The ADHD Bell Curve

“My seven year-old son is inattentive, off-task, distractible and has a short attention span. At home, he hops from one activity to another, never picks up anything … sort of an energizer bunny. The school suggested that we have him tested for ADHD. Does he have ADHD?”

“I was told (I love this one because the person who told them is never identified) that if your child was a climber as a toddler, then they have ADHD, that you can tell true ADHD in a child if he cannot fall asleep at night … if he stays up late.”

My first thought?, to be redundant, the doctors and nurses at the hospital should have told you about these things when you brought the baby home from the hospital. Children are inattention, they do not stay on task, they hop from one activity to another. Toddlers climb and infants are not always great sleepers.

The issue is not whether a child demonstrates or does not demonstrate a specific behavior or problem, but whether the frequency, duration and/or intensity of identified behaviors or problems are within the middle of the bell curve (the norm).

An understanding of the bell curve is critical to the concept of diagnosis. Ever heard of the bell curve? Well, this is what we know; all human performances (what people do) follow the normal bell curve. An example, a few people are fast, a few people are slow, but most people fall within the middle. A few people are strong, a few people are weak, but most people fall within the middle. The bell curve can be graphed as performance (horizontal axis) by the number of people (vertical axis) and when we graph these two factors, the graph looks like a bell with the highest number of people falling in the middle (called the mean) and progressively fewer people as one moves towards the extremes or tails.

The task is not to identify whether your child is inattentive (because we know that he is) but how much does his inattention (performance) differ or deviate from the mean or average child of the same age.

It turns out that not all children who are average fall exactly on the mean so we need to establish a “tape measure” to determine how much a child deviates from the mean. This measure of deviation from the mean (or “gold standard”) is called the standard deviation. About 2/3 children fall within about one standard deviation above or below the mean. This group of children is called the “middle of the bell curve” or average range.

So, does your child have clinically significant features of inattention? It depends on how much his behavior or problems differ from the mean. Behaviors that deviate from the norm by more than two standard deviations (less than about 5% of the children) are generally labeled as having features that are clinically significant or important. While the presence of clinically significant or important features of inattention (more prevalent than about 95% of children) is important to know, it still does not nail down an ADHD diagnosis.

My point? Objective measurements of behaviors or problems with subsequent comparison to age norms (bell curves by age) is the first step in understanding whether a behavior is a clinically significant issue. In the absence of standardized observations and normative comparisons, the diagnostic process boils down to the “mean” and “standard deviation” that that the professional has in his or her head based on clinical experiences. Maybe part of our confusion regarding diagnostic processes is because each clinician develops his or her own norms (means) including normal ranges (standard deviations) without recognition of their inherent bias.

Do your child’s behavior problems fall within the norm? Does your child still drive you crazy even if it’s not clinically significant? Hmmmm…the doctors and nurses should also have told you about that part too!

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Dr. Richard Dowell is a Neuropsychologist located in Pennsylvania. Dr. Dowell evaluates upwards of 400 children and adolescents each year. In addition, Dr. Dowell is recognized as one of the top Forensic Neuropsychological witnesses in the North East.

Dr. Dowell can be contacted at DrDowell@NeuropsychologicalServices.net

For more information on Neuropsychology visit NeuropsychologicalServices.net

Defiant Johnny

“Johnny is oppositional and defiant! He doesn’t listen… and when you tell him “no” or to do something, he explodes… he screams, hits, kicks… he used to bite… but now he generally just throws things and yells at me. We’ve been at this since he could walk (unspoken: “… and we are very tired”). I can’t even leave him at school (the respite center for most parents)… they call a couple times each week with more complaints… he doesn’t stay in his seat, he doesn’t listen, he hits other kids… plays too rough on the playground. He saw a couple counselors but nothing helps.” This scenario, in various terms by various parents, plays out during the initial screening about 200-300 times each year in our clinic (from among 400 referrals). Interesting (to us), but frustrating to the parents, Johnny sits stoically during the recitation of his “crimes” with nary a complaint nor hint of the symptoms that are tearing this parent (and usually family) apart. Occasionally a parent may go so far as to prod the child into a negative response simply to show that they (the parent) are not lying. Other parents support their argument with a recitation of the teachers, service providers, family, etc. that have been ravaged by their child’s behaviors and concluded the ominous diagnostic verdict, “Your child has oppositional defiant disorder.”

A child who is oppositional and defiant has “oppositional defiant disorder?!?” As professionals, we may need to guard the diagnostic secret that all we do is say “disorder” after the child’s symptoms! Given this line of reasoning, secondary diagnoses for this child could include “scream disorder and kick disorder.” Labeling the child’s symptoms as “oppositional defiant” does not advance understanding of the etiology of symptoms nor potential treatment avenues. Unfortunately, this scenario plays out millions of times each day for children across the country with similar conclusions. The primary cost of this labeling approach to diagnoses is that it tends to result in termination of the search for the underlying etiology or cause for the presenting symptoms. The solution… complete an evaluation or assessment to search for factors that may contribute to the symptoms.

Existing research irrespective of diagnosis indicates that outcomes are related to three factors including: (1) abilities (ie., “hardware” or central nervous system-based processing capacities), (2) skills (ie., acquired responses based on the environment including academic skills, daily living skills, social skills, etc.) and (3) coping resources (ie., “software” packages written by a child in response to the world in which they live). Given this background, a logical extension is that failures of positive outcome (ie., oppositional defiant behaviors) must similarly be related to limitations or deficits related to abilities, skills and coping resources.

What about Johnny? Test results showed strengths across measures of verbal (language), perceptual-motor, learning/memory and higher level reasoning abilities. In contrast, deficits were observed across measures of lower level executive or “conductor” functions including: (a) inhibition (b) rhythm/background tone and (c) “select” (ie., multi-tasking, shifting mental sets, etc.) functions. Deficits in inhibition (or disinhibition) were reflected across external stimuli (ie., short attention span, distractible, etc.), motor responses (ie., hyperactive, hurried, fidgeting, messy, etc.), behavior (ie., rule violations), mood/emotions (ie., irritable, anger, temper tantrums, etc.) and arousal level (ie., difficulties falling asleep, constant motion, broken sleep, etc.). Poor rhythm/background tone was reflected in low frustration tolerance and difficulties adapting to change. Deficient “select” functions were reflected in difficulties with respect to multi-tasking (ie., performing two tasks at once or in rapid/alternating succession) with a high frequency of off-task behaviors (ie., failure to complete assignments, requirements for re-direction and difficulties completing assignments on time). The conclusion…. Johnny’s collection of symptoms/problems (his “ODD”) was related to a breakdown in abilities that warranted a similarly biologically-based (central nervous system) intervention program foundation. Research suggests that an estimated 90% of children with this profile (who also meet ADHD criteria) show benefits to psychostimulant medications.

My Lazy Kid

“Teachers have been telling me that my child is lazy and that if only she just worked harder, was more motivated, etc., then she could do very well. We have responded by setting aside daily study times, requiring her to complete all homework before going out to play, providing her with stars for success, taking away all video games and grounding her for poor grades. Our interventions have resulted in study times that take all night, angry outbursts, depression (“I just wish I was dead”), loss of friends, no free time and… poor grades. Help!” The parent saying these words generally looks the part of the beleaguered parent with the wear and tear of endless nights of battles over homework and being the target of child anger being etched in their face.

Hmmm….. First, a quiz. Which would be easier? To put in forty-five minutes of study time, go out and play, be the recipient of parental praise and have extended free time… or… take four hours to complete a homework assignment while having your parents relentlessly harass you, lose privileges, have your videogames taken away, lose friends and have no free time to play? I’m thinking that it would be much easier to just do the work in the shortest amount of time and receive the benefits… and so would every child. Present to each child in school (through about age 12 years) a request that “Who ever wants an “A” in all their classes for this year, just raise your hand” and you will see 100% compliance or agreement. If the ante was raised slightly, “Who ever wants an “A” in all their classes for this year, raise your hand and walk around the track one time (400 meters)” and you may see a slight reduction in compliance. How about “Raise your hand, walk around the track one time and run the 100 yard dash in under 11 seconds” and you will begin to lose some more hands.

The point?…. everyone wants success, but at some point the child may not have the tools to achieve that success. For the child that is working four hours while screaming and crying, losing privileges and enduring parental harassment, these conditions are obviously more readily available than success by studying 45 minutes. I see about 350 children each year… and during the past 20 years, I believe that I have seen about three “lazy” children (and each of these were adolescents with psychopathic features). The rest? The rest were children with undiagnosed learning disorders that have variously included deficits in attention, visual-spatial processing, visual-motor integration, auditory processing disorders… or children that were the victims of significant life stressors, neglect, deprivation, etc. that undermined their capacity to translate abilities into “real world” performance on a consistent basis.

Your child has been labeled “lazy”? Consider the probability that your child has an undiagnosed learning disorder or other stress-related disorder. The solution… consider having a formal evaluation completed to rule out this potential.

My Child is Inattentive and Hyperactive

“My child is inattentive and hyperactive!” I hear this as a presenting complaint about two hundred times each year (from among our clinic’s 400 referrals each year). My first response (after my unspoken… “And?!?!… you had to have been told something about children and this behavior before becoming pregnant?”) is to tell parents that all children (and adults) are inattentive and hyperactive. The question is, “How much does the inattention (or hyperactivity) differ from the norm?”. Einstein aptly informed us that “all is relative” and that a behavior cannot be understood independent of the observer. A parent who exhibits significant symptoms of inattention and hyperactivity may perceive similar child symptoms as the norm. A parent who resides within a chaotic, unpredictable and inconsistent home environment may not recognize features of inattention as a problem. The symptoms defined as the “norm” in one home or “not a problem” in another home may be perceived as disruptive, disabling or catastrophic to the parent whose world corresponds to a Franklin Covey Day Planner. The central role played by the parent (observer) in the diagnostic process is obviously problematic since the presence of a diagnosis is potentially more dependent upon the parent than the child.

The solution to the dilemma introduced by observer bias is the use of standardized tests to assess processing capacities/abilities and deficits/impairments. Standardized tests are measures (or tests) that are presented to children (or adults) using a standardized (consistent, predictable, etc.) method with specific (standardized) instructions to maximize consistency among observers (testers). The diagnostic task is to identify whether the presenting symptoms/complaints (ie., inattention, hyperactivity, etc.) are part of the normal bell curve (within the norm for children the same age) or are outside of the normal bell curve relative to the child’s peers.

All human behavior or performances tend to be normally distributed such a low number of people exhibit a high level of performance, a low number of people exhibit a low level of performance and most people fall in the middle. As an example, a few people are very fast, a few people are very slow, but most people fall in the middle. A few people are very strong, a few people are very weak, but most people fall in the middle. Standardized tests are simply measures of behavior or performance and, as a result, performance on tests is normally distributed with a few children scoring high and low, and a large number of children scoring in the middle. Within the standardized testing method, observations obtained on a single child are compared to this normal bell curve. The task is to identify the extent to which the child’s behavior deviates from the norm. Definitions (often referred to as “cutoff scores”) regarding what constitutes abnormal behavior or the presence of a disorder differ. However, most clinicians tend to classify scores that deviate from the norm by over two standard deviations (ie., observed among less than five percent of children) as abnormal or of sufficient severity to warrant a “disorder” diagnosis.

So… is “my child is inattentive and hyperactive?” The answer is “yes”… and so are you. “Does my child’s inattention and hyperactivity deviate from the norm sufficiently to be an impairment relative to the demands of the normal environment (home or school)?” The answer is “I don’t know” and it is very unlikely that any other single observer will have the answer to that question (including physicians, psychologists, etc. are also biased observers). The solution… complete an evaluation that utilizes standardized measures.

Symptom-based diagnostic models

You enter your physician’s office holding your head from a throbbing headache. The nurse cordially smiles at you and takes you to an examining room. Minutes later (hey… this is my dream… I can keep the wait short)… the physician enters the office. You inform him or her that you have a headache. Your physician gives you a long look, sighs then pronounces the diagnosis “You have a headache disorder!” Nonplussed, huh? Thinking that perhaps its not too late to get your co-payment back?

Unfortunately, each day millions of parents take their child into offices of physicians, psychologists, therapists, etc. proclaiming that their child has a deficit in attention and is hyperactive and are told by well-meaning professionals, “Your children has an attention deficit hyperactivity disorder!” Nonplussed? I hope so. Attention deficit hyperactivity disorder is a symptom-based diagnosis much like a “headache disorder” would be a symptom-based diagnosis. The unfortunate aspect of this scenario is that labeling the symptom (ie., “headache disorder”) does not explain the underlying cause or etiology of the symptom. Headaches are non-specific symptoms and may be related to underlying etiologies ranging from muscle tension, cervical neck strain, migraines, cluster headaches, increased intracranial pressure, hemorrhagic strokes to brain to tumors. As a patient-consumer you (and your physician) want to know the underlying cause of the headache so that subsequent treatment may be directed towards the cause, not simply the symptom, of the headache. Similarly, inattention, distractibility, off-task behaviors, restlessness, etc. are non-specific symptoms. A review of the DSM-IV-TR (Diagnostic and Statistical Manual – IV Text Revision) and other diagnostic manuals reveals that this cluster of symptoms is consistent with multiple diagnoses ranging from anxiety, depression, Tourette’s Syndrome, post-traumatic stress disorder, neurologic disorders, pervasive developmental disorders to learning disabilities.

The unfortunate effects of this symptom-based diagnostic model of “ADHD” include: (a) the simplistic labeling of symptoms (ADHD) with resulting termination of the search for an underlying cause, (b) evaluations that are limited to symptom counting, (c) a delay in the development of effective intervention plans among children with more pervasive developmental disorders or other deficits, (d) utilization of the child’s response to medication as a tool for confirming the accuracy of the diagnosis and (e) the “mis-diagnosis” of children with resulting public perceptions that oftentimes effective medications (ie., psychostimulants) are of no value or counter-productive. The solution… hmmm…

See you next week.