Summary: Researchers report that following a consistent and sufficient sleep schedule at the start of antidepressant treatment may influence how quickly and how well patients recover.
Source: University of Michigan Health System.
Medication remains a cornerstone of treatment for many people with major depressive disorder, but early response and remission are often delayed or incomplete.
Antidepressant effects can take several weeks to appear, and complete remission occurs in only about one-third of patients. Because many individuals do not fully benefit from medication alone, researchers are exploring practical, safe strategies to enhance treatment outcomes.
Investigators at the University of Michigan who specialize in psychiatry and sleep medicine evaluated whether modest changes in nightly time in bed during the first two weeks of antidepressant therapy affect treatment response and remission. The team examined whether restricting time in bed to six hours versus allowing eight hours would alter how quickly patients responded to fluoxetine and how likely they were to reach remission.
More sleep, not less
Past studies—mainly in inpatient settings—showed that extreme sleep deprivation (total or partial, roughly four to five hours) can produce a short-term mood boost for many patients with depression. However, such severe sleep loss is impractical and unsafe for most people living at home.
In this randomized outpatient trial published in the Journal of Clinical Psychiatry, 68 adults beginning fluoxetine were assigned to one of three nightly time-in-bed (TIB) schedules for the first two weeks: an eight-hour TIB, a six-hour TIB achieved by delaying bedtime two hours, or a six-hour TIB achieved by advancing rise time two hours. Sleep and mood were tracked daily during the two-week intervention and mood continued to be assessed weekly for an additional six weeks while patients stayed on fluoxetine and returned to their usual sleep patterns.
“We wanted to test a modest, safe change in time in bed that could realistically be used in outpatient care,” says J. Todd Arnedt, Ph.D., the study’s principal investigator and a University of Michigan associate professor in psychiatry and neurology. “Based on prior work with extreme sleep deprivation, we expected the restricted time-in-bed groups might show quicker improvement. Instead, we found the opposite.”
The eight-hour TIB group showed greater improvement across outcome measures. After eight weeks of antidepressant treatment, 63 percent of participants in the eight-hour group had achieved symptom remission compared with 33 percent in the combined six-hour groups. The eight-hour group also experienced a faster onset of treatment response than the participants whose time in bed was restricted.
“This is the first randomized outpatient study to indicate that providing adequate sleep opportunity at treatment initiation may accelerate and augment antidepressant response,” Arnedt notes. He emphasizes that additional research is needed to confirm and extend these findings.
Sleep architecture: REM and slow-wave sleep
The two six-hour groups allowed the investigators to explore whether shifting sleep to favor or reduce particular sleep stages mattered. One six-hour condition delayed bedtime by two hours (late bedtime), while the other advanced rise time by two hours (early rise time). Overnight polysomnography after two weeks confirmed that the early-rise group had substantially less REM sleep, whereas the late-bedtime group showed increased slow-wave (deep) sleep. Despite these physiological differences, there were no significant differences in antidepressant outcomes between the two six-hour groups.
“Our results did not support a specific role for either slow-wave sleep increases or REM suppression alone as the key to treatment response in this outpatient antidepressant trial,” Arnedt says.
Measuring adherence
Adherence to the assigned time-in-bed schedules was monitored with wrist-worn ActiGraph devices, which use movement sensing to estimate sleep more accurately than standard consumer activity trackers. The eight-hour group largely complied with the intervention. In contrast, participants in the six-hour conditions struggled to follow the schedule; those assigned to an earlier rise time spent nearly an hour more in bed than instructed.
“Even if the six-hour condition had produced better outcomes, the poor adherence suggests it would be difficult to implement such a recommendation in routine outpatient care,” Arnedt explains. “A strategy that patients are unlikely to follow is not a practical clinical tool.”
Next steps
Because this trial was deliberately designed to test the effects of reducing time in bed at the start of antidepressant treatment, the researchers propose the next step is to investigate whether deliberately optimizing or extending sleep opportunity at treatment initiation can improve response. Sleep optimization would consider not only total time in bed but also individual preferences for sleep timing and the overall quality of sleep.
The team also plans to use more refined measurement techniques—such as brain imaging and high-density EEG—to study how direct manipulation of REM sleep, slow-wave sleep and other sleep features relates to antidepressant response.
In the interim, Arnedt advises clinicians and patients to pay closer attention to sleep when starting an antidepressant. Patients should be cautioned against limiting their time in bed during the early weeks of medication, since reduced sleep opportunity could slow or reduce treatment benefits.
Funding: This study received support from the National Institutes of Health, including the National Institute of Mental Health and the National Center for Research Resources.
Source: Haley Otman – University of Michigan Health System
Original research: “Effects of Restricted Time in Bed on Antidepressant Treatment Response: A Randomized Controlled Trial” by J. Todd Arnedt, PhD, et al., published online in Journal of Clinical Psychiatry, August 2016. Clinical trial registration: NCT01545843.
Abstract
Effects of Restricted Time in Bed on Antidepressant Treatment Response: A Randomized Controlled Trial
Objective: Antidepressant response is often delayed in major depressive disorder. This study compared remission rates and time to remission when antidepressant medication was combined with either six or eight hours of nightly time in bed for the initial two weeks of treatment.
Methods: Sixty-eight adults with DSM-IV major depressive disorder (mean age 25.4 years, 34 women) received eight weeks of open-label fluoxetine (20–40 mg). For the first two weeks they were randomized to one of three time-in-bed conditions: eight-hour TIB (n = 19); six-hour TIB with a two-hour bedtime delay (late bedtime, n = 24); or six-hour TIB with a two-hour rise time advance (early rise time, n = 25). Clinicians blinded to condition rated symptom severity weekly; the 17-item Hamilton Depression Rating Scale was the primary outcome.
Results: Mixed-effects models showed lower depression severity overall in the eight-hour TIB group compared with the six-hour group. By week 8, 63.2% of the eight-hour group versus 32.6% of the six-hour group achieved remission. Time to remission was earlier in the eight-hour group; there were no significant differences between the two six-hour conditions.
Conclusions: Two consecutive weeks of six-hour nightly time in bed did not accelerate or improve antidepressant response. Further research should determine whether providing adequate sleep opportunity is important to optimizing antidepressant treatment response.