How to Screen Psychiatric Comorbidity in Combined Adult ADHD
How should clinicians assess psychiatric comorbidity when an adult with ADHD appears to have the combined subtype?
Psychiatric comorbidity is common in adults with attention-deficit/hyperactivity disorder and can complicate clinical presentation. This guide applies when an adult ADHD evaluation identifies both inattentive and hyperactive or impulsive symptoms, since the combined subtype in this study had a heavier comorbidity burden than the inattentive subtype.
-
Identify whether the patient has the combined subtype
Determine subtype using the adult's current DSM-IV ADHD symptoms. This matters clinically because the combined subtype was the most common adult presentation in the sample and was associated with relatively more psychiatric comorbidity than the inattentive subtype.
-
Use the ADHD assessment as a trigger for broad comorbidity review
Do not stop the evaluation after confirming ADHD, because this was a highly comorbid sample. Only 8% had no psychiatric comorbidity, while 10% had 1 lifetime comorbid disorder, 14% had 2, 15% had 3, and 53% had 4 or more psychiatric comorbidities.
-
Screen especially for conduct disorder, bipolar disorder, and psychosis
If the adult has combined ADHD, look carefully for lifetime conduct disorder, bipolar disorder, and psychosis. Adults with the combined subtype had significantly higher rates of these disorders than adults with the inattentive subtype, and the article highlights these as the key subtype-linked comorbidities.
-
Consider sex-specific comorbidity patterns
Men and women had similar core ADHD symptom counts, but their comorbidity patterns differed. Men had higher lifetime rates of conduct disorder and alcohol abuse, whereas women had higher rates of dysthymia, panic disorder, agoraphobia, simple phobia, and generalized anxiety disorder.
-
Assess current functional impairment alongside comorbidity
Ask directly how much impairment ADHD symptoms are causing rather than inferring severity from symptom counts alone. In the past month, 22% of adults reported severe impairment, 50% moderate impairment, and 26% mild impairment related directly to ADHD symptoms.
Clinical Considerations
- Because the sample was largely clinically referred, the high comorbidity burden may not generalize to all adults with ADHD.
- The study could not disentangle whether comorbidity was linked to higher specific symptom clusters or whether comorbidity itself skewed symptom counts.
- The adults studied met 6 of 9 child-based ADHD diagnostic criteria, which may have selected for more severe and persistent presentations.
Bottom Line
Adults with combined ADHD warrant a particularly thorough psychiatric review, especially for lifetime conduct disorder, bipolar disorder, and psychosis.
