactivity disorder in children and adolescents.