- First of all. there is the problem that the very definition of what constitutes executive functions varies from one authority to another; there is no standard or accepted definition.
- When parents or teachers fill out checklists or ratings of executive functions, there appears to be agreement with standard definitions of ADHD (e.g. with DSM-IV clinical symptom definitions), but there is no relationship to executive functions as measured by actual cognitive functions measured in performance tests. (For instance, tests of working memory do not agree with ratings of memory performance.
- Impairment of executive functions is common in many disorders other than ADHD, for example anxiety, depression, psychosis, etc. In fact, executive dysfunction cuts across almost all mental disorders and cognitive impairments. It would thus appear to be more a consequence of disorders than a specific cause of disorders.
- Finally, a number of investigations fail to find the executive dysfunctions postulated for ADHD.
For these reasons I believe that while it is useful to assess executive functions in ADHD, particularly since these functions may be trainable and coachable, a full assessment of ADHD requires a much broader range of symptoms and diagnostic criteria.