BOOKS ON HEALTH
BOOKS ON HEALTH; Gains in Diagnosing Hyperactivity
By SUSAN GILBERT
Published: June 20, 2000
Diagnosing attention deficit hyperactivity disorder has never been easy. Doctors say that it frequently rests on nothing firmer than judgment calls on difficult questions like these:
Does the kindergartner who cannot sit still and pay attention in class have the developmental disorder, or is he just immature?
Does the first grader who has trouble concentrating on her homework but no trouble concentrating on a computer game have it, or is she lazy?
Does the second grader who is bright but struggling to learn how to read have the disorder, or a reading disability?
But, armed with new findings on the symptoms of attention deficit hyperactivity disorder and the brain abnormalities that cause them, many leading researchers say they can reduce the guesswork of the diagnostic process and, with it, the number of people who are misdiagnosed. The first step, they say, is for doctors and parents to understand that, despite its name, attention deficit hyperactivity disorder encompasses more symptoms than inattention, hyperactivity or both.
''It's not just a disorder of kids who can't pay attention or sit still,'' said Dr. Thomas E. Brown, associate director of the Yale Clinic for Attention and Related Disorders. ''It's more complex than most people think.''
Dr. Brown is the editor of a new book, ''Attention-Deficit Disorders and Comorbidities in Children, Adolescents, and Adults'' (American Psychiatric Press), in which more than two dozen researchers describe findings on the causes and symptoms of attention deficit hyperactivity disorder.
The research underscores two major points that Dr. Brown and his authors consider crucial to making more accurate diagnoses and prescribing medication and behavioral therapies more judiciously. One is that people with the disorder are at very high risk of having or developing various other problems like depression, bipolar disorder, anxiety, learning disabilities and, in adolescence, substance abuse.
In many cases, doctors fail to recognize that a patient has more than one disorder, Dr. Brown said. ''The kid is medicated for attention deficit,'' he said, ''but if he still can't get his homework done he's pegged as lazy because no one realizes that he may also have a reading disability.''
Dr. Brown said that a problem that coexists with the disorder could interfere with Ritalin and the other stimulant medications that are often used to treat it.
The second crucial point in Dr. Brown's book is that many people with attention deficit hyperactivity disorder appear to have chronic difficulty with the brain's executive functions, a term that encompasses short-term memory, planning and staying focused on a task without being distracted by emotional impulses. Seen this way, the disorder does not impair someone's ability to pay attention across the board but rather the ability to keep paying attention despite a lack of interest or frustration.
In one chapter, Dr. Brown and Dr. Rosemary Tannock, a psychiatrist at the Hospital for Sick Children in Toronto, cite studies showing that people with the disorder have structural anomalies in areas of the brain that are associated with executive functions.
The view of attention deficit hyperactivity disorder as a developmental disorder of executive functions, not merely of attention or impulse-control, is gaining ground.
''There's a strong circumstantial case that some individuals with attention deficit have problems with executive functions,'' said Dr. F. Xavier Castellanos, who leads the attention deficit hyperactivity disorder research unit at the National Institute of Mental Health, and whose work is cited in Dr. Brown's book.
One bit of circumstantial evidence is the way that the symptoms change as a child gets older. ''Hyperactivity decreases with age, but symptoms of inattention don't seem to diminish,'' Dr. Castellanos said.
A likely reason, he and other experts say, is that a person's life becomes more demanding and requires a greater use of executive functions.
Further evidence comes from the seemingly contradictory symptoms in individual patients. In particular, many people with the disorder have trouble paying attention in some situations -- when the teacher is talking, for instance, or when they must finish their homework -- but not in others.
''Everyone knows people with attention deficit who can concentrate well enough to play computer games for hours,'' Dr. Castellanos said.
Dr. Michael Gordon, chief clinical child psychologist at the State University of New York Upstate Medical University in Syracuse, notes that everyone has trouble with executive functions from time to time, especially when they are under stress.
''Any of us is potentially disabled if we get ourselves into a competitive situation where our abilities are outstripped by the demands,'' Dr. Gordon said.
But Dr. Brown thinks that recognizing deficits in executive functions as well as the possibility of coexisting disorders can help doctors make more accurate diagnoses.
''Attention deficits are overdiagnosed in some people and underdiagnosed in others,'' he said, noting evidence that it has been underdiagnosed in girls, as well as in adolescents and adults, because they are less likely than young boys to have the most obvious symptoms, hyperactivity and impulsive behavior.
Experts say that parents who are concerned that their child might have the disorder should arrange for a comprehensive evaluation by a pediatrician, psychologist or psychiatrist who is experienced with the disorder.
''You can't do this in one or two sessions,'' said Dr. David Fassler, chairman of the Council on Children, Adolescents and Their Families of the American Psychiatric Association. ''A comprehensive evaluation means getting a detailed history of the child's early development, medical conditions and problems in school and with friends, as well as meeting with the child and the family.''
Photos: More than two dozen researchers contributed to a book about hyperactivity edited by Dr. Thomas E. Brown. (George Ruhe for The New York Times)