Sustained-release lithium may be an effective treatment for pathological gambling in patients with bipolar spectrum disorder, also referred to as manic Depression, the results of a small study suggest.

Pathologic gambling is often associated with bipolar disorder, lead investigator Dr. Eric Hollander and colleagues note in their report, published in the American Journal of Psychiatry.

While other trials have suggested a beneficial effect of mood stabilizers in other impulse-control disorders, there have been no placebo-controlled studies of their use to treat compulsive gambling.

Hollander, a psychiatrist at Mount Sinai School of Medicine in New York, and his team enrolled 40 subjects who had been diagnosed with compulsive gambling and bipolar spectrum disorder; 29 patients completed the 10-week trial.

The 12 subjects randomly assigned to receive lithium were more likely to respond to treatment compared with the 17 assigned to receive a placebo, 83.3% versus 29.4%, respectively.

Gambling severity according to the Yale-Brown Obsessive Compulsive Scale total pathological gambling score averaged 8.3 in the treated patients and 17.0 in the placebo patients. Differences between the groups were statistically significant for the subscales measuring gambling thoughts/urges and gambling behavior, the authors note.

However, differences in self-reports of money lost, episodes per week and time spent per episode per week were not significantly different between the groups.

Mood instability ratings improved more in the lithium group, with scores on the Clinician-Administered Rating Scale for Mania Change of 6.58 in the lithium group versus 3.88 in the placebo group. The authors also observed a significant correlation between improvements in gambling and in mood stability.

“This study highlights the need to identify subgroups of pathological gambling patients with bipolar spectrum conditions because this may have important treatment implications,” Hollander and his associates conclude.

SOURCE: American Journal of Psychiatry, January 2005.