Structure and Diagnosis of Adult Attention-deficit/hyperactivity Disorder: Analysis of Expanded Symptom Criteria from the Adult ADHD Clinical Diagnostic Scale

Context: Controversy exists about the appropriate criteria for a diagnosis of adult attention-deficit/hyperactivity disorder (ADHD).

Objective: To examine the structure and symptoms most predictive of DSM-IV adult ADHD.

Design: The data are from clinical interviews in enriched subsamples of the National Comorbidity Survey Replication (n = 131) and a survey of a large managed health care plan (n = 214). The physician-administered Adult ADHD Clinical Diagnostic Scale (ACDS) was used to assess childhood ADHD and expanded symptoms of current adult ADHD. Analyses examined the stability of symptoms from childhood to adulthood, the structure of adult ADHD, and the adult symptoms most predictive of current clinical diagnoses.

Setting: The ACDS was administered telephonically by clinical research interviewers with extensive experience in the diagnosis and treatment of adult ADHD.

Participants: An enriched sample of community respondents.

Main Outcome Measure: Diagnoses of DSM-IV /ACDS adult ADHD.

Results: Almost half of the respondents (45.7%) who had childhood ADHD continued to meet the full DSM-IV criteria for current adult ADHD, with 94.9% of these patients having current attention-deficit disorder and 34.6% having current hyperactivity disorder. Adult persistence was much greater for inattention than for hyperactivity/impulsivity. Additional respondents met the full criteria for current adult ADHD despite not having met the full childhood criteria. A 3-factor structure of adult symptoms included executive functioning (EF), inattention/hyperactivity, and impulsivity. Stepwise logistic regression found EF problems to be the most consistent and discriminating predictors of adult DSM-IV /ACDS ADHD.

Conclusions: These findings document the greater persistence of inattentive than of hyperactive/impulsive childhood symptoms of ADHD in adulthood but also show that inattention is not specific to ADHD because it is strongly associated with other adult mental disorders. In comparison, EF problems are more specific and consistently important predictors of DSM-IV adult ADHD despite not being in the DSM-IV, suggesting that the number of EF symptoms should be increased in the DSM-V/ICD-11.