interpersonal style may identify a subtype of child-
hood-onset CD. More important, the presence of cal-
lous-unemotional traits may provide the necessary
developmental link between CD and psychopathy.
Cross-sectional studies have found that antisocial
youths with callous-unemotional traits exhibit a
greater number, variety, and severity of conduct prob-
lems and more severe forms of aggression. Children
with CD and callous-unemotional traits also evidence
a preference for thrill-seeking activities, possess a
reward-dominant response style, and demonstrate less
anxiety. Further support for this distinction is the find-
ing that genetic factors appear to play a larger role in
those with callous-unemotional traits. Finally, cal-
lous-unemotional traits are predictive of a number of
negative outcomes, including a greater number and
variety of conduct problems, higher levels of proac-
tive aggression and self-reported delinquency, more
police contacts, and a diagnosis of APD in adulthood.Prevention and Intervention
CD is typically regarded as a disorder that is not very
amenable to treatment efforts. In fact, earlier research
suggested that the majority of early treatment efforts
have been found to be largely ineffective. Second,
treatment of CD is difficult owing to noncompliance.
Finally, certain interventions, such as peer group
strategies, can have iatrogenic effects and increase the
level and severity of antisocial behavior. Despite these
generally negative early findings with respect to the
treatment of CD, a number of interventions have been
found to be effective, including medication and vari-
ous psychosocial treatments.
For very severe cases of CD, some have suggested
that psychopharmacology may be indicated. Jeffrey
Burke and colleagues suggest that drugs such as
lithium, risperidone, and methylphenidate may be
effective for youths with severe CD. More specifi-
cally, LeAdelle Phelps and colleagues suggest that
haloperidol, clonidine, methylphenidate, and risperi-
done may be effective in reducing severe aggression
in youths with CD. However, psychopharmacology is
not recommended as the primary treatment for CD
because there is a lack of evidence that medication can
alter the symptoms of CD per se and the medications
do not have a prophylactic effect on CD symptoms.
Rather, it appears that medication is most effective in
reducing severe conduct problems in difficult cases.
Although we note these recommendations for severe
CD, we do so with caution given the lack of soundmethodological studies on the effectiveness of psy-
chopharmacological treatments for youths with CD.
Mental health professionals should carefully weigh
the costs and benefits of administering drugs in the
treatment of CD.
A number of effective behavioral and psychosocial
interventions for treating CD have been reviewed by
Alan Kazdin and Paul Frick. One of the most effective
interventions is parent management training (PMT).
The focus of PMT is to reduce problem behaviors and
increase prosocial behaviors by educating parents in
techniques such as positive reinforcement, consistent
discipline, and effective supervision. There is evi-
dence suggesting that PMT is effective in the short
term in clinical populations, reduces deviant behavior
across multiple domains, and is able to reduce prob-
lematic behaviors to within the levels of normative
youth, with benefits evident 1 to 3 years after treat-
ment. Similarly, intervention strategies that use appro-
priate parenting strategies and attachment principles
have also proved effective in terms of decreasing
externalizing and internalizing problems in adoles-
cents with CD. However, it can be difficult to motivate
parents to complete treatment programs, and there is
evidence that parent training is not always effective
with severely dysfunctional families.
Another effective treatment strategy adopts a cog-
nitive-behavioral approach, which targets deficits in
social cognition and problem solving, largely through
inhibiting impulsive or angry responding by altering
the processing of social information. A variant of this
approach is child social skills training, which focuses
on addressing interpersonal problems through tech-
niques such as anger control and coping skills. There
is some evidence for the effectiveness of social skills
training in terms of decreases in aggression and anti-
social behavior, increases in prosocial behavior in the
short term, and improved interactions with peers.
However, it can be difficult to maintain the skills over
long periods and in domains outside the therapeutic
setting. Therefore, some researchers recommend
booster sessions to maintain the effects of treatment.
A promising approach is that of multimodal inter-
ventions such as multisystemic therapy (MST), which
addresses risk at the individual, family, peer, school,
and neighborhood levels. MST involves a comprehen-
sive assessment to determine how the various levels
influence the youth’s problem behavior, and this
information is then used to develop an individualized,
intensive treatment plan. For example, parents may be
educated in how to improve communication, andConduct Disorder——— 135C-Cutler (Encyc)-45463.qxd 11/18/2007 12:41 PM Page 135