Pitfalls in the Diagnosis of Adult ADHD

The diagnosis of attention-deficit/hyperactivity disorder in adults poses a challenge for patients and clinicians alike.  Hyperactivity is a less prominent sign in adults with ADHD than in children.  Attention problems may be due to a variety of conditions.  A common mistake is for a diagnosis of ADHD to be made based on a scale assessing attention problems.   This is an inappropriate diagnostic strategy unless attention symptoms can be liked specifically to an ADHD and not some other psychiatric or neurological disorder.

Kessler and colleagues recently published a study examining the current DSM-IV diagnostic criteria.  They used a sample of subjects from the National Comorbidity Survey Replication and a sample of patients from a large health plan.  The goals of the study were:

• Examine the stability of childhood ADHD symptoms to adulthood
• Examine the structure of ADHD symptoms in adults
• Find the adult symptoms most predictive of a current adult ADHD symptoms

The study found approximately 45-50% of those who met childhood ADHD diagnostic criteria met criteria as an adult.  The exact rates depended on the subtype of diagnosis in childhood, i.e. attention only, hyperactivity only, or both attention and hyperactivity.  Persistence was higher for those that met attention or attention and hyperactive subtypes as a child.

The research team found that adults with ADHD specifically endorsed ADHD symptoms tapping into brain executive function, i.e.

• “makes careless mistakes”
• “difficulty organizing tasks”
• “loses things”

The frontal lobe is the primary brain region involved in executive function and other symptoms of executive (and frontal lobe dysfunction) are available.   Kessler and colleagues recommend additional symptoms of executive function should be queried and possibly added to future versions of DSM diagnostic criteria for ADHD. These additional symptoms of executive dysfunction include problems with:

• planning
• prioritizing
• multitasking
• remembering details
• meeting deadlines
• maintaining self-discipline

Some of my own research has addressed the issue of diagnostic prevalence of ADHD in clinical populations.  We examined a series of women with eating disorders and looked for the presence of ADHD.  If just adult ADHD symptoms were assessed 21% of the sample would have been diagnosed with ADHD.  But since ADHD begins in childhood and requires childhood symptoms, we looked for presence of childhood symptoms to confirm the adult diagnosis of ADHD.  Only 5.8% of subjects had both childhood and adult symptoms.  This prevalence estimate did not appear distinctly different than the general population.

So it is important to have a comprehensive assessment when looking for the diagnosis of adult ADHD.  Executive deficits in adult ADHD appear to be a key symptom but are not adequately addressed in a DSM-IV ADHD  diagnostic assessment.

Animation of frontal lobe in red from the Wikipedia Commons file: BodyParts 3D authored by Life Sciences Data Base (LSDB).

Kessler RC, Green JG, Adler LA, Barkley RA, Chatterji S, Faraone SV, Finkelman M, Greenhill LL, Gruber MJ, Jewell M, Russo LJ, Sampson NA, & Van Brunt DL (2010). Structure and diagnosis of adult attention-deficit/hyperactivity disorder: analysis of expanded symptom criteria from the adult ADHD clinical diagnostic scale. Archives of general psychiatry, 67 (11), 1168-78 PMID: 21041618


Yates WR, Lund BC, Johnson C, Mitchell J, & McKee P (2009). Attention-deficit hyperactivity symptoms and disorder in eating disorder inpatients. The International journal of eating disorders, 42 (4), 375-8 PMID: 19040267