sufficient information to determine age at onset.
In childhood-onset conduct disorder, indivi duals are usually male, frequently display
physical aggression toward others, have disturbed peer rela tionships, may have had op-
positional defiant disorder during early ch ildhood, and usually have symptoms that meet
full criteria for conduct disord er prior to puberty. Many children with this subtype also
have concurrent attention-deficit/hyperactiv ity disorder (ADHD) or other neurodevel-
opmental difficulties. Individuals with childho od-onset type are more  likely to have per-
sistent conduct disorder into adulthood than are those with adolescent-onset type. As
compared with individuals with childhood-ons et type, individuals with adolescent-onset
conduct disorder are less likely to display a ggressive behaviors and tend to have more
normative peer relationships (although they often display conduct problems in the com-
pany of others). These individuals are less lik ely to have conduct disorder that persists into
adulthood. The ratio of males to  females with conduct disorder is more balanced for the
adolescent-onset type than for the childhood-onset type.
Specifiers
A minority of individuals with conduct disorder exhibit characteristics that qualify for the
“with limited prosocial emotions” specifier. The indicators of  this specifier are those that
have often been labeled as callous and unemot ional traits in research. Other personality
features, such as thrill seeking, fearlessness, and insensitivity to punishment, may also dis-
tinguish those with characteri stics described in the specifier. Individuals with character-
istics described in this specifier may be mo re likely than other individuals with conduct
disorder to engage in aggression that is planned for instrumental gain. Individuals with
conduct disorder of any subtype or any level of  severity can have characteristics that qual-