Specialized tests and tools that help to identify and diagnose adult ADHD
In the previous sections, we discussed the various diagnostic challenges that face a clinician when evaluating an adult for ADHD. Fortunately, there are several specialized tests and tools that aid the evaluation process.
To guide the interview and assessment process, the clinician may use a variety of written questionnaires, checklists, and interview protocols. As you may recall, although an adult may receive a diagnosis of ADHD, there must be evidence of childhood symptoms before the age of 12. Therefore, these tools provide a standardized set of questions that serve to structure the memory recall process about childhood symptoms.
Some of these tools are quick and efficient screening tools. Screening tools are brief tests used to rapidly identify someone who might have ADHD. This helps clinicians decide whether to proceed with a more costly and thorough evaluation. The results from these test and tools are alone insufficient for a definitive diagnosis. However, the information gathered from these tools can be extremely helpful in the evaluation process. Now we will review some of these tools:
Adult ADHD Self-Report Scale Symptom Checklist (ASRS)
The ASRS Symptom Checklist is a screening tool. It helps doctors and their patients decide if a more comprehensive ADHD evaluation is warranted. It evaluates 18 symptom criteria. Six of the questions have been identified as the most predictive symptoms of ADHD.
Barkley Adult ADHD Rating Scale - IV
This is another quick screening tool used by physicians and mental health professionals alike to identify adults who may need further evaluation for ADHD. The rating scale takes 5-7 minutes to complete and the Quick Screen tool takes 3-5 minutes. The scale consists of questions about both current and past symptoms. It uses a scoring system from Never (0) to Very Often (3). Research indicates that a high score suggests a strong likelihood of ADHD.
Brown ADD Scales (Adult)
This 40-item, self-report measure is a quick way to screen for adult ADD. This scale uses the term ADD to reflect the fact that it does not examine hyperactivity/impulsivity symptoms. Instead, it focuses more on evaluating inattention and executive skills. It also helps to identify which executive function skills might be impaired LINK TO EXECUTIVE FUNCTION. This evaluation tool focuses on six key skill areas: 1) sustained attention; 2) sustained effort for task completion; 3) activation of organizational skills needed to complete tasks; 4) recollection of learned material; 5) utilization of short-term memory; and, 6) mood regulation. These executive functioning skills are often poorly developed in people with ADD. This evaluation can be completed with paper and pencil, or with digital software. The digital software version includes comparison with age-based normative data. Significant deviation from what is average for a person's age would suggest a problematic skill area.
Connors' Adult ADHD Rating Scales (CARRS)
These scales can be used to assess inattention, hyperactive-impulsive behaviors, and overall ADHD symptoms in adults over 18 years of age. CAARS provides a self-assessment form for the patient. It also includes forms to be completed by people who might have useful information about the patient (e.g., family members). Thus, CARRS collects data from more than one source. Both versions contain 66 items, including nine subscales. The results can also help to determine which respondents might benefit from a more thorough evaluation.
Copeland Symptom Checklist for Attention Deficit Disorders - Adult Version
This checklist is designed for adults (18 and older). Like the children's version, the Copeland Symptom Checklist (adult version) assesses the severity of symptoms in eight areas. These are: 1) emotional difficulties; 2) peer relations; 3) family relationships; 4) attention skills; 5) impulsivity; 6) activity level; 7) organization or learning problems; and, 8) degree of compliance.
Wender Utah Rating Scale (WURS)
The Wender Utah Rating Scale assesses ADHD-relevant childhood behaviors and symptoms in adults. It was designed to aid in retrospective identification of childhood ADHD in adults. The most recent version consists of 25 items. The WURS does more than simply identify people with ADHD. It also helps to differentiate between persons with ADHD versus people with Major Depression. The symptoms of these two diagnoses overlap so this differentiation is very helpful. Moreover, it helps to identify people who may respond well to an ADHD treatment with a drug called Ritalin ® versus those who may not. LINK
Once an initial assessment of developmental history has been completed (via interviews, questionnaires, and checklists) additional tests may be needed. The initial assessment phase will often raise questions about alternative diagnoses that might better account for the symptoms. Before ADHD diagnosis can be made, these alternative diagnoses must first be considered and then ruled out:
- A medical exam may be needed to rule out physical or psychological causes that could better account for the symptoms. Examples include hyperthyroidism, hearing loss, bipolar disorder, substance abuse, depression, and anxiety.
- Brain scans or brain imaging techniques (e.g., EEG, CT, or MRI) may be ordered to rule out brain abnormalities (that are inconsistent with ADHD), or brain trauma.
- Psychological and education testing (e.g., IQ tests and/or achievement tests) may be necessary to identify additional problems such as learning disability, intellectual disability, or other mental limitations.
Intelligence and Memory Testing
Intelligence and Memory testing are important parts of an ADHD evaluation. Although a diagnosis of ADHD can be made simply based on checklists and history, a more thorough assessment is performed to more clearly identify individual cognitive strengths and weaknesses. This detailed assessment further aids the development of a customized treatment plan.
Wechsler Adult Intelligence Scale (WAIS)
Intelligence tests measure peoples' mental abilities across many different areas. The WAIS is the most commonly used intelligence test for adults. The WAIS evaluates two primary areas of mental abilities: 1) Verbal Skills and, 2) Performance Skills. The verbal and performance skills sections each have several subtests. When the subtests scores are combined in each area, they form a single verbal score and a single performance score. When the verbal score and the performance scores are added together, you get a single number referred to as Intelligence Quotient or IQ for short. The average IQ score is 100.
The subtests scores help the clinician to identify patterns of relative strengths and weaknesses. Everyone excels in some areas, and not-so-well in others. This is very normal. However, a person's subtest pattern can be compared to the typical subtest scoring pattern of individuals with ADHD. For instance, we would expect to find that people with ADHD would have relative strengths in subtests that do not require concentrated effort; e.g., general information and vocabulary. Likewise, we would expect to find weaknesses in subtests that require sustained focus and concentration; e.g., mathematical computation and pattern recognition. The research supports these common-sense expectations. In fact, there is enough consistency among people with ADHD that these subtest patterns can be very helpful in the diagnostic process.
You will also recall that ADHD is characterized by a lack of achievement. The intelligence test also offers the clinician the opportunity to compare someone's mental abilities with their actual school or work performance. This comparison enables clinicians to detect if someone is underachieving, relative to their abilities. Of course, there can be many reasons for underachievement but it adds another clue to the diagnostic puzzle.
Wechsler Memory Scale, Third Edition (WMS-III)
The WMS-III is a battery of adult memory tests for ages 16 to 89 years. The test consists of 11 subtests (6 primary and 5 optional subtests). The primary subtests assess logical memory (memory for stories), verbal paired associates (memory for word pairs), letter-number sequencing, and various tasks related to visual memory. The optional subtests assess information and orientation; memory for lists of words and numbers; and other related memory tasks.