title: Problems of diagnosis and the definition of comparable groups: a neglected issue in drug research with children.
mesh_terms: D000367:Age Factors; D001925:Brain Damage, Chronic / Q000175:diagnosis / Q000188:drug therapy; D002648:Child; D002653:Child Behavior Disorders / Q000175:diagnosis* / Q000188:drug therapy*; D002665:Child Psychiatry / Q000592:standards*; D002986:Clinical Trials as Topic; D006801:Humans; D006948:Hyperkinesis / Q000175:diagnosis / Q000188:drug therapy; D007360:Intelligence; D008722:Methods; D011600:Psychopharmacology / Q000592:standards*; D012737:Sex Factors