The clinical characteristics and treatment methods used for children with ADHD were examined by questionnaires sent to 81 practicing psychiatrists and analyzed at the American Psychiatric Association, Washington, DC. The majority of patients (86%), usually 10 to 14 years of age, had the combined/predominantly hyperactive subtype, 69% with comorbid disorders, and 97% were treated with medications. Methylphenidate was prescribed in 51%, dextroamphetamine in 17%, clonidine in 20%. and psychotropics other than stimulants in 55%. Patients treated by child psychiatrists were three times more likely to receive dextroamphetamine than those managed by general psychiatrists. Psychiatrists treat a more severely impaired and complex group of patients than those tended by primary care providers. [1]
COMMENT. Compared to patients referred to pediatric neurologists, children with ADHD treated by psychiatrists are generally severely impaired behaviorally and complicated by comorbid oppositional, conduct, and mood disorders, requiring complex treatment regimens. The relatively frequent use of dextroamphetamine by child psychiatrists, and the absence of mention of antiepileptic medication in selected cases were at variance with neurology practice. Epileptiform discharges are reported in EEGs of 7% of 100 consecutive patients with ADHD examined in a pediatric neurology practice, and seizures can be precipitated by methylphenidate and certain antidepressants [2].
ADHD and epilepsy. The indications for an EEG in ADHD patients considered for stimulant therapy include: 1) history of seizures; 2) “daydreaming— or episodic confusion suggestive of absence or partial seizures; 3) family history of epilepsy; 4) abnormal neurologic signs or radiographic evidence of brain pathology. An abnormal EEG in a child with ADHD, when associated with episodic symptoms or neurologic abnormalities, and especially when receiving stimulants or certain antidepressants, warrants treatment with carbamazepine or other appropriate antiepileptic medication.
ADHD, methylphenidate, and Tourette syndrome. A review article from the National Institute of Mental Health, Bethesda [3] tends to minimize the risk of stimulant medication in patients with tics and ADHD. The author's condone the use of stimulants but caution that formal informed consent should be obtained, a practice that could be questioned on ethical grounds, and is probably inappropriate, given the alternative medications available.
An estimated 50 to 80% of patients with Tourette syndrome (TS) have ADHD. In sixteen reports (256 cases) published in the literature between 1974 and 1997, methylphenidate (MPH) is cited as the cause of tics in more than 25% of children with ADHD and special education students. In contrast, only 6% of regular classroom students, not exposed to MPH, have tics. Stimulant-induced tics are doserelated, occurring mainly with larger doses. An increased use of MPH in the USA correlates with the recognition of Tourette syndrome by neurologists and a plethora of reports since the 1970s. Before the introduction of MPH for treatment of ADHD, reference to TS in neurology textbooks was lacking, or classified briefly as a psychiatric disorder (Merritt, 1963). MPH appears to play a major role in precipitating or exacerbating tics and TS. Contrary to the evidence presented in the NIH review, MPH should be avoided in patients with a history of TS, and dosage in treatment of ADHD should be conservative [4].
Buproprion for ADHD and comorbid conduct disorders
An open trial of buproprion in 13 adolescent boys with ADHD, CD, and substance use disorder in a residential treatment program at the University of Colorado, Denver, found improvements in the mean Conners Hyperactivity Index and Daydream Attention scores, sufficient to recommend a controlled trial [5]. Buproprion may also lower the threshold to seizures and is known to provoke tics.