Mood prediction algorithm shows the importance of circadian rhythm.

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Researchers recently published the results of an interesting study that shows how circadian rhythm is intertwined with mood disorders.  They did this by tracking the activity and mood of the study participants over a two year period, and then they used a machine learning algorithm on the data to create a prediction of future mood.

Let me explain the details of the study…

The 55 study participants had all been diagnosed either with major depressive disorder (MDD) or bipolar disorder (BP I or II).

Participants wore a Fitbit daily and used a phone app to record their daily mood at 9 pm each night for the duration of the two year study period. The participants also met with a clinician regularly.

The researchers combined the mood data with the activity data which showed sleep, steps, heart rate, and light exposure (extrapolated from seasonal data).

From this data, they created a prediction algorithm using machine learning to predict the participant’s mood for the next three days. The algorithm was able to predict mood episodes with 87-94% accuracy, which is really cool. Better than the weatherman.

But what I really found interesting were the parameters that turned out to be most important to the algorithm. The machine learning program used all of the data to determine how to weigh each of the parameters included in the algorithm.

For patients with major depressive disorder, the two most important parameters were the activity level around bedtime and the deviation from normal sleep onset time. Both of those parameters would indicate that if someone was active at night instead of going to bed at their normal time, this would be the biggest predictor of depression or mood disorder the next day.

On the positive side, light exposure during the day and good sleep quality would indicate that mood was more likely to be good the next day.  Also important in predicting good mood was the number of steps taken during the day.

What can you do with this information? 
Well, if you are struggling with depression or bipolar disorder, I think this is just one more study that clearly shows the importance of circadian rhythm in mood disorders.

Getting your circadian rhythm on track is simple (but yet inconvenient and therefore difficult for some people :-).

First, establish a normal bedtime. If you need to be up by 7 am to get ready for work or school, plan on 8 hours of solid sleep. For most people, this means being in bed by 10:30 pm (which gives you a little time to fall asleep and some waking time if you get up in the night to pee).

Next, if you are going to be in bed by 10:30 pm, plan on decreasing your lighting and blocking out blue light by 8 or 8:30 pm.  Blue light signals through receptors in your retina that it is daytime, so to successfully get your circadian rhythm on track, you need to block out all blue light for several hours before bed.  Get some blue-blocking glasses and turn down the bright overhead lighting.

Finally, go outside every morning shortly after you get up. Make a cup of coffee or tea and go drink it on the deck.  Get sunlight on your face for a while each morning to reset your circadian rhythm. And then spend time being active and outside whenever possible during the day. Park a little bit farther away and walk to your destination, eat lunch at a park, take a bike ride in the afternoon…  you get the idea. Light + activity in the day.

Rinse and Repeat. Do this every day, including on the weekends. That is where it becomes a little more difficult when it comes to wanting to go out at night with friends.

Try it for a month. Get your family and friends on board and explain what you are doing. Talk to your doctor about it.  See if resetting your circadian rhythm for a month improves your mood stability…

Why do I suggest a month-long trial? This isn’t an instant cure-all pill, and it should take a week or more for your circadian rhythm to get on track. A month-long trial will let you see how you feel with a stable circadian rhythm for several weeks.

Will this miraculously cure depression and bipolar disorder for everyone? Realistically? Probably not for everyone 🙂  But, study after study shows that for the majority of people, circadian disruption is a big component of mood disorders.

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