ADHD can be reliably diagnosed in children, adolescents, and adults 28
. Using the current guidelines, the child or adult patient must meet the criteria in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR)29
. It is important to note, however, that the DSM-IV-TR criteria for ADHD symptoms were derived from youth to age 17 years and therefore were not specifically tailored to adults and hence, may not always “fit” adults with the disorder 28, 30
. The symptoms of the disorder are categorized as follows: inattention-difficulty sustaining attention and mental effort, forgetfulness, and distractibility; hyperactivity-fidgeting, excessive talking, and restlessness; and impulsivity-difficulty waiting one’s turn and frequent interruption of others. The DSM-IV-TR
criteria also include onset by age 7, impaired functioning in at least 2 settings (home, work, school, job), and more than 6 months of duration 30
. Three subtypes of the syndrome are currently recognized: predominantly inattentive, predominantly hyperactive-impulsive, and the combined type, which is the most common and typically more severe and with more comorbidity 29, 31, 32
. Between 90 to 95% of adolescents and adults with ADHD manifest the inattention cluster of symptoms at least as a component of their disorder 31
. Of interest, the combined subtype of ADHD may simply represent a more severe and debilitating presentation of ADHD (e.g. more symptoms) and there may be relatively more stability of the subtype with development 32, 33
To meet the diagnostic criteria for the inattentive or hyperactive-impulsive subtypes, an individual must have 6 or more of the 9 symptoms from either group of criteria (18 possible traits in all) 30
. For the combined subtype, an individual must have 6 or more inattentive symptoms and 6 or more hyperactive-impulsive symptoms. To warrant the ADHD diagnosis, symptoms must cause significant impairment. Adults diagnosed with the disorder must have had childhood onset and persistent and current symptoms, although allowance is made for incomplete persistence of full criteria (ADHD-in partial remission) or lack of clear childhood symptoms (ADHD NOS).
Of interest, whereas clinicians are concerned as to the possibility of purposely misrepresenting or over-reporting of ADHD symptoms by college students or adults, data suggest the opposite may be operant. Mannuzza et al. 34
in a prospective 16-year follow-up of children with ADHD now at a mean age of 25, found that of the 176 individuals with a well characterized past history of ADHD, only 28% of the adults through direct interviews were identified as having childhood ADHD. These data further highlight issues around the relatively poor sensitivity of recalling symptoms (and establishing the diagnosis of ADHD) by adult self-report, particularly when not anchoring symptoms in childhood.
The diagnosis of ADHD is made clinically with scales used in an ancillary manner. The patient’s symptoms, severity of impairment, possible comorbidity, family history, and psychosocial stressors may be determined during the patient and/or parent interview. In pediatric evaluations, the adolescent’s behavior and parent-child interaction are observed, and the child’s school, medical, and neurological status are evaluated 2
. A number of diagnostic and follow-up scales are available (see www.schoolpsychiatry.org
. Symptom scales used with all age groups (to assess home, school, and job performance) include, but are not limited to, the ADHD Symptom Checklist, SNAP-IV Teacher and Parent Rating Scale, Conners Rating Scales-Revised,, Brown Attention-Deficit Disorder Scales for Children, and the ADHD Symptoms Rating Scale 36
. Although these tools quantify behavior deviating from norms, they should not be used alone to make or refute the diagnosis.
Diagnosing adults involves careful querying for developmentally appropriate criteria from the DSM-IV-TR
concerning the childhood onset, persistence, and current presence of symptoms 29
. Diagnostic aids are available for adult ADHD 36,37
. For instance, the Adult Self Report Scale, Conners Adult ADHD Scales, and Brown Attention scales for adults are among instruments available to assist in the diagnosis of ADHD36,37
. For a briefer screening of adults, the World Health Organization Adult ADHD self-report scale () can be downloaded (www.who.org
) and has been validated as a manner of identifying those at risk for ADHD who necessitate further screening 38
Follow-up studies show that prominent symptoms and impairment related to the disorder persist into adulthood in approximately one-half of cases 39, 40
. There appears to be developmental variance in the ADHD symptom profile across the life span 31, 32, 39-41
. Longitudinally derived data in ADHD youth growing up indicate that the symptom cluster of hyperactivity and impulsivity decays over time, while the symptoms of inattention largely persist 32, 39-41,31
. In support of this notion, data derived from a group of clinically referred adults with ADHD indicate that approximately half of adults endorse clinically significant levels of hyperactivity/impulsivity, but 90% endorse prominent attentional symptoms 32,31
A substantial body of literature implicates abnormalities of brain structure and function in the pathophysiology of both childhood and adult ADHD 42-48,49-51
. We have known for decades that ADHD youth show impaired performance on tasks assessing vigilance, motoric inhibition, organization, planning, complex problem solving, and verbal learning and memory 52, 53
. Prominent neuropsychologically-derived executive dysfunction is associated with learning disabilities and poorer overall prognosis over time in ADHD youth 54
. Similar findings are emerging in adults with ADHD 52
. While neuropsychological testing is not used clinically to diagnose ADHD in adults, such testing aids in identifying learning disabilities, sub average intelligence, and specific information processing deficits.