Sepracor Inc. said on Wednesday that its recently approved Lunesta sleep drug appears to help fight insomnia and depression in patients with both disorders.

Preliminary results of a late-stage trial of 545 patients with both insomnia and major depression showed that those taking Lunesta and the antidepressant Prozac were less likely to see a worsening of their depression than those taking Prozac plus placebo.

The company said it appears that based on the preliminary results of the study, the combination of Lunesta and Prozac even improved symptoms of depression.

Patients treated with Lunesta also saw a statistically significant improvement in the time taken to get to sleep and in their ability to stay asleep.