I evaluate children, adolescents and adults referred for the question of ADHD diagnosis. One of my favorite questions for adults is: "Have you read the book Driven To Distraction?"(Halowell, 1994). A typical response: "I started reading it Doc, but got distracted and never finished it!" Does this cap a diagnosis of ADHD? No, but it's amusing. The real challenges are: defining ADHD, understanding the subtypes, differential diagnosis, intervention strategies and further research.
The acronym "ADD" no longer exists in DSM-IV (Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition) or most diagnostic manuals and textbooks. Attention Deficit Hyperactivity Disorder (ADHD) now applies to both the hyperactive and non-hyperactive types. DSM-IV lists four subtypes of ADHD: Inattentive, Hyperactive-Impulsive, Combined and Not Otherwise Specified. Years ago, it was believed that a child must be hyperactive to have "ADD". Boys outnumbered girls 4:1, as they tended to display greater hyperactivity. The ratio is now closer to 2:1 with the advent of the non-hyperactive variety attributed more girls with ADHD. Recent estimates suggest that 5% of the general population may have ADHD. This implies that many individuals, particularly adults, were never diagnosed, but manifested symptoms as children that have persisted to adulthood. When news of adult ADHD hit the media, a large influx of individuals contacted our office for evaluation and treatment.
PET scan studies have identified three neurotransmitters (dopamine, serotonin, and norepinephrine) that are depleted in individuals with ADHD. Dopamine plays a critical role in attention and concentration, with serotonin and norepinephrine affecting mood. One theory about ADHD is that diminished dopamine leads to chronic"under-stimulation". The hyperactive-impulsive subtype will seek out stimulation (many times to their detriment) to compensate for under-stimulation. This may account for living on the edge, risky behaviors, and impulsive actions designed to stimulate an otherwise sluggish attentional system. To the extreme, impulsive behaviors serve to create conflict and trauma for the individual. They achieve a high level of stimulation, but at the expense of self-sabotage. Statistics note that hyperactive-impulsive boys have, on average, two misdemeanors by age 14. Their female counterparts, on average, have four times the national average of pregnancy by age 16. One-third of hyperactive-impulsive individuals are substance abusers (typically marijuana and cocaine) to self-medicate dopaminergic stimulation. Many do not complete high school, with even fewer completing a college education. The pattern of instability persists in adulthood. Frequent job changes (e.g., 20 jobs in 5 years), living at home with their parents (in their 30's), multiple divorces, bankruptcy, projects started and left undone, and chronic substance abuse are some of the sobering trends. In my opinion, the hyperactive-impulsive subtype has the poorest long-term prognosis of all four subtypes. Some of these individuals are charged with criminal activity resulting from impulsive acts (which may also correlate with a high incidence of co-morbid Oppositional Defiant Disorder).
In the past few years, some defense attorneys have requested my "expert" assessment that their clients' ADHD behavior "caused" them to commit various crimes (petit larceny, breaking and entering, burglary). The "Twinkie Defense" comes to mind (e.g., suing McDonalds because their food caused a person to become obese). I was asked to consult on a case where an ADHD young adult broke into a pizza establishment at 1:00 a.m. because he was hungry for chicken wings. Amazingly, despite the security alarm alerting the police, the ADHD perpetrator did not run away, as the wings were not fully cooked. He was arrested, wings (medium hot sauce) and all. This is a great example of impulsivity and very poor judgement for good measure. Though I will evaluate and promote appropriate treatment for ADHD individuals, I also believe taking personal responsibility for one's actions is an important developmental life skill.
The Inattentive ADHD individual is quite different from the Hyperactive-Impulsive subtype. They are often described as: "daydreamers," disorganized, visually inattentive and/or forgetful (e.g., misplacing keys, wallet), slow to initiate and complete tasks, and as having difficulty with time management. Literature reviews and case studies (e.g., Wasserstein, 2001; Halperin et al., 2008) have suggested possible right hemispheric dysfunction in Inattentive subtypes paralleling similar attributes with Non-Verbal Learning Disabilities (NVLD). Recent articles have coined the term "sluggish cognitive tempo" to describe the Inattentive Type. Generally, Inattentive children and adults do not exhibit hyperactivity (likely resembling the old ADD type) or highly impulsive behaviors. I observe some co-morbid anxiety, obsessive-compulsive behaviors, and mood disorders in this group who may improve with psycho-stimulants and/or SSRIs (e.g. Fluoxetine). The perception of time seems "off" with these individuals (e.g., what ten minutes "feels" like). Using specific time frames for an activity (while the child or adult refers to a digital watch) may improve initiation and perception of time with task completion.
Treating the Combined Type of ADHD is quite challenging. Patients exhibit both Hyperactive-Impulsive behaviors and Inattentive features. They are risk-takers living on the edge who are not always vigilant of their surroundings. Thoughts of George of The Jungle come to mind ("watch out for that tree!"). Many accidental traumatic brain injury children I evaluated over the years had a pre-morbid history of ADHD. This may relate to the statistic that ADHD children have a four-fold greater chance of sustaining a serious brain injury due to accidents (e.g., not looking both ways when crossing the street) compared to non-ADHD children.
The Not Otherwise Specified subtype of ADHD is likely not utilized by clinicians very often. This subtype is basically anyone who does not fulfill criteria for the other three. This subtype may in fact be one of the other three, but in a milder form. ADHD subtypes seem to be on a continuum. Often the rule of thumb is, to what extent is the condition disabling or limiting the individuals' social, educational and vocational potential? It is important to ask this question when interviewing a patient (and family members) as the patient may be compensating quite well for their ADHD challenges. I suspect that well before ADHD became a chic diagnosis, some individuals developed their own home grown methods to compensate for their difficulties (and strict teachers who, according to some patients, used inappropriate methods to gain a student's attention, such as striking their knuckles with a ruler).
In my opinion, misdiagnosis (and overdiagnosis) of ADHD certainly exists. In some clinics, an individual can report a laundry list of ADHD symptoms (often derived from the Internet) and walk out with a controlled substance prescription 15 minutes later. Another scenario is the double-blind method of diagnosis. Two packets, A and B, are given to a parent. One packet contains medication (e.g. Ritalin), the other, a placebo. For week 1 packet A is administered, week 2 packet B. Parents and teachers are "blind" to which packet contains medication. The child's performance is rated in class. If the child is more attentive when the medication packet was administered (with no behavioral change during the placebo trial), lo and behold they must have ADHD! Science is a wonderful thing! The problem is, most people (who are not ADHD) would experience improved attention and concentration with a psycho-stimulant; it is a matter of degree. This may be one reason ADHD is over-diagnosed and over-medicated. So how can we improve the accuracy of ADHD diagnosis?
We do not (yet) have a blood test for ADHD. PET scan studies are highly expensive and used mostly as a research tool. Most neuropsychologists would agree that one systematic, objective test does not yet exist to reliably diagnose ADHD. The research on ADHD neuropsychological testing protocols is promising as some trends are evolving (e.g., potential right hemispheric dysfunction in Inattentive subtypes). It is also important to distinguish ADHD (familial?) from acquired forms, arising from TBI or perhaps toxins. Some research has suggested a possible link of mothers smoking during pregnancy and having a ADHD child (incidentally, ADHD mothers may have a higher incidence of smoking cigarettes thus the child's ADHD may be familial).
Many physicians require their patients undergo testing to confirm an ADHD diagnosis. In my practice, neuropsychological ADHD testing includes: clinical interview of the patient and family members, review of school/work/medical records, and measures of: intelligence, working memory, short-term memory, visual-motor development, perceptual organization, tests of vigilance (both auditory and visual of increasing complexity), achievement, central auditory processing, executive functions, simple and divided attention, personality assessment, and behavioral assessment scales. This in-depth examination objectively measures various components of information processing and attention/concentration compared to the individual's overall abilities. Statistically significant differences between ability and measures of ADHD attributes (while ruling out other potential causes for diminished attention) aids the objective diagnosis. I am analyzing neuropsychological test data collected on my ADHD patients over the past ten years. If specific tests cluster and have predictive power or loading on ADHD behaviors, a systematic testing battery may emerge.
When a diagnosis of ADHD (and subtype) is rendered, the findings and recommendations are shared with the patient, family (when appropriate and consented), and primary care physician. Medication options, if advised, are discussed. In school-aged children, various accommodations are integrated with a 504 Plan or Individualized Education Plan. For adults, job modifications or the services of a job coach may be needed. The suggestion of individual and couples therapy may also emerge to help educate and navigate the ADHD behaviors. Balancing these recommendations can be challenging, depending on the subtype, and if co-morbid psychological issues (e.g. anxiety, OCD behaviors, mood dysfunction) are part of the equation.
Our knowledge of ADHD is expanding. As with any clinical condition, keen observation, rigorous research and education is important. I am in the process of completing my first book on various clinical conditions through the stories of my patients. One of the chapters is dedicated to pediatric and adult ADHD. I am grateful to these patients for allowing me to share their stories.
Peter B. Sorman, PhD, ABN
Board Certified Clinical Neuropsychologist
Diplomate, American Board of Professional Neuropsychology