Attention Deficit Hyperactivity Disorder: Diagnosis [Clinical Review]

Attention deficit-hyperactivity disorder (ADHD) has been defined as "the inability to marshal and sustain attention, modulate activity level and moderate impulsive actions" (1). A commonly used diagnostic protocol for the primary care physician is the American Academy of Pediatrics (AAP) "Clinical Practice Guideline: Diagnosis and Evaluation of the Child With Attention-Deficit/Hyperactivity Disorder" (2). This guideline includes the following 6 recommendations:

RECOMMENDATION 1: In a child 6 to 12 years old who presents with inattention, hyperactivity, impulsivity, academic underachievement, or behavior problems, primary care clinicians should initiate an evaluation for ADHD.
 
RECOMMENDATION 2: The diagnosis of ADHD requires that a child meet the Diagnostic and Statistical Manual of Mental health Disorders, Fourth Edition (DSM-IV) criteria.
 
RECOMMENDATION 3: The assessment of ADHD requires evidence directly obtained from parents or caregivers regarding the core symptoms of ADHD in various settings, the age of onset, duration of symptoms, and degree of functional impairment.
 
RECOMMENDATION 4: The assessment of ADHD requires evidence directly obtained from the classroom teacher (or other school professional) regarding the core symptoms of ADHD, the duration of symptoms, the degree of functional impairment, and coexisting conditions. A physician should review any reports from a school-based multidisciplinary evaluation where they exist, which will include assessments from the teacher or other school-based professionals.
 
RECOMMENDATION 4A: Use of these scales is a clinical option when diagnosing children for ADHD.
 
RECOMMENDATION 4B: Use of teacher global questionnaires and rating scales is not recommended in the diagnosing of children for ADHD, although they may be useful for other purposes.
 
RECOMMENDATION 5: Evaluation of the child with ADHD should include assessment for coexisting conditions.
 
RECOMMENDATION 6: Other diagnostic tests are not routinely indicated to establish the diagnosis of ADHD.

While the above recommendations appear to be straight forward there are other complexities which confront the practitioner attending a child he/she suspects has ADHD. The DSM-IV requires all the following for a diagnosis of ADHD (3):

1) An evaluation of 18 behavioral symptoms and finding 6 of 9 present in the hyperactive/impulsive domain and/or 6 of 9 present in the inattentive domain persisting for 6 months.
 
2) Onset of symptoms before age 7.
 
3) Clear evidence of functional impairment in two settings or more.
 
4) No other explanation for the symptomology.
 
The specific criteria of the DSM-IV

Diagnostic difficulties become more apparent when one considers there are three subtypes of ADHD. They are predominately hyperactive-impulsive, predominately inattentive type and combined type (4). Additionally comorbidities abound with up to 50% of the inattentive subtype also experiencing anxiety and depression and 80% of the combined subtype experiencing oppositional defiant disorder/conduct disorder (5).

Another complexity of the diagnostic process in ADHD is the different diagnostic challenges facing the physician when evaluating a preschool child as opposed to the school aged child, adolescent or adult.

Implementation of the AAP guidelines and use of the DSM-IV criteria have been less than successful. In a national survey sample of 861 primary care physicians only 28% used the DSM-IV criteria (6). A separate study showed only 4% of clinicians and nurse practitioners used all of the AAP diagnostic guidelines (7).

Considering the complexities of diagnosis and the impact on the life of the ADHD patient, unless the physician is well trained, current with the literature and experienced in using the diagnostic protocols of ADHD, a referral to a mental health specialist may be the best diagnostic option.