Diurnal Mood Variation and Your Circadian Rhythm

How your circadian rhythm affects your mood

Mood variations
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Diurnal mood variation is a symptom of depression typically characterized by feeling worse in the morning, but better as the day progresses. This symptom usually is associated with more severe or melancholic depression.

What Causes Diurnal Mood Variation?

It is not known what causes diurnal mood variation, but it is thought to be related somehow to our body's circadian rhythm, which is a natural pattern of variations in wakefulness, body temperature, blood pressure and hormonal secretion that the body progresses through during the course of a 24-hour day.

The mood is even affected in non-depressed people by circadian rhythm and how well and how long they sleep, so it's no surprise that these factors can cause serious problems in the mood of depressed people.

One study showed that particularly in vulnerable people, like those with depression, any irregularity in the internal clock, sleeping patterns and external light and dark cues, like the sun coming up or going down, can cause mood swings and instability. So if you're going to bed at midnight one night and getting up at 7:00 and then going to bed at 10:30 and getting up at 6:00 the next, you may be doing yourself harm by not being on a consistent sleep schedule. The study found that even making modest changes in when you go to bed and when you wake up can make a big difference in your mood either way.

The study further suggests that making appropriate changes to try to stabilize the relationships between your sleep cycles, eating, exercise, meal times and when you take your medication may help decrease the impact of diurnal mood variation.

Ways to Help Stabilize Your Circadian Rhythm

It is unclear if depression causes circadian rhythm disturbances or if circadian rhythm disturbances help contribute to depression. Still, there are small changes you can make to try to help stabilize your circadian rhythm that may help.

  • Go to bed and get up at the same time every day.
  • Don't take naps. If you must take a nap, make it short.
  • Make your bedroom a place that is conducive to sleeping. Keep it quiet, cool and dark.
  • Don't do any activities in your bed other than sleeping or sex. Your brain associates your bed with what you do there, so if you are watching TV or playing games, it will be harder for your brain to shut down.
  • Avoid food and drinks that may disturb your sleep, such as alcohol, caffeine, and tobacco.
  • Get your daily workout in at least four hours before bed.
  • Avoid any sort of electronic screens like phones or tablets, at least one hour before bed. The light from these screens makes our brains think it's morning and makes it harder to fall and stay asleep.
  • Consider trying light therapy. It's simple and easy and may help you sleep better. 

Even trying just a couple of these tricks may help you build a more stable sleeping and waking pattern, which may improve your mood in the morning. 


Anna Wirz-Justice, "Diurnal variation of depressive symptoms." Dialogues in Clinical Neuroscience, 10 (3), 2008.

Anne Germain and David J. Kupfer, "Circadian Rhythm Disturbances in Depression." Human Psychopharmacology: Clinical and Experimental, 23 (7), 2008.