The mood stabilizer divalproex sodium (Depakote) may be useful in controlling the explosive tempers and labile moods often associated with conduct disorder and oppositional defiant disorder in teenagers, according to a new study that confirms earlier findings.

The study, by Stephen J. Donovan, M.D., a clinical professor in the department of therapeutics at the New York State Psychiatric Institute’s Division of Epidemiology of Brain Disorders, compared divalproex with placebo in a double- blind, crossover study.

Twenty patients aged 10 to 18 who were being treated on an outpatient basis were randomly assigned to one of two groups for the study. Each of the subjects met criteria for a chronic behavioral conduct disorder and met additional criteria for explosive temper and mood lability.

The first group received six weeks of divalproex therapy followed by six weeks of placebo therapy. The second group received placebo during the initial six weeks, followed by six weeks of divalproex therapy. Neither the subjects nor the investigators knew to which group each individual was assigned. All subjects were evaluated at the end of each phase.

At the end of the first six weeks of the trial, eight of the 10 subjects receiving divalproex had "responded" to the drug, according to a report in the May American Journal of Psychiatry. A "response" was defined by the investigators as the subject showing a substantial (greater than or equal to 70 percent) reduction from baseline in scores on two standardized measurements, the Modified Overt Aggression Scale and the anger-hostility subscale of the SCL-90. None of the patients who received placebo during the first six weeks responded to the treatment.

Fifteen of the 20 original subjects continued into the second six-week phase of the trial. At the end of the 12 weeks, 12 of the 15 met the response criteria only during the divalproex phase, one during the placebo phase, one during both phases, and one subject never met response criteria.

Although the number of study subjects was small, the investigators concluded that the very strong, statistically significant response to divalproex deserves further study in patients with known conduct disorders.

Divalproex, originally approved as an anticonvulsant, was approved as a mood stabilizer for controlling mania in 1996. Mood stabilizers have shown antimanic and antiaggressive properties in other study populations. The present study may help to further development of standardized pharmacological treatment for patients with conduct disorders, a population that as yet has no standardized treatment.