Dr. Cindy Taylor

Clinical Psychologist

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Attention Impairment Index - Part 1

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In the late 1990's, we published a research study of the first 500 adults we evaluated for ADHD.  In analyzing the data, Dr. Taylor developed the Attention Impairment Index (AI).  The AI is a measure of overall attention deficits across several different tests and dimensions of attention.  First of all, attention is not a simple thing.  It is widely distributed in the brain and has many different definitions.  One goal of our research was to determine how ADHD Adults were different from other adults with attention problems.  There are many other disorders that cause disruption in one or more areas of attention, so just because one has trouble sustaining attention, does not necessarily indicate that he or she has a diagnosis of ADHD.

For instance, an individual who is anxious will have trouble paying attention, especially in times of higher stress, such as when the boss is talking.   Research on anxious subjects indicates that high levels of anxiety is associated with a general inability to maintain attention.  This is true for individuals with social phobia as well.  Subjects with posttraumatic stress disorder causes the ADHD-like symptoms of hypervigilance, hyperarousal, and poor concentration.  One final anxiety disorder is Obsessive Compulsive Disorder, which can mimic the hyperfocus seen in ADHD, but at least one study showed that these individuals did not show impairment on tasks or immediate memory of focused attention.

Alcoholics and drug addicted individuals will also show symptoms of ADHD.  if stimulants are used, such as cocaine, there will be an appearance of ADHD symptoms or a worsening of symptoms already present.   A lot of research has focused on schizophrenic spectrum disorders, as attention problems are common among this population.  There are also studies indicating that first degree biologic relatives of schizophrenics experience attention problems.  Most affected were the patients with schizophrenia, as they experienced deficits in sustained attention, and greater interference or distractibility.

Other individuals known to have attention problems are those with head injuries.  Milld head injuries tend to cause problems with selective attention, whereas severe head injuries have a variety of issues, including slower speed of information processing.  This processing speed deficit is also common in children with ADHD. 

Chronic fatigue, both symptomatic and asymptomatic HIV positive patients, bulimics, and mentally retarded subjects all showed objectively measured attention deficits or slowed processing speed. Therefore, it was presumed that individuals with more diagnoses will have more attention problems overall. 

Out of the 500 subjects, some were omitted because of incomplete data of IQ scores significantly below average, leaving 470 adults, 272 males and 198 females.  The first interesting finding of this study was that only 68 of the subjects tested had a diagnosis of ADHD only (14%).  Approximately 43% of the sample received a diagnosis of ADHD, but 68% of the ADHD subjects also had at least one other psychiatric diagnosis.   That is really interesting given that most of the individuals were self-referred and came to the evaluation believing that they had symptoms of ADHD.  Part of the problem is that having untreated ADHD for many years can lead to problems keeping a job, failed marriages, impulsive decisions which have negative outcomes on the individual's life; and all these things can lead to depression, substance abuse, legal problems, financial problems, etc.  So, many times, what began as a simple case of ADHD in childhood has evolved into ADHD and many other conditions that also require treatment. 

The subjects were given a comprehensive evaluation including a clinical interview, a measure of intellectual functioning, a variety of attention measures, and a personality test.  The adult subjects also had spouses or significant others complete a behavior checklist about their current behavior, and they were asked to have parents complete a developmental history and report of ADHD symptoms between the ages of 6 and 12 to establish childhood onset of the disorder.   

 Subjects were classified into one of three groups:  No diagnosis (ND), ADHD (ADD), and Other Psychiatric Disorder (OP).  Types of attention measured were attentional flexibility, of the ability to shift attention, sustained attention, overall concentration and processing speed, and selective attention.  A problem on any of these measurements resulted in points being added to the Attention Impairment Index.  A higher AI indicates a more severe attention problem and an AI of 0 indicates that the individual performed within the average range on all of the tests administered. 

Results were as expected in that AI was positively correlated with number of psychiatric diagnoses.  In other words, the subjects with the highest number of diagnoses were having the most severe attention problems.  Measures that most reliably differentiated the ADHD subjects from the others involved sustained attention.  Within the ADHD group, those with the predominantly inattentive type and the combined type had higher AI scores than the ADHD, Hyperactive-Impulsive Type.

Last Updated on Monday, 25 August 2014 23:59  

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