The assessment of adults with ADHD is similar to that of children with the disorder. The process involves documenting current and past symptoms, establishing that the symptoms cause impairment, obtaining a developmental and psychiatric history, and performing a physical examination (). Several diagnostic evaluation forms for the assessment of ADHD in adults are available to help document all the necessary information.51
In accordance with DSM-IV criteria for ADHD1
(), the clinician must assess current symptoms (i.e., in the past 6 months) and those in childhood (i.e., before the age of 7 years). Obtaining a childhood history of ADHD is an essential component of the assessment. Self-report rating scales are available to help assess whether the ADHD symptoms were present to a significant degree in childhood.51,52,53
Patients may have poor insight or have difficulty accurately recalling their symptoms during childhood. Thus, in addition to gathering information from the patient, it may be useful to obtain school records and report cards as objective evidence of childhood onset of the disorder. For example, when examining school records it is useful to look for any comments written about the patient's attention (e.g., “daydreams,” “can't focus”), activity level (e.g., “always up from her desk,” “can't sit still”) and impulsive behaviour (e.g., “interrupts students when they're working,” “needs to learn to wait his turn or raise hand before answering”).
Current ADHD symptoms can be assessed using standardized rating scales.54
Scales for adults typically contain the 18 ADHD symptoms from the DSM-IV,1
each of which is rated on its frequency in the past 6 months using a 4-point scale, from 0 (never or not at all) to 3 (very often or very much). A patient is considered to meet the diagnostic criteria for ADHD–inattentive type if he or she has significant difficulty (a score of 2 or 3) for 6 or more of the 9 items on the list of inattentive symptoms. A patient is considered to have ADHD–combined type if he or she also has significant difficulty (a score of 2 or 3) for 6 or more of the 9 items on the list of hyperactive/ impulsive symptoms. It is relatively rare for adults to meet the criteria for ADHD–hyperactive/impulsive type, in which the patient meets the criteria for 6 or more of the hyperactive/impulsive symptoms without meeting the threshold for inattentive symptoms. Norms for adults have previously been published55
and provide clinicians with a benchmark against which to measure their patient's behaviour. Adults with ADHD may identify problems associated with ADHD (e.g., procrastination, lack of motivation, mood lability, low self-esteem) as their primary concern rather than the core symptoms. The Brown Attention-Deficit Disorder Scale56
is an instrument that can help identify areas of difficulty for the patient because it includes many of the problems encountered by adults with ADHD.
As with assessments of children with ADHD, when assessing adults it is beneficial to have one or more collateral informants complete the standardized rating scales. Ideally, there should be someone who knows the patient well enough to rate their current symptoms (e.g., spouse, close friend, parent, sibling) and someone who knew the person well enough as a child to rate their childhood behaviour (e.g., parent, aunt, uncle). The rationale for having a collateral informant stems from concerns about the reliability of patient self-reports about their ADHD symptoms. Some research suggests that adults with ADHD may either underreport57
or overreport symptoms.58
Recent studies have shown high correlations between self-reports and collateral reports of ADHD symptoms,59,60
which indicates that, if the clinician believes the patient has good insight, self-reports can be used on their own. Most ratings scales of adult ADHD have a version for the patient and one for the collateral informant.
Obtaining information about a patient's developmental history is important because it helps to establish that the symptoms were present in childhood and to rule out other psychiatric conditions (see ). The assessment of comorbid conditions and differential diagnoses can be difficult, but it is necessary because adults with ADHD have high rates of mood, anxiety, learning and personality disorders, and substance use and abuse.61,62
Comorbid conditions may require treatment in their own right, they may provide a relative contraindication to the use of stimulants, or they may alter the expected outcome of treatment. The management of ADHD with various comorbid conditions is beyond the scope of this review, but it has been addressed elsewhere.25,63
When in doubt, clinicians should consider consulting a psychiatrist who has expertise in this area.
The Adult Self-Report Inventory–4 and the Adult Inventory–4 (to be given to the collateral informant) are screening tools designed to assist clinicians with the assessment of comorbid conditions and differential diagnoses.64
These symptom inventories are particularly useful in this population because, in addition to the most common conditions in the DSM-IV, they include developmental disorders not often found in adult screening tools (e.g., Tourette's syndrome, Asperger's syndrome, learning problems, conduct disorder, oppositional defiant disorder) and problems that often accompany ADHD (e.g., temper outbursts, procrastination).
Because ADHD is highly familial, it is important to screen for a family psychiatric history of ADHD. In addition, the clinician needs to enquire whether first-degree relatives have had difficulty with tics, drug use and criminal behaviour, because these problems are not uncommon among adults with ADHD and may help identify risks for the patient being evaluated.
A physical examination should be conducted to rule out medical causes of the symptoms (e.g., neurological problems and thyroid abnormalities), to screen for problems that are often consequences of having ADHD (e.g., smoking, illicit drug use, fractures, poor nutrition, poor sleep hygiene), to identify contraindications to treatment with stimulant medication (e.g., hypertension, glaucoma) and to record the patient's baseline weight, which may change with treatment.
Electronic testing (e.g., continuous performance tests) and neuropsychological tests may contribute to the clinicians' overall impressions, but neither has good sensitivity or specificity on their own for diagnostic purposes.65
Psychoeducational testing is beneficial if the clinician suspects a learning disability.