During the initial 2 weeks of treatment with first-line fluoxetine, patients with major depressive disorder (MDD) who spent 8 hours in bed had significantly lower depression severity and an earlier onset of remission when compared with those who spent only 6 hours in bed, one of the first studies to examine adequate sleep and antidepressant treatment response has found.

Among those who slept only 6 hours, no difference was observed between those who went to bed 2 hours later versus arising 2 hours earlier, reported J. Todd Arnedt, PhD, associate professor of psychiatry and neurology at the Sleep and Circadian Research Laboratory, University of Michigan Medical School, Ann Arbor, MI, and colleagues in the Journal of Clinical Psychiatry.

“Effective and practical clinical strategies are critically needed to improve response and remission rates to first-line antidepressant medications,” the study authors wrote. MDD affects approximately 16.5% of US adults in their lifetime.

Although one night of total sleep deprivation is shown to improve mood in 60% of patients with MDD, in those who are unmedicated, relapse in up to 80% is observed after recovery sleep. Recent studies have investigated combining sleep deprivation with medication, light therapy, and sleep schedule adjustments. Also explored as an alternative to total sleep deprivation in a laboratory setting is single-night partial sleep deprivation (4–5 hours of sleep), with repetition “during the initial 1-4 weeks of antidepressant therapy” accelerating treatment response, Dr Arnedt noted.

However, “to date, no study has assessed the effects of a modest repeated restriction of time in bed on treatment response in outpatients with depression initiating an antidepressant treatment trial.”

From September 2009 to December 2012, the investigators recruited 68 adults with DSM-IV–diagnosed MDD. Mean age was 25.4 years and 34 were women. Mean age at onset of MDD was 16.6 years and the current MDD episode, a mean of 11.6 months.

Participants were excluded if they had lifetime psychotic disorder, substance or alcohol dependence, eating disorder, posttraumatic stress disorders, and obsessive-compulsive disorder, and those post 6-month substance or alcohol abuse. The 8-hour time in bed group had more years of education than the other 2 groups (P<.005). The majority of the patients were white, unmarried, employed part-time or unemployed, and had a positive family history of MDD. About one-third of the patients had no history of prior MDD treatment; the others had received medication, psychotherapy, or both.

Each subject received 8 weeks of open-label fluoxetine 20 to 40mg and, for the first 2 weeks, was randomly assigned to 1 of 3 nightly “time in bed” conditions as adjunctive therapy: 19 adults were restricted to 8 hours in bed; 24 to 6 hours in bed, with a 2-hour bedtime delay (“late bedtime”); and 25 to 6 hours in bed with a 2-hour rise time advance (“early rise time).”