Better control of aggression

Children with disruptive behavior disorders (DBD) constitute a heterogeneous
group in terms of characteristics, presumed underlying dysfunctions, and type
of aggression displayed. Some DBD children show relatively high levels of
callous-unemotional traits (CU), presumably because of an underlying empathy
deficit, and display increases in reactive as well as instrumental aggression.
However, others show low levels of CU traits; instead they have problems in
self-regulation and display primarily reactive aggression. Research into the
underlying processes of antisocial and aggressive behavior at the level of
cognition and neurobiology may increase theoretical understanding and provide
important information for prevention and intervention strategies. Therefore,
part of the proposed study entails studying cognition and neurobiology in
children with DBD in addition to their behavior.
This study will also evaluate factors that influence the effectiveness of
Parent Management Training Oregon (PMTO). Previous research has shown that PMTO
effectively reduces disruptive behavior by teaching parents more effective ways
of parenting. In addition, research has investigated variables in the parents*
background that moderate the trainings* effectiveness. However, given that
children with DBD are a heterogeneous group, a change in parents* behavior
might be more effective in targeting some causes of problem behavior than
others. In order to identify the causes of disruptive behavior that are
effectively targeted by PMTO, the inclusion of cognitive and neurobiological
measures in the proposed study may be of great value.

This study has two main objectives. The first objective is to investigate
whether children with DBD, when compared to low aggressive and antisocial
control children, have neuropsychological and neurobiological abnormalities
that may underlie their antisocial and aggressive problem behavior.
Specifically we will look at empathic and self- regulation dysfunctions in
relation to (types of) aggression and callous-unemotional (CU) traits. A second
objective of this study is to investigate the usefulness of this knowledge of
the neuropsychological and neurobiological impairments in children with DBD in
predicting treatment outcome. We hypothesize that a) PMTO will be effective in
decreasing levels of aggression and antisocial behavior in DBD children, b) for
children with higher levels of callous-unemotional (CU) traits (and presumed
underlying empathy deficits with fear and sadness) PMTO is less effective, as
it is known that antisocial behavior in these children is under the influence
of social environmental factors too a lesser extent than in children with lower
levels of CU traits and c) for children characterized primarily by
self-regulation deficits and reactive aggression PMTO is more effective, as
self-regulation skills are expected to improve by PMTO. Therefore, we
hypothesize that biomarkers (i.e. neuropsychological and neurobiological
variables) that are presumably underlying factors in the etiology of different
types of aggressive behaviors and CU traits in DBD children are predictive of
treatment effectiveness of PMTO.

Randomized controlled trial, Longitudinal study

Parents of DBD children recruited from the clinical centres will all receive
PMTO treatment. One in three parents of the DBD children recruited from special
education schools and regular primary schools will receive PMTO treatment. The
other parents of DBD children will receive care as usual. The control group,
recruited at regular primary schools, will also receive care as usual.

There are no risks associated with the proposed study. The burden for the
children, parents and teachers is kept at a minimal level. The requested time
investment for the children is a total of approximately11 hours (distributed
over 3 visits), for the parents approximately 4 hours (distributed over 1 visit
and 2 phone calls) and for the teachers approximately 1.5 hours (distributed
over 3 phone calls). The collection of saliva and physiological measures will
pose no significant burden to children: these will not cause discomfort or
pain. There will be no clinical diagnostic assessments in this study. If
parents wish clinical diagnostic assessment (medical, psychological), we will
refer them to clinicians.