Saturday, 29 November 2008


The subject of the full moon being a trigger for manic symptoms, or an amplifier of manic symptoms has come up a couple of times in my comments, here, and here, and it set me wondering, and I decided to work those ideas up into a post. It's all conjecture, not research, so view it as a layman's guesses at possible directions towards sensible hypotheses. (Yawn, disclaimer out of the way).

My first musings:

As for full moons - so many people seem to be affected by it, but there seems to be so little actual research or evidence out there. In fact the first result I found says: "Belief that the full moon is associated with psychiatric disturbance persists despite 50 years research showing no association."

Goes on to remark that "Prior to the advent of modern lighting the moon was a significant source of nocturnal illumination that affected sleep-wake cycle, tending to cause sleep deprivation around the time of full moon. This partial sleep deprivation would have been sufficient to induce mania/hypomania in susceptible bipolar patients and seizures in patients with seizure disorders. The advent of modern lighting attenuated this lunar effect, especially in modern urban areas, where most 20th century studies of lunar effects on the mind have been conducted."

Well, it's very dark where I live! But of course we have lighting indoors...

There must be some old association with moonlight - it is a very intense and strange light - magical even, to go down the road of cliche. But for there to be some ingrained connection predating modern lighting, one would have to posit some evolutionary advantage to going up during the full moon? Perhaps people got more done, made more babies, killed more animals, improved their survival prospects? Who knows, I just know that silver light feels like electricity going through me.

Anyway, I started thinking, and thought if there is a lunar connection, it probably has something to do with the ovulatory cycle. Lo and behold, some studies (generally the ones done in the 3rd and 2nd world, away from all-pervasive light pollution) show a link, with ovulation occuring around the full moon, and menstruation around the new moon.

There is also some research that shows that light affects melatonin production in the pineal gland - specifically, melatonin goes up in the dark, and falls in the light. This is part of our normal day/night circadian cycle - part of what resets our bodyclocks. Melatonin suppresses dopamine. There is some research (not enough, but some) to show that the lunar cycle has a secondary effect on melatonin.

Melatonin, menstruation, and the moon.
Sorry, it's a rat study.

In other words, we seem to have evolved to make babies at the full moon, he said, very tentatively and unscientifically. And if making babies in our hunter-gatherer times meant taking risks, staying up late, killing animals in lieu of a nice bunch of roses, and having the... erm... inclination, then maybe there is a hint of a possible natural explanation.

It may be argued that living in cities, exposed to light indoors, staring at glowing screens night and day should wreck our internal clocks, and that is certainly borne out to some extent by 1st world studies on ovulation and the lunar cycle. However, if one is exposed to the moonlight to a reasonable degree... be it just enough to make you feel it's sunny at midnight for a few days - even if it's a glimpse walking home in the evening, or shining through the curtains as you fruitlessly try to sleep, well, it may be enough to keep the cycle roughly set. Certainly where I live (no streetlights, barely any houses), and I don't smoke indoors, so spend a fair amount of time standing in the garden in the night, I would say I get a fair bit of lunatic exposure.

Something else that strikes me, regarding moonlight versus tungsten lighting (lightbulbs) - moonlight is quite white-blue opposed to the yellow-red of tungsten. I read somewhere a study on blue light being more effective at keeping people awake than yellow light.

Blue light.
Light and dark.

Of course, this accounts for people (all people) being higher at full moon. If you're high to start with, then it may well explain why things get a bit too much to handle.

Ok, enough pseudo-drivel for one night. Don't say I never try!

p.s. Final note: the women of the Sandawe apparently have a fertility ritual at the full moon where they would wave their exposed buttocks invitingly at the men. It was reading this, I'm afraid, that gave me the dreadful pun for the title for this post.


Dr. Liz Miller said...

there may be some truth in what you say!!

David said...

Sorry I'm six months late but I've just been looking at the moon. It certainly affects the tides so why not the chemicals in the Brain. I've certainly howled at it on occasion. There is something so alive about the Full Moon.

David said...

Strange! I thought you were me reading that comment, then I remembered I don't hold by that theory! The effect of gravity is bloody small - I think too small to be a cause.

I've certainly howled at it too! In fact I've scurried all over the hills on all fours in my time... (and I thought I was just being enthusiastic and ebullient...)

I've since modified my moon theory - it doesn't affect me so much in the summer. I put that down to the fact that it's fucking light all the time.

Wintertime though, it really makes a big difference.

Even a clear starry moonless night, where the starlight is harsh can do the same at the darkest part of the year.

Anyway, apologies for being 9 months late replying to your comment, atb D