Clinical Summary
Clinical Summary: Presenting ADHD Symptoms, Subtypes, and Comorbid Disorders in Clinically Referred Adults With ADHD
Adults with attention-deficit/hyperactivity disorder often present with concentration and organization problems rather than overt hyperactivity, which can lead clinicians to miss the diagnosis. This article clarifies how ADHD actually presents in clinically referred adults and identifies which adult ADHD subtype carries a heavier psychiatric comorbidity burden.
Design
We assessed 107 adults with ADHD of both sexes (51% female; mean ± SD of 37 ± 10.4 years) using structured diagnostic interviews.
N
107 adults with ADHD
Population
Men and women between the ages of 18 and 55 years were eligible to become probands for the study.
Duration
The study was conducted from 1998 to 2003.
Key Findings
- Using current symptoms, 62% (n = 66) of adults had the combined subtype, 31% (n = 33) had the inattentive subtype, and 7% (n = 8) had the hyperactive/impulsive subtype.
- On the basis of DSM-IV criteria, 93% of adults with ADHD had either the predominately inattentive or combined subtypes.
- This was a highly comorbid group: 8% had no psychiatric comorbidity, 10% had a lifetime history of 1 comorbid psychiatric disorder, 14% had 2, 15% had 3, and 53% had 4 or more psychiatric comorbidities.
- ADHD-related impairment remained substantial: 40% (n = 43) endorsed severe impairment, 53% (n = 57) moderate impairment, and 7% (n = 7) mild impairment in the past; within the past month, 22% (n = 24) endorsed severe impairment, 50% (n = 54) moderate impairment, and 26% (n = 28) mild impairment.
- There were no differences between men and women in the total number of endorsed inattentive or hyperactive/impulsive symptoms, although females were significantly more likely to endorse the inattentive symptom of "loses things" (χ2 = 7.5, P < .01).
Clinical Bottom Line
In clinically referred adults with attention-deficit/hyperactivity disorder, inattention is the dominant presentation, and the combined subtype is the most common. Adults with combined ADHD warrant especially careful screening for psychiatric comorbidity.
Practice Implications
- When evaluating adults for attention-deficit/hyperactivity disorder, ask directly about inattentive symptoms such as distractibility, difficulty sustaining attention, and difficulty with sustained mental effort rather than relying on hyperactivity to signal the diagnosis.
- Use adult ADHD assessment as a trigger for broad psychiatric review, because only 8% had no psychiatric comorbidity and 53% had 4 or more psychiatric comorbidities.
- If an adult meets criteria for the combined subtype, look carefully for lifetime conduct disorder, bipolar disorder, and psychosis, since the combined subtype had significantly higher rates of these disorders than the inattentive subtype.
- Do not assume men and women present with different core ADHD symptom burdens in adulthood; total inattentive and hyperactive/impulsive symptom counts were similar, but comorbidity patterns differed by sex.
