TORONTO – Impulsive-affective conduct disorder responds better to medication than does predatory conduct disorder, Dr. Robert Findling said at the joint annual meeting of the American Academy of Child and Adolescent Psychiatry and the Canadian Academy of Child and Adolescent Psychiatry.
“We need to do better by these children,” said Dr. Findling of Case Western Reserve University, Cleveland. “If you catch them early, before they are hardened by their behavior, you can help them. Young children with conduct disorder [CD] often say they know teachers and other kids think they are bad, and they don't want to be bad. No child deserves to live like that.”
Before deciding on a trial of medication, it's important to characterize the type of conduct disorder a patient presents. Both types are more prevalent in males and often comorbid with depression, anxiety, learning disabilities, or attention-deficit hyperactivity disorder (ADHD). Both types are associated with poor long-term outcomes. “This is a malignant condition. It's pervasive, pernicious, and associated with violence and high rates of antisocial behavior, incarceration, and substance abuse. This is not just a kid being dysfunctional,” he said.
Impulsive-affective CD involves reactive, unplanned, uncontrolled acts of aggression. The child may damage his own property or expose himself to physical harm. He loses control in front of other people and fights without purpose, often against someone stronger. He might express remorse after an explosion.
Predatory CD is a different matter, Dr. Findling said. “This is the kid who will beat somebody up for milk money. This person is quite different from the kid who explodes over a minor provocation.”
The aggressive acts are planned, controlled, and often concealed. The child is very careful to protect himself from harm in the incident and tries to plan it so that he profits in some way. Theft is often a motive. The child may say he is proud of his behavior.
Methylphenidate has been shown effective in CD, decreasing aggression scores significantly, compared with placebo (Arch. Gen. Psychiatry 1997;54:1073–80). Lithium has also been shown effective, “although it has never been embraced as a treatment due to the adverse events in this group,” Dr. Findling said. Those include nausea, vomiting, and urinary frequency.
In 2003, researchers concluded that divalproex was also effective. A 7-week study randomized children with CD to either low or high doses of the drug. The high dose (1,000 mg/day) was more effective in improving self-reported impulse control and self-restraint; almost 60% of those in the high-dose group were much or very much improved, compared with fewer than 10% of those in the low-dose group. Side effects were mild and transient (J. Clin. Psychiatry 2003;64:1183–91).
Many studies detail the benefits of risperidone (Risperdal), Dr. Findling said. A 2002 placebo-controlled trial concluded that a low dose of risperidone (1.16 mg/day) was significantly better than placebo in improving symptoms of CD in children with subaverage IQ and disruptive behavior disorder. Almost 80% of the active group was improved at the end of the trial.
“The magnitude of the dose is important here. This is lower than the dose prescribed by many U.S. providers,” he said. The most common side effects were mild, transient sedation and headache.
Two recent long-term trials of risperidone suggest that the benefit is durable, he said. An open-label trial of 107 children with CD concluded that the improvement was maintained on the same dose over 48 weeks (Am. J. Psychiatry 2004;161:677–84). A larger study, which looked at the effect in 504 children over 1 year, reached the same conclusion (J. Am. Acad. Child. Adolesc. Psychiatry 2005;44:64–72).
Risperidone is also effective in children who start on a psychostimulant but retain problematic aggression; it can be used effectively in children on a stimulant for ADHD. “The stimulant doesn't decrease the effectiveness of risperidone,” he said.
Some pilot studies suggest olanzapine (Zyprexa) and aripiprazole (Abilify) may have beneficial effects on aggression as well. A 2004 study examined olanzapine for aggression and tics in 10 children with Tourette's syndrome. The drug effectively reduced aggression and tic severity, and was well tolerated (J. Child. Adolesc. Psychopharmacol. 2004:14:255–66).
Dr. Findling studied aripiprazole specifically for its effectiveness in CD. “Over a very short time in a very aggressive group of people, we saw a very substantial response,” he said (Int. J. Neuropsychopharmacol. 2004;7:[suppl. 1]:S440).
Adverse events included dyspepsia and persistent emesis, which decreased when the dosing was adjusted. “We started out basing the dosage on weight-adjusted adult data and learned that this was not very well tolerated,” Dr. Findling said. “So we used a lower dose and got a better side effect profile.”