This research examines 75 children, previously diagnosed with attention deficit/ hyperactivity disorders (AD/HD), referred to a multidisciplinary medical setting because of unsatisfactory response to medical or educational interventions. Systematic descriptive data from parents and teachers have been compared with the 14 symptoms characterizing the AD/HD syndrome in the DSM-III-R (APA, 1987). The initial reasons for referral have been reexamined using an extended list of diagnostic descriptors, and nearly one-third of this study's diagnosed AD/HD group has been reclassified with mental disorders. The comorbidity among AD/HD symptoms, other mental disorders, and information-processing deficits (learning disabilities) has rendered 8 of the 14 AD/HD symptoms useless in accurately describing the presenting behaviors. An extended list of emotional and inforrnation-processing behavioral descriptors seems necessary if a meaningful diagnosis of AD/HD is to be achieved. Diagnostic considerations are discussed, and AD/HD as a single entity using the 14 DSM-III-R (APA, 1987) behavioral descriptors is critically challenged. The data support the changes in DSM-IV (APA, 1994), which differentiate predominately inattentive type from hyperactive-impulsive type disorders, while altering and adding several new behavioral descriptors. Further differentiation is now needed among behaviors isolated and specific to AD/HD, isolated and specific to other developmental or mental disorders, and comorbid and generalized across conditions. The diagnosis of attention deficit/hyperactivity disorders (AD/HD) requires identifying 8 of 14 behavioral symptoms comprising the AD/HD syndrome. Limited theoretical explanations exist as to the relationship between the presenting, observable behaviors and the 14 symptoms that comprise this syndrome. Schaughency and Hynd (1989) have provided a neuropsychological explanation of the relationship between impulse control and specific behaviors with differentiated subtypes of AD/HD based on neurological structures and biochemical systems such as deficiencies in neurotransmitter systems. The importance of this neuropsychological model is that it focuses on attention control mechanisms within the central nervous system; thus, children presenting AD/HD symptoms may be prone to a wide range of problematic behaviors, includirlg those associated with other mental and developmental disorders.The two behaviors most commonly observed clinically in AD/HD children are hyperactivity and attention deficits. Lahey and Carlson (1991) have reviewed the research and report two distinct populations, one with primarily inattention and behavioral disorganization and the other with motor hyperactivity and impulsive behaviors. They conclude that AD/HD children displaying primarily hyperactivity and impulsive behaviors often have serious conduct disorders, whereas children with attention deficits more likely display anxiety, depression, and shyness.In another study attempting to isolate behaviors distinguishing between subpopula...