Are you sleep deprived or just happy to see me?

I just finished my semester as of last week, and that final 2 week push of writing papers and case studies reminded me of something I've been meaning to share...  

Throughout most of college, I had a very predictable work habit: whenever I had a major class assignment I would put it off until the very last minute, then pull an intense tea-fuled all-nighter to finish it the night before it was due.  Full disclosure: at one point freshman year, I actually managed to do this in order to write a 1-page paper.  

The whole idea behind this strategy was that if I tilted the playing field far enough in my disfavor, I could stop worrying about my work being 'good', and instead worry about it being 'finished'.  That, and prior to these intense bouts of effort I could hang out with my buddies for whole care-free weeks at a time.  As much as I beat myself up about this pattern, I do have to admit that it worked.  The pressure definitely had a clarifying and motivating effect on my thought process.

After pulling a successful all-nighter, I'd be absolutely euphoric the following day.  I'd ride my cloud of accomplishment (or at least my cloud of not-quite-utter-failure), down to the People's Market, our student-run coffee collective, before floating over to class to turn in my assignment and then promptly crashing.  If you can believe it, those feelings of manic euphoria were among the most intense emotions I've ever felt, and I attributed them to actually meeting goals and not caving into fears.  

"Wow, it feels great not to fail!" I'd think.  "What should I do now?  ...I know, I'll go smile at that grumpy lady who works in the cafeteria!  Maybe I'll pick her a flower!" (this is an artist's rendition: my thoughts didn't begin to approach this level of coherency).

My senior year, I took a Neuroanatomy course where in passing, the professor mentioned something that finally revealed EVERYTHING I HAD BELIEVED ABOUT ALL-NIGHTERS WAS A LIE.  Well, sort of.  Remember how I had been attributing all those sparkly-bright feelings to my sense of accomplishment?   Well, turns out that sleep deprivation generates feelings of happiness and euphoria completely on its own.  In fact, the positive feelings are so strong and reliable that it has been shown to alleviate symptoms of severe chronic depression in about 40-60% of patients during clinical trials.  The effects are fleeting, with depressive symptoms usually returning once patients sleep, but it's now sometimes used in conjunction with medication as a way to 'jumpstart' more positive emotion cycles, which can then be maintained by pharmaceuticals or therapy.  There's a whole bunch of research on it and everything.  Holy crap, right?  

One theory about why sleep deprivation has this effect on mood is that it disrupts normal functioning of the limbic system (a deep structure of the brain associated with emotional regulation).  In non-depressed individuals, this disruption leads to giddiness, euphoria, and really stupid jokes, while in a subset of individuals suffering from chronic depression, it totally alleviates their symptoms.  Because of this finding, researchers hypothesize that a particular subset of individuals suffer from chronic depression directly effected by problems with limbic system regulation.  Just a theory, but I think it's pretty cool.

So, why did I decide to write about this apart from its self-evident awesomeness?  This little anecdote always stuck with me because it was a really clear, personal example of how we attribute causation using the information we have, even when that information is only a piece of the whole picture.  Before I knew anything about the direct neurological effects sleep deprivation had on emotions, my actual behavior was the only piece I had to interpret the feelings I experienced.  While I'm certain that finishing my work would have made me feel great even if I had gotten enough sleep all those times (although to be honest, I've yet to fully test this empirically), it was the combination of those feelings with the strong limbic boost that made me feel the way that I did with that level of intensity.    I think it was kind of like getting all "I love you man" when drinking; the behavior isn't due entirely to the booze, but that 8th beer really helps when it comes to telling your buddy how you've really felt all this time. 

Now for the $3 moral of the story: 

I try to take all this as reminder not to be too rigid in my convictions, especially regarding causation, because it's hard to know if my conclusion has really been based on all the pieces.  This reminder is important for me, because I have a strong tendency to try to explain, understand, and contextualize pretty much everything I come across.  I don't think this is the worst of tendencies all-in-all, but reminders like this help me keep it in check.

...

Further reading for sleep deprivation:

Here's an abstract review I found that talks about a bunch of studies on sleep deprivation and depression:

http://www.psycom.net/depression.central.sleepdep.html

Here's a really interesting review of sleep deprivation as it relates to decision-making in the military.  I get get a kick out of the picture of military commanders getting all giggly like 11 year-old girls at a sleep-over until I remember they have bombs.  

Here's the abstract:

http://www.ncbi.nlm.nih.gov/sites/entrez

and here's the actual article:

http://imagesrvr.epnet.com/embimages/pdh2/xap/xap63236.pdf