Effects of REM sleep awakenings and related wakening paradigms on the ultradian sleep cycle and the symptoms in depression

In paper citation (Grozinger, Kogel, & Roschke, 2002).

In 1975, Vogel and colleagues executed a "heroic" experiment whereby severely depressed inpatients were chronically REM-sleep deprived for three weeks. They found that suppressing REM sleep had an antidepressant effect on patients with endogenous depression, namely depression that does not result from a stressful event. They used fifty-two patients, and the patients that responded to the REM deprivation treatment were less likely to require rehospitalization or another form of treatment in the future.

As the literature linking depression and sleep has progressed, many scientists have called for a confirmation of this study. Unfortunately, it takes a lot of time and resources to monitor sleeping patients. To work around this problem, Grozinger and colleagues developed a computer algorithm that wakes a patient up as soon as it detects REM sleep. Unfortunately, this system does not catch the initial moments of REM, and it only reduces REM sleep by about 50%.

Grozinger and colleagues do not replicate Vogel's results. Interestingly though, they show that both REM deprivation and sleep deprivation dramatically decrease a subject's self-reported symptoms of depression (both groups lowered their average score by ~7 points (out of an average of 22) after 11 days of treatment). I think that this is pretty strong evidence for the placebo effect. Every subject who participated in this experiment would have assumed that they were in the "treatment" group getting REM sleep deprivation because both sets of subjects were woken up almost 50 times each night. Thus each subject would want to deliver good news to the experimenter, and would thus focus on the progress that they had made since they started in the experiment. I also believe that the paradigm is so unique that it might "give hope" to a patient who has been treatment resistant.

I do not completely buy the theory that REM suppression is one of the main mechanisms of antidepressant therapy. For cognition, researchers are always trying to increase REM sleep to promote memory consolidation. I still assume that REM sleep deprivation is caused by something deeper that actually mediates the antidepressant effects of most medications/placebos.

'Til next time...