Diagnosing adult attention deficit hyperactivity disorder: are late onset and subthreshold diagnoses valid?
OBJECTIVE
Diagnosing attention deficit hyperactivity disorder (ADHD) in adults is difficult when diagnosticians cannot establish an onset before the DSM-IV criterion of age 7 or if the number of symptoms recalled does not achieve DSM's diagnosis threshold.


METHODS
The authors addressed the validity of DSM-IV's age-at-onset and symptom threshold criteria by comparing four groups of adults: 127 subjects with full ADHD who met all DSM-IV criteria for childhood-onset ADHD, 79 subjects with late-onset ADHD who met all criteria except the age-at-onset criterion, 41 subjects with subthreshold ADHD who did not meet full symptom criteria for ADHD, and 123 subjects without ADHD who did not meet any criteria. The authors hypothesized that subjects with late-onset and subthreshold ADHD would show patterns of psychiatric comorbidity, functional impairment, and familial transmission similar to those seen in subjects with full ADHD.


RESULTS
Subjects with late-onset and full ADHD had similar patterns of psychiatric comorbidity, functional impairment, and familial transmission. Most children with late onset of ADHD (83%) were younger than 12. Subthreshold ADHD was milder and showed a different pattern of familial transmission than the other forms of ADHD.


CONCLUSIONS
The data about the clinical features of probands and the pattern of transmission of ADHD among relatives found little evidence for the validity of subthreshold ADHD among such subjects, who reported a lifetime history of some symptoms that never met DSM-IV's threshold for diagnosis. In contrast, the results suggested that late-onset adult ADHD is valid and that DSM-IV's age-at-onset criterion is too stringent.
Faraone
Stephen V
SV
Department of Psychiatry and Behavioral Sciences, SUNY Upstate Medical University, 750 East Adams St., Syracuse, NY 13210, USA. faraones@upstate.edu
Biederman
Joseph
J
Spencer
Thomas
T
Mick
Eric
E
Murray
Kate
K
Petty
Carter
C
Adamson
Joel J
JJ
Monuteaux
Michael C
MC
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D001289:Attention Deficit Disorder with Hyperactivity / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D002648:Child; D016241:Child of Impaired Parents / Q000523:psychology / Q000706:statistics & numerical data; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011594:Psychometrics; D015203:Reproducibility of Results; D012189:Retrospective Studies