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Introduction
The essential feature of Conduct Disorder
is a repetitive and persistent pattern of behavior in which the basic
rights of others or major age-appropriate societal norms or rules
are violated. These behaviors fall into four main groupings: aggressive
conduct that causes or threatens physical harm to other people or
animals, nonaggressive conduct that causes property loss or damage,
deceitfulness or theft, and serious violations of rules.
Conduct Disorder may be diagnosed in individuals who
are older than age 18 years, but only if the criteria for Antisocial
Personality Disorder are not met. The behavior pattern is usually
present in a variety of settings such as home, school, or the community.
Because individuals with Conduct Disorder are likely to minimize their
conduct problems, the clinician often must rely on additional informants.
2. Epidemiology
The prevalence of Conduct Disorder
appears to have increased over the last decades and may be higher
in urban than in rural settings. Rates vary widely depending on the
nature of the population sampled and methods of ascertainment. General
population studies report rates ranging from less than 1% to more
than 10%. Prevalence rates are higher among males than females. Conduct
Disorder is one of the most frequently diagnosed conditions in outpatient
and inpatient mental health facilities for children.
3. Etiology
The onset of Conduct Disorder may
occur as early as the preschool years, but the first significant symptoms
usually emerge during the period from middle childhood through middle
adolescence. Oppositional Defiant Disorder is a common precursor to
the Childhood-Onset Type of Conduct Disorder. Onset is rare after
age 16 years. The course of Conduct Disorder is variable. In a majority
of individuals, the disorder remits by adulthood. Early onset predicts
a worse prognosis and an increased risk in adult life for Antisocial
Personality Disorder and Substance-Related Disorders. Individuals
with Conduct Disorder are at risk for later Mood Disorders, Anxiety
Disorders, Somatoform Disorders, and Substance-Related Disorders.
Estimates from twin and adoption studies show that Conduct Disorder
is influenced by both genetic and environmental factors. The risk
for Conduct Disorder is increased in children with a biological or
adoptive parent with Antisocial Personality Disorder or a sibling
with Conduct Disorder. The disorder also appears to be more common
in children of biological parents with Alcohol Dependence, Mood Disorders,
or Schizophrenia or biological parents who have a history of Attention-Deficit/Hyperactivity
Disorder or Conduct Disorder.
Subtypes:
Two subtypes of Conduct Disorder are provided based
on the age at onset of the disorder:
312.81 Childhood-Onset Type. This subtype is defined by the
onset of at least one criterion characteristic of Conduct Disorder
prior to age 10 years. Individuals with Childhood-Onset Type are usually
male, frequently display physical aggression toward others, have disturbed
peer relationships, may have had Oppositional Defiant Disorder during
early childhood, and usually have symptoms that meet full criteria
for Conduct Disorder prior to puberty. Many children with this subtype
also have concurrent Attention-Deficit/Hyperactivity Disorder. Individuals
with Childhood-Onset Type are more likely to have persistent Conduct
Disorder and to develop adult Antisocial Personality Disorder than
are those with Adolescent-Onset Type.
312.82 Adolescent-Onset Type. This subtype
is defined by the absence of any criteria characteristic of Conduct
Disorder prior to age 10 years. Compared with those with the Childhood-Onset
Type, these individuals are less likely to display aggressive behaviors
and tend to have more normative peer relationships (although they
often display conduct problems in the company of others). These individuals
are less likely to have persistent Conduct Disorder or to develop
adult Antisocial Personality Disorder. The ratio of males to females
with Conduct Disorder is lower for the Adolescent-Onset Type than
for the Childhood-Onset Type.
312.89 Unspecified Onset. This subtype is
used if the age at onset of Conduct Disorder is unknown.
4. References:
American Psychiatric Association: Diagnostic and Statistical
Manual of Mental Disorders, Fourth Edition, Text Revision. Washington,
DC, American Psychiatric Association, 2000.
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