The following information was obtained during a lecture by Joseph Beiderman, M.D., Professor of Psychiatry at Harvard Medical School, and a noted researcher in the field.  His topic was: "The Neurobiology, Diagnosis and Treatment of ADHD Across The Life Cycle."  As will be seen from the scope and variability of the information,  my commentary which precedes it in this section remains relevant.  All medical care requires a diagnosis, including a differential diagnosis, before comprehensive treatment is embarked upon.  And when the diagnosis remains in doubt, it is better to call  the situation “diagnosis undetermined” rather than to label it prematurely and thus  terminate the critical thinking of others in the matter.
 

• This diagnosis, with even its own DSM lV code, includes a heterogeneous group of conditions with multiple possible etiologies: neuroanatomic / neurochemical, central nervous system, genetic and environmental.
• Estimated prevalence in children is 5%.  There is a lower incidence in Ireland; there is a higher incidence in Puerto Rico, Spain, and in the Netherlands. (??)
• The symptom areas include: inattention; and impulsivity / hyperactivity.  The symptoms often vary in pervasiveness and in frequency of occurrence.   30% of ADD/ADHD patients do not have hyperactivity.  Subtypes include combined-inattention-impulsivity.
• Pathology: the pre-frontal cortex is the main site involved in ADHD, followed by the anterior cingulate gyrus.  The pathophysiology is a dysfunction of dopaminergic pathways.  PET scans can show pre-frontal and motor activation disturbances, in addition to smaller size of the implicated brain areas.  However, MRI and PET studies are not yet useful clinically.
• It has recently been found that the cerebellum is much more involved in cognitive issues than earlier recognized. (?)
• “Genetics accounts for 80% of ADHD; this is a highly familial illness (6Xnormal)”.  Furthermore, twin studies show some further correlation with bi-polar affective disorder and with schizophrenia.
• Non-genetic issues account for 20%.  The most common is maternal smoking during pregnancy; other factors include fetal alcohol exposure, low birth weight, and psychologic adversity.
• Co-Morbidity:  ADHD tends to be associated with other diagnoses in the same individual: oppositional - destructive behavior, conduct disorder, mood - anxiety and learning disorders. (Much more prevalent in males).  Also bi-polar disorders in 10% of ADHD. Also drug abuse starting in adolescence, perhaps to a greater degree in girls.
• Remissions in ADHD: there is no sure pace for remissions.  The sequence seems to be: hyperactivity first, then impulsivity, and then inattention.  Remissions may occur in up to 60% of those affected.
• Predictors of persistence: positive family history; co-morbid conditions; psycho-social issues.
• “ADHD is a valid diagnosis for adults”.  “It is estimated that 25% of criminal inmates may have ADHD”.
• Treatment:  “Medications are fundamental to the treatment of ADHD; treatment works, as distinguished from only behavioral and/or community-based treatment”.  Best are the drugs ritalin, dexedrine, adderal, cylert... One-third of patients respond selectively, to one or to the other of these agents.   One-third of children do not respond or can’t tolerate these medications. The main alternatives are the tri-cyclics.

GS