Target Symptoms, Not Diagnosis, Should Guide PDD Drug Therapy. (Neurobiologic Rationale)
Sherman, Carl, Clinical Psychiatry News
NEW YORK -- The pharmacotherapy of children and adolescents with pervasive developmental disorder is best guided by target symptoms, rather than diagnosis, Dr. Robert Hendren said at a psychopharmacology update sponsored by the American Academy of Child and Adolescent Psychiatry.
This approach is more solidly grounded in neurodevelopmental principles and cuts through often knotty issues of classification, said Dr. Hendren, chief of the division of child and adolescent psychiatry at University of California, Davis, Medical Center, Sacramento.
Early identification and treatment of children with pervasive developmental disorder (also known as autism spectrum disorders) have substantial benefits: Developmental progression can be enhanced, both by improving interactions with the environment and possibly by exerting a normalizing influence on neurobiology Reducing symptoms may prevent kindling and sensitization.
Psychotropic medications are commonly prescribed for this population: In one group of 109 children, 55% were taking at least one drug, and 29% were raking two or more. Antidepressants were most often given, but stimulants and neuroleptics also were widely used.
Diagnosis is often problematic, particularly in the less impaired end of the spectrum: Attention-deficit hyperactivity disorder; obsessive compulsive disorder; tics; and mood, anxiety, and psychotic disorders may be difficult to distinguish from or may be comorbid with Asperger's syndrome and high-functioning autism, he said.
"When we don't know the diagnosis, we aren't sure what drug to give. A more useful model to look at is symptom domains," Dr. Hendren said.
One domain of particular importance is inattention, but this must be evaluated with care, distinguishing distractibility, which responds to stimulants, from lack of arousal, which does not.
Distractibility, an executive function deficit, appears to involve dopaminergic and noradrenergic systems in the reticular formation, prefrontal cortex, and corpus callosum, and is best treated with methylphenidate or dextroamphetamine, he said. …