Abnormal Psychology

Childhood Disorders 655

example, people with attention-defi cit/hyperactivity disorder may, as a result of

their impulsivity or hyperactivity, annoy other people or ignore a request to “calm

down” or “sit down.” However, in this context, the behaviors are not expressing

defi ance but are a result of attention-defi cit/hyperactivity disorder.

Sometimes, disruptive behaviors arise as a response to still other disorders or

problems, and this possibility should be kept in mind by a clinician. For instance,

a child who is having diffi culties with schoolwork, perhaps because of dyslexia or

another learning disorder, may act up, or be defi ant in an effort to hide the problem

by distracting the teacher and classmates.

What Is Attention-Defi cit/Hyperactivity Disorder?

Individuals who have oppositional defi ant disorder or conduct disorder behave

disruptively because they want to defy rules, authority fi gures, or social norms.

Those who have a third type of disorder, attention-defi cit/hyperactivity disorder,

often behave disruptively but do so unintentionally. People with attention-defi cit/

hyperactivity disorder are unusually impulsive and/or are hyperactive, which is

why they have diffi culty conforming to rules and social norms that call for re-

straint or calm behavior.

Attention-defi cit/hyperactivity disorder (ADHD) is characterized by inatten-

tion, hyperactivity, and/or impulsivity. People diagnosed with this disorder vary in

which set of symptoms is most dominant; some primarily have diffi culty maintaining

Attention-defi cit/hyperactivity disorder

(ADHD)

A psychological disorder that typically

arises in childhood and is characterized by

inattention, hyperactivity, and/or impulsivity.

Prevalence

• Estimates of prevalence rates for this disorder vary widely, from 2% to 16%, depending on the
  specifi c population investigated and the specifi c research methods used.
  Onset


• Symptoms usually emerge before 8 years of age, although they may become evident as late as 13.


• Symptoms are typically observed at home before occurring in other contexts.


• The onset progresses gradually, over months or even years, until the symptoms reach the point
  where the diagnostic criteria are met.
  Comorbidity


• Attention-defi cit/hyperactivity disorder is the most common comorbid disorder (Costello et al.,
  2003; Lahey, McBurnett, & Loeber, 2000); up to 90% of children with oppositional defi ant dis-
  order also exhibit symptoms of attention-defi cit/hyperactivity disorder (Frick & Muñoz, 2006).


• Learning disorders may also co-occur with oppositional defi ant disorder.
  Course


• Most people with the childhood-onset type of conduct disorder were previously diagnosed
  with oppositional defi ant disorder (Whittinger et al., 2007); however, most people with opposi-
  tional defi ant disorder do not go on to develop conduct disorder.
  Gender Differences


• Before puberty, more males than females are diagnosed with oppositional defi ant disorder.
  After puberty there is no sex difference in prevalence.


• Males exhibit more persistent and more confrontational symptoms than females do.
  Cultural Differences


• Different cultures may have different norms concerning what defi ant behaviors are considered
  inappropriate or unacceptable.

Source: Unless otherwise noted, the source for information is American Psychiatric Association, 2000.

Table 14.13 • Oppositional Defi ant Disorder Facts at a Glance