I Learned from Mice Today

I was looking around for something new about depression and found a news article that said people who slept with the lights on tended to be more depressed than those who didn’t.  What led to this impression was a study conducted on two groups of mice that were housed in two separate rooms, both with constant 24-hour lighting.  One room had a dark, opaque tube were the first group of mice could retreat into at their own will while the other group had only a transparent tube that still allowed the light in.  At the end of the study, the  mice that could hide from the light showed less signs of depression than those who couldn’t.

I’m thinking two things with regards to the results of the study.  First, our bodies do suffer when we are exposed to erratic light patterns. Remember that our normal circadian rhythm perceives  light as a time to be active and darkness as a time to rest. When this cycle is disturbed,  our body systems are confused, thereby putting an enormous amount of stress on them to have to clear up this confusion and adapt.  Knowing that our mood-regulating hormones are majorly affected by these changes naturally adds value to the link found between abnormal light patterns and depression.

Secondly, I think the study supports claims that emotional release of any form makes people cope better with their problems.  Because mice are natural inhabitants of the dark,  the second group in the experiment showed more symptoms of depression as there was no way for them to flee the light (which could be considered a stressor because they’re biologically akin to the dark.)  On the other hand, the first group showed less symptoms because the dark tube provided them with those important moments of escape.

Relating it to humans then, the constant light represents the constancy of stressors that we face and the dark tube, the release we seek.

As for the connection between emotional release and freedom from depression, science provides answers with electrophysiologic techniques performed on persons in the depths of depression showing  marked activity of the amygdala, the main emotion-regulating region of the brain.  After therapy, the same technique will show reduced amygdalan activity.

I can’t help but make the assumption that release of our emotions provides us with the same moments of escape that made the first group of mice in the experiment exhibit less depressive symptoms.

Now, there are two lessons I learned from the article.  First, our bodies suffer from abnormal sleep-and-wake cycles even if we think they don’t.   And even if we think we’re not feeling the bad effects, it doesn’t mean there aren’t any.  One day, they will start to creep in and we won’t anymore wonder why.

Second, we need to release our emotions simply because not doing so thieves us of life’s great joys.

(The research, formally presented on October 21 in Chicago at the annual meeting of the Society for Neuroscience, will be featured in the December 28, 2009 issue of  the journal Behavioural Brain Research.)

Clinical evidence has shown that sleep deprivation has some antidepressant effect and often precedes a manic episode in certain bipolar patients.

Studies of sleep-wake and circadian rhythm disturbance in people with mood disorders “have the potential to suggest novel therapeutic approaches, both pharmacological and nonpharmacological,” Leibenluft wrote. Considering the significant adverse effects of chemical sleep aids, she recommended that clinical studies on “nonpharmacological interventions for the treatment of insomnia should receive serious consideration.”