Kelly Scott Moroz, July 2010Differentiating Types of ADHD Subsets: More than just Semantics

Many psychologists, including myself, involved in the assessment, diagnosis, and treatment of individuals with Attention-Deficit/Hyperactivity Disorder (ADHD) are awaiting the publication of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in May 2013. In the DSM-IV (1994) and the DSM-IV TR versions (2000), ADHD is outlined as displaying difficulty with attention, hyperactivity, and/or impulse control relative to children of the same age and sex. Attention is regarded as a multi-dimensional construct that refers to problems with alertness, selective or sustained attention, and distractibility. Children with ADHD are likely to have their greatest difficulties with sustaining attention to dull, boring, and/or repetitive tasks; and tend to be more active, restless, and fidgety than typical children. Challenges with impulsivity are evidenced when these children are expected to focus on their main objective in the face of more immediate rewards and gratification. To meet the diagnostic criteria for ADHD, the individual must exhibit at least six symptoms of Inattention (from a list of nine possible symptoms) and six symptoms of Hyperactivity-Impulsivity (from a list of nine possible symptoms). Combined Type ADHD is the diagnosis for individuals who meet the required six symptom cut off in both the Inattention and Hyperactivity-Impulsivity domains. Conversely, individuals who only meet the Inattention criteria are diagnosed with ADHD Predominantly Inattentive Type, while individuals who only meet the symptomology threshold in the Hyperactivity-Impulsivity area are diagnostically referred to as ADHD Predominantly Hyperactive-Impulsive Type. Over the past decade, some of the more recognized gurus in the field of ADHD research now believe that the Predominantly Inattentive and Predominantly Hyperactive-Impulsive Types of this disorder need to be revisited, both in the areas of assessment and treatment (e.g., Barkley, 2008).

In Barkley’s Attention-Deficit/Hyperactivity Disorder - Third Edition, he indicates that hyperactivity evidenced in ADHD Predominantly Hyperactive-Impulsive Type children might better be conceptualized as an early developmental manifestation of a more central deficit in behavioural inhibition; a younger version of individuals with the Combined Type of this disorder. In my own experience over the past decade, I too have noticed that symptoms of hyperactivity tend to decline significantly across the elementary school years, while issues with inattention and task completion seem to remain stable or heighten as these children progress into their later elementary and junior high schooling. The Inattentive Type of ADHD has also become better understood since the DSM-IV was published in 1994. In fact, many experts feel that the Predominantly Inattentive Type may constitute an entirely different and distinct disorder (Barkley, 2008), that is very different from the Combined Type. Common presenting symptoms of individuals diagnosed with the Predominantly Inattentive Type (compared to the Combined Type) include appearing more hypoactive, lethargic, increased levels of daydreaming and staring off behaviours, appearing easily confused and mentally foggy, and appearing socially reticent or withdrawn. These individuals do not evidence significant issues with impulse control (by definition), and rarely with opposition and misconduct; rather, they appear to evidence a greater risk for anxiety and possibly depression. From a treatment and management perspective, a “one size fits all approach” to the treatment of ADHD children and teens is not in the best interest of the client. There are clear differences as to what will likely prove successful therapeutically within each subset.

At our office, we notice that children and teens with either Inattentive or Combined Type ADHD respond well to support in the areas of filtering out distractions (e.g., using ear buds or headphones, or being seated in a way that reduces visual distractions), the utilization of concrete timing devices (e.g., Time Timer clocks) to help better gage the concept of time and adjust work rate appropriately, and support in breaking down larger tasks into a series of more manageable smaller chunks; these chunks are then plotted directly into an agenda based system.

I find that successfully working with children and teens presenting with Combined Type ADHD will require brainstorming around the implementation of incentive based systems. It must always be noted that neurologically, these children are programmed to seek out more immediate rewards and gratification; working longer and harder for larger rewards does not come naturally to these children and teens. Leaving their seats frequently, shouting out, avoiding tasks, and even instigating others often feels powerfully rewarding for these children, even when strategies such as “movement breaks”, and the use of “blurt books”, to help them think and reflect before speaking, are implemented. I have come to the understanding that these types of strategies are unlikely to prove successful unless some form of rating system/token economy system is continually incorporated. At school, these children seem to work much more independently when the teacher is involved in this reinforcement process. This means that he or she would rate the child (e.g., on a sticky notepad that gets sent home with their agenda) several times a day on one or two target behaviours (e.g., raising their hand before responding, having their desk area more organized). Research has proven that a very high proportion of individuals with Combined Type ADHD respond extremely well to stimulant medications (e.g., Barkley, 2006). These stimulant medications mainly include the longer acting version of Ritalin (eg., Concerta, Biphenton) and Dexedrine (e.g., Adderall XR, Vyvanse). Aside from their longer acting daily effects, these medications are now recognized for their sensitivity to side effects.

Successful treatment for children and teens presenting with Inattentive Type ADHD seem to revolve around a stronger emphasis on organization strategies. Using software such as Boardmaker, laminated charts can be created to remind youngsters of their daily routines in several areas (e.g., a bathroom chart that outlines the steps to proper hygiene; a chart in the entrance way reminding children to put their shoes away, hang up their jackets, pull out their lunch kit, and agenda). As these children age, organizational devices such as iPhones now seem more appropriate, as reminder alarms can be set several times throughout the day. Children and teens with Inattentive Type ADHD also appear to have a better response to social skills training, such as how to maintain stronger eye contact, look more interested and interesting, and how to engage in small talk. More importantly is the fact that newer research is indicating that these children respond much better to the non-stimulant medication Strattera; approximately 80% of individuals diagnosed with Inattentive Type ADHD stop taking stimulant medications within the first five years (Barley, 2008). The much higher success rate with the non-stimulant Strattera might have something to do with the fact that this medication appears to help alleviate anxiety in ADHD children, teenagers, and adults.

The website discusses a few different diagnostic proposals for the current condition, Attention-Deficit/Hyperactivity Disorder. Although, at present, it appears as if the diagnostic category in the newer version of the DSM may only focus on adding four more possible symptoms of impulsivity to be considered in the mix, my hope with this article is to highlight the reasons for vigilance in differentiating between Combined Type and Predominantly Inattentive Type of ADHD, particularly from a treatment perspective. Despite the small differentiation semantically between the two labels, the two types of this condition are indeed different entities, and successful treatment will require strong consideration of these differences.

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