Zolpidem extended-release tablets improve both insomnia and quality of daily functioning in patients with comorbid major depressive disorder, according to a presentation at the annual meeting of the Associated Professional Sleep Societies.

The current study, an eight-week trial, randomized patients with comorbid insomnia and major depressive disorder to 12.5 mg or placebo. Active treatment correlated with improved sleep onset, sleep maintenance, and total sleep time compared with placebo. All participants were receiving antidepressant therapy with escitalopram.

Thomas Roth, PhD, director of the Sleep Disorders and Research Center at Henry Ford Hospital, said, "The results of this study demonstrate that Ambien CR can be considered a viable treatment option for the insomnia major depressive disorder patients experience and help them get the good night's sleep they need to improve their next-day functioning."

Researchers assessed treatment efficacy through daily patient-reported Morning Sleep Questionnaires (MSQ) and during bi-weekly visits for eight weeks and every fourth week if the patients (depression responders) were part of an additional 16-week treatment period. The MSQ measured the primary efficacy outcome of total sleep time in addition to secondary measurements of sleep onset latency, wake time after sleep onset, number of awakenings, quality of sleep and sleep-related next-day functioning.

Total sleep time was increased in the active treatment group throughout the study. At Week eight, patients reporting sleeping an average of 101 minutes more than baseline compared to placebo-treated patients, who reported sleeping an average 64 minutes more. On average, zolpidem-treated patients reported falling asleep sooner and exhibited improved sleep maintenance based upon fewer nighttime awakenings and decreased wake time after sleep onset compared to placebo-treated patients.

In addition, patients reported improvements in secondary measures related to daytime functioning, including morning energy, morning concentration and sleep impact on daily activities.

Treatment-emergent adverse events occurred in 72.9 percent of the actively treated patients and 66.3 percent of patients treated with placebo. The most frequent adverse events experienced by both groups were headache (14.1 percent; 17.9 percent) and nausea (10.9 percent; 8.4 percent). Both adverse events have been reported in previous studies of both drug classes and are known to be part of the safety profile of both treatments.

"Current therapies for major depressive disorder effectively treat depression symptoms, but may not sufficiently address the sleep difficulties frequently associated with the disorder, which are primarily difficulty falling asleep and staying asleep," says Maurizio Fava, MD, Professor of Psychiatry at Harvard Medical School and Executive Vice Chair of the Department of Psychiatry at Massachusetts General Hospital. "The extended release formulation of zolpidem tartrate was found to be an effective adjunctive treatment option that helped patients fall asleep and stay asleep in this study, but may also have a positive effect on some secondary symptoms such as fatigue and lack of motivation."