Major depressive disorder is most often treated with antidepressants, but the transition to using them is not always a smooth one.
The average time it takes a patient to respond to medication therapy is six weeks. Remission rates are only about 1/3, so most depressive patients would benefit from an overall better response to the drugs.
Researchers may have found a way to help. A study out of the University of Michigan, with experts in both psychiatry and sleep medicine, found that a sleep schedule could ultimately influence those remission rates using antidepressants, as well as response time.
Less is Not More
In the past, inpatient studies have found that sleep deprivation (four to five hours) for a single night resulted in better mood the following day for about 60% of people. Unfortunately, however, this amount of sleep deprivation is not practical or safe for people in their own homes.
This new study from U-M was published in the Journal of Clinical Psychiatry. It looked at 68 adults who were split into two groups: one group would spend six hours in bed every night for two weeks and the other group would spend eight hours in bed for the same amount of time. All patients were on an antidepressant regimen (fluoxetine).
This is the first study to look at how mood is affected in outpatients on time-in-bed restrictions. Both mood and sleep were measured every day for two weeks, and then mood was followed continuously for six weeks following that, where the patients went back to their normal sleep schedules on fluoxetine.
Dr. J. Todd Arnedt, lead investigator in the study and professor of Neurology and Psychiatry at U-M, reminds us that it is important to find safe and practical strategies to enhance depression treatments. That is why the researchers decided to look at how modest sleep deprivation can be implemented at home alongside medication therapy.
Dr. Arnedt and colleagues thought they would find what other studies on sleep and depression have found – that restricted time in bed would lead to better medication response. In fact, however, they discovered the opposite.
Those who spent eight hours in bed each night had a greater improvement in mood and medication response. These patients were nearly twice as likely to experience remission from symptoms after eight weeks of antidepressant treatment – that is 63% compared to 33% in the six-hour group. Furthermore, those in the eight-hour group responded faster to treatment.
For the first time, this study shows us that sufficient sleep may augment and accelerate depressive treatment response with antidepressants; however, as with all new findings, more research is necessary to confirm.
The Difference Between REM and Slow Wave Sleep
The people in the six-hour group were split up further into two groups: one set of patients was told to wake up two hours earlier, while the other was told to stay up two hours later. The idea was to determine whether REM (dream state) or slow-wave sleep influenced the remission and response rates. There are contradictory findings in previous studies about whether treatment response is affected by sleep stages.
After the first two weeks on this schedule, patients received a sleep study, which showed that those who stayed up later had more slow-wave sleep, while those who woke earlier had reduced REM sleep. There was no difference in response, however.
There was no link to a specific role in REM or slow-wave sleep as it relates to treatment response.
Patients were instructed to wear technology that allowed researchers to see whether the patients followed time-in-bed restrictions.
The device used was an ActiGraph, which is similar to a Fitbit, but more sensitive to sleep, using sensors to determine if the person was in bed at their assigned hours.
For the most part, those in the eight-hour group complied with their instructions; however, those in the six-hour group had a hard time following restrictions. Those in the early-rise group spent more time in bed than instructed.
These findings indicate that patients on a six-hour restriction would probably not follow the recommendations to spend only six hours in bed during the first two weeks of initial therapy, even if the whole six-hour condition showed better treatment response time. Therefore, it is notable that this strategy would not be useful in outpatient settings.
In the Future
The next step in determining if sleep affects depression treatment response time is to determine whether extending and optimizing sleep time at the initiation of antidepressant therapy would improve and accelerate response time. Optimizing sleep would require looking at sleep schedule, along with how much that person sleeps, how they sleep, their preferred sleep and wake times, as well as their sleep quality.
The researchers are looking at using more sophisticated measurement techniques as well. This includes high density EEG and brain imaging, which will assess the direct impact of REM and other sleep stage manipulation concerning treatment response.
For now, Dr. Arnedt makes the recommendation to pay more attention to how much patients are sleeping when they start their antidepressant. If starting a new therapy, patients should be cautioned against time-in-bed restrictions because there is a probability that it could affect how quickly they respond to the drug.
The ultimate goal is to identify good combinations of sleep and medication treatments that would be most effective for depression, which would be safe and practical in both outpatient and inpatient settings
Rachael Herman is a professional writer with an extensive background in medical writing, research, and language development. Her hobbies include hiking in the Rockies, cooking, and reading.