6 Challenges in Assessing ADHD in Adult Patients

Because ADHD is considered a developmental disorder, the presence of current symptoms as well as a history of previous symptoms (in childhood) needs to be established. Even with DSM-5 criteria, practitioners need to make a retrospective evaluation of the presence of ADHD in childhood in order to establish a diagnosis in adulthood but many patients have problems recalling childhood symptoms or they have no documentation substantiating a childhood diagnosis. Patients with ADHD also have impaired short- and long-term memory; therefore, recall bias can affect the accuracy of assessments. The challenge is determining whether this was an established childhood diagnosis, a missed diagnosis in childhood, or a late-onset adult ADHD.

Determining whether ADHD is present alone or whether it is comorbid with another psychiatric disorder is critical-a mood or anxiety disorder may be responsible for the ADHD-like symptoms. Compared with patients who have a depressive disorder, those with ADHD tend to have more occupational or functional impairment, organizational deficits, and impulsivity issues. The distinction between ADHD and bipolar disorder can be especially challenging, since the manic and hypomanic features of bipolar disorder are similar to the hyperactive and impulsive symptoms associated with ADHD. In patients with ADHD, these symptoms tend to be constant, but in bipolar disorder there is a waxing and waning of manic symptoms interrupted with periods of depression. Patients with bipolar disorder tend to be goal-directed and are usually productive, while patients with ADHD are less able to complete tasks. Substance use disorders are also common in patients with ADHD.

Patients who are highly functioning with higher than average IQs tend to develop useful coping mechanisms to overcome symptoms or to hide them from others. Some patients become compulsive list makers or develop a highly structured daily routine in order to complete tasks and to minimize forgetting details or losing belongings. They may unknowingly rely on coworkers or family members to an inappropriate extent for reminders or assistance in completing tasks or fulfilling responsibilities. Although compensatory mechanisms are generally therapeutic for the patient, they may cloud the clinical picture particularly in cases where the patient does not self-suspect ADHD but rather a family member or the practitioner suspects ADHD.

Among the DSM criteria is an item that evaluates the degree of clinical impact of ADHD symptoms on life domains. For a diagnosis of ADHD, there must be clear evidence of significant clinical impact, which can be especially difficult to objectively assess. Failure to demonstrate significant clinical impact precludes a diagnosis of ADHD even if all other criteria are satisfied. Examples of true clinical impact include disciplinary action at work, risk of job loss, relationship discord, or frequent automobile accidents or accidents in the home.

Given the high degree of psychiatric symptom overlap, the realistic possibility of feigning ADHD symptoms, and a general fear of enabling drug addiction or diversion, the underdiagnosis versus overdiagnosis of ADHD in practice has been called into question. There are no available data to quantify this concern, and therefore no support can be lent to the argument of failure to recognize ADHD or misdiagnosis of ADHD. A psychiatric comorbidity and the point of entry into the health care system (primary care versus a psychiatrist) may influence whether ADHD is overdiagnosed or underdiagnosed.