Posted by SLS on March 19, 2005, at 8:19:44
In reply to Medications and sleep, specifically REM sleep, posted by Sarah T. on March 19, 2005, at 3:09:22
Hi Sarah.
This was a great post.
> It has been known for over thirty years that release of norepinephrine, serotonin, and histamine completely ceases during REM sleep.Is it global throughout the brain or regionally specific? I imagine the visual cortex in the occipital lobes are exempt.
> We still don't know the purpose of REM sleep, but because the cells that make norepinephrine, serotonin and histamine completely stop discharging during REM sleep, several scientists have hypothesized that one function of REM sleep is to allow the neurotransmitters' receptors to rest.
>
> When receptors are constantly "bombarded" with neurotransmitters, they become desensitized. Only during REM sleep does the bombardment cease, and the receptors regain sensitivity.I have spoken to my doctor about this. It makes for a good theory. I think the way to think of it is not that they regain lost sensitivity, but rather that sleep prevents a reduction in sensitivity in the first place. Changes in receptor sensitivity take days to weeks to develop and depends on second messengers and nuclear events within the neuron.
> If this hypothesis is correct, then how does that explain the theory that sleep deprivation can treat depression?
> Sleep deprivation has never worked for me. I feel horrid when I don't get enough sleep, but some people report that sleep deprivation has an antidepressant effect.
Sleep deprivation allows me to feel improved for the first half of the day after. Of course, I pay for this the following day.
> Further, if the purpose of REM is to allow the receptors to rest, recover and regain sensitivty, then how can most antidepressants work?
> Most of the currently available antidepressants suppress REM sleep, and some doctors believe that REM suppression is essential to antidepressant efficacy (again, that has not worked for me, but then those doctors aren't talking about me).
REM sleep might not be as important as once thought. Perhaps it is more a marker of neuronal activity than a participant. It is a fact that antidepressants downregulate certain receptors. This might be because the exposure to neurotransmitter is elevated enough and chronic enough to elicit the second messenger system and gene transcription events to a degree that would not be suppressed by REM sleep anyway. This could explain the efficacy of trimipramine, mirtazapine, bupropion, and nefazodone. These drugs do not suppress REM sleep and sometimes increase it. Have you tried any of these?
> If it is true that REM sleep allows receptors to rest and regain sensitivity, that would explain why I have done so poorly on antidepressants, most of which suppress REM sleep.People who profit from sleep deprivation might be particularly apt to respond to Wellbutrin and MAOIs.
> Further, certain stages of sleep, including REM sleep, are critical for learning and memory. If AD's suppress REM sleep, that might explain why I had such a tough time learning while on AD's.
Consolidation of memory and LPT can occur in the absence of REM sleep.
> In fact, I'm convinced that if I'd been on AD's when I was in college, I probably wouldn't even have a Bachelor's degree yet. Memory impairment and amotivational syndromes are not what you want when you're trying to get through school.
Were you depressed in school? I had to drop out of college when I could no longer read, learn, and remember. These things became problematic when my depression worsened. I was naive to antidepressants at the time.
Currently, there is some research that calls into question the role that REM sleep plays in either antidepressant efficacy or memory consolidation.
I think your hypothesis regarding your own illness might be correct. I am less responsive now to those medications that had once been effective and at that time suppressed dreaming and produced discontinuation dreaming rebound. These same drugs do not work or suppress dreaming. I would assume that dreaming had been a marker of REM sleep. However, dreaming and REM are not mutually inclusive. You can dream without REM and have REM without dreaming. How do you know that you do not experience a suppression of REM sleep?
Which drugs have produced the most improvement for you? Which drugs made you feel worse?
- Scott
poster:SLS
thread:472726
URL: http://www.dr-bob.org/babble/20050317/msgs/472754.html