Objective: Current diagnostic criteria for ADHD require the consideration of impairment in making a diagnosis, although clinical and research definitions of ADHD rely more heavily on reported symptoms. This study explored the relationship between impairment and symptoms, variables predictive of impairment, and variation in ADHD identification when impairment criteria are added to symptom criteria.
Method: ADHD symptoms and impairment were assessed using archival parent and teacher rating scale data.
Results: The results indicated that (a) single impairment measures alone and a global impairment index were, at best, only moderately correlated with symptom reports; (b) predictor variables accounted for a small percentage of the variance in impairment; and (c) the number of children meeting criteria for ADHD diagnosis varied dramatically when impairment measures were considered.
Conclusion: Symptoms and impairment are related yet distinct constructs that should be measured independently to determine the presence of ADHD.