While fluoxetine was no more effective than placebo, the combination and BLT groups had response rates of approximately 76% and 50%, respectively, and these two groups were also superior in rates of remission.

Another recent study, from the Journal of Clinical Psychiatry, also found support for the use of BLT in combination with medication.3 Twenty-five patients with severe MDD who received BLT in addition to venlafaxine had a more rapid treatment response than 25 patients who received only the medication. Halfway through the eight-week trial, approximately 76 % of the combination group had reached the target goal of a Hamilton Depression Rating Scale (HDRS) score indicating mild depression, compared with 44% of the medication-only group. 

Researchers have begun to broaden the investigation to examine additional chronotherapeutic techniques that may influence depression. Results of a randomized controlled trial4 published in 2012 explored the use of “wake therapy” — also known as sleep deprivation — combined with light therapy as adjuncts to pharmaceutical treatment. All 75 participants with MDD were treated with duloxetine and divided into two conditions: One group exercised daily throughout the nine-week treatment period, while the other group received three initial sessions of wake therapy, followed by daily BLT and sleep time stabilization.

The chronotherapy group had an immediate response to treatment and showed superior outcomes to the exercise group: At the end of nine weeks, approximately 71% of the chronotherapy patients had responded to treatment, compared with 47% of the exercise group, as indicated by their scores on the 17-item Hamilton Depression Rating Scale (HAMD-17). Additionally, follow-up assessments during the 20 weeks post-treatment show a much larger rate of remission in the chronotherapy group versus the exercise group: approximately 62% versus 38%, respectively.5

In a small pilot study6 published in 2014, researchers at the Medical University of South Carolina explored the use of triple chronotherapy — consisting of sleep deprivation, bright light therapy and sleep phase advance, in which patients’ sleep and wake times are progressively moved forward — in patients with depression who were acutely suicidal. During the five-day treatment protocol, ten inpatients received chronotherapy in addition to standard care.

After treatment, their scores on the HAMD-17 and the Columbia Suicide Severity Rating Scale dropped significantly, and six patients met criteria for remission of MDD. Combined chronotherapy could also help treat drug-resistant depression in patients with bipolar disorder, a group that has high rates of suicide and for whom antidepressants are often ineffective.