Your Circadian Rhythm Impacts Your Mood More Than You Think

Your Circadian Rhythm Impacts Your Mood More Than You Think

Your Circadian Rhythm Impacts Your Mood More Than You Think

You might already know that you have a circadian rhythm that is crucial for your health, fitness, productivity, and virtually everything else. But what you might not have known yet is the connection between your circadian rhythm and your mood. Or better that what influences your mood is impacted by your circadian rhythm.

How does your circadian rhythm impact your mood? Your circadian rhythm controls the daily cycles of your neurochemicals, hormones, and core body temperature that explain a great part of your (positive) mood. Your (positive) mood follows its own circadian (read: daily) cycle, with peaks in the morning to noon & late afternoon to early evening. And a through in between.

Read on to get a full understanding of:

  • What the normal daily rhythm is that your mood cycles through
  • How your mood is controlled by both your social environment and your circadian rhythm
  • How you can counter mood fluctuations with three of the most beneficial and scientifically proven mood-boosting activities are
  • How you can improve your daily mood through strengthening your circadian rhythm
  • How a weakened and/ or disrupted circadian rhythm contributes to some of the most common mood disorders
  • Why you can’t go wrong strengthening your circadian rhythm
  • My personal experiences and your key takeaways

Ok, before we get started, here’s a quick overview of your circadian rhythm. In short, your body needs to do a lot of things every single day. But it cannot do all at once. So it optimizes the daily timing of these. Or, better, that’s what your circadian rhythm does.

And the timing body functions that your circadian rhythm optimizes impacts virtually everything you go through. Including your neurochemicals, your hormones, and your core body temperature. Why am I telling you this? Because those three play a crucial role in your daily mood! But let’s not get ahead of us.

Your Daily Mood Cycle

The Daily Cycle of Your Mood Fluctuations

Let’s start with the obvious. You do experience mood fluctuations throughout the day. You have phases when you are in a high positive mood. And then some others where you are in a less positive mood.

But what you might not have known is that those mood fluctuations are rather predictable. And your circadian rhythm plays a key role in this.

To make this more clear, I’ve separated the following into two sections:

  1. How your general day impacts your mood fluctuations
  2. How your circadian rhythm impacts your mood fluctuations

In the first part – about your general day – I will show you how normal and even predictable your mood fluctuations are during any given day. And the second part, I will then highlight the special role your circadian rhythm plays in this.

Let’s get started with your mood generally during any given day.

The Bimodal Mood Cycle

How Your Mood Has a Bimodal Cycle

Let me introduce you to two milestone experiments that highlight how your mood cyclically changes throughout the day.

The first milestone experiment is called “A Population Approach to the Study of Emotion” and was performed by a quartet of researchers from Stony Brook University, University of Michigan, UC San Diego, and Princeton University​1​. Most notably those researchers included Daniel Kahneman, who won the 2002 Nobel Prize in Economics in Economic Sciences​2​. And Alan Krueger, who served as chairman of the White House Council of Economic Advisers under Barack Obama.

For this study, Kahneman and colleagues collected emotions of 909 women over a working day through an approach called the Day Reconstruction Method (which they pioneered just two years prior​3​). And this works just as it sounds. The participants reconstructed their previous days. And for each distinct part of the day, they noted how they felt.

What did this study find out about your mood? Positive emotions have a bimodal pattern – this is a cyclical pattern with two peaks. Initially, your positive emotions slowly climb up until noon. Then they sharply fall. And, finally, they climb up again during the afternoon and evening.

Have a look at this bimodal pattern for the three positive mood examples of happiness, warmth, and enjoyment:

Now, when do you think negative emotions peaked? Yes, during the mid-morning and mid-afternoon. Just when the positive emotions were at their low-points. But then, in the case of reconstructing the previous day, negative emotions could just have meant the absence of positive emotions for these participants.

Let’s have a look at the second milestone experiment now, called “Diurnal and Seasonal Mood Vary With Work, Sleep, and Daylength Across Diverse Cultures”. This time with an even greater group of participants.​4​

Scott Golder and Michael Macy from the Department of Sociology at Cornell University analyzed millions of Twitter messages for changes in mood (based on their linguistic nuances). 509 million messages from 2.4 million individuals to be precise.

Now, what did this data tell? First off, positive emotions were generally higher on weekends than during the week. And the mood patterns started about two hours later on the weekends. Indicating a shifted sleep-wake-cycle on the weekends, also known as social jet lag.

Is your sleep-wake cycle also different on the weekend than during the week? Then you might just experience social jet lag: Find out all about it here: “What Is Social Jet Lag and How to Overcome It

And when it comes to how your mood changes during the day, the analysis of twitter messages showed similar effects to that of the above day reconstruction study:

  • Positive emotions are high in the morning
  • They then decrease around the start of the workday (a bit earlier than in the previous study).
  • And finally increase again in the evening, at the end of the workday.

You have guessed correct: those mood fluctuations, as well, follow that bimodal pattern. Even though the big difference lies in the morning. Whereas positive emotions start high in this study and then decrease, they started low in the above study and then increased. The difference could just lie in the form that mood indicators were given: either in real-live via twitter. Or in hindsight via the day reconstruction.

Here’s what the Scott Golder and Michael Macy, the authors of this twitter study, had to say about this daily change in mood:

“People are least happy while they commute. And most happy when they spend free time with their loved ones.”

Scott Golder & Michael Macy

Ok, so much about the confirmation of what you intuitively already knew. Let’s switch to the first circadian part of this study now.

In short, your body performs many different functions throughout the day. But it cannot perform all of these at the same time. And this is where your circadian (daily) rhythm comes into play. Your circadian rhythm optimizes the timing of all your body functions throughout every single day.​5​

And the biggest factor that impacts your circadian rhythm is your light exposure. Natural light during the day strengthens your circadian rhythm. And with artificial light in the evening and at night, it is the opposite. It weakens or even disrupts your circadian rhythm.​6​

You can find out all about how your circadian rhythm works in this post: “How Does Your Circadian Rhythm Work: All You Need to Know

Now, and probably not surprising to you, your daylength (aka your daily natural light exposure) impacts your mood. But the surprising part might just be how and when it does so.​4​

First off, the absolute daylength has no impact on your daily mood fluctuations. Neither on positive emotions nor on negative emotions.

It is the relative change in daylength that impacts your mood

  1. When your days get relatively longer, your baseline level of positive emotions (aka your positive mood) is higher. And it is the highest during the spring equinox, when the relative change in daylength is greatest.
  2. When your days get relatively shorter, it is also your baseline level of positive emotions that gets lower.
  3. The baseline level of your negative emotions, however, does not change with a change in your relative daylength.
  4. These findings also suggest that it is the lower baseline level of positive emotions that cause seasonal affective disorder (including your “winter blues”).

Ok, so much about a first glimpse into how your circadian rhythm – through the change in daylight signals – impacts your mood. Let’s have a closer look at the connection between your circadian rhythm and your mood fluctuations next.

The Circadian Impact

How Your Circadian Rhythm Impacts Your Daily Mood Cycle

Now, several factors influence your mood at any given time. And one of those is your circadian rhythm:

  1. On the one hand, there are social factors that impact your mood. These are any social activities you do, such as your daily routines of work, commuting, eating, or how you choose to spend your free time.​4​
  2. And on the other hand, there are circadian factors that impact your mood. Or, better, factors that are regulated by your circadian rhythm. These especially include neurochemicals​7​, such as your levels of dopamine or serotonin, hormones​8​, such as your levels of cortisol or melatonin, and also your core body temperature​9​.

Your circadian rhythm optimizes the timing of all the functions that your body needs to perform every single day. Because your body cannot perform them all at the same time.​5​

This means that also the levels of both your neurochemicals and your hormones are optimized throughout your day. At some times they are higher and at other times they are lower. And the same is true for the cyclical change in your core body temperature.

But – and that’s a big but – those levels are only optimized for your day if you have a strong circadian rhythm. If not, then their amplitudes (their highest points and lowest points) are not strong enough either. That means that their levels are still too high when they should be at their lowest. And still too low when they should be at their highest.

Not sure whether your lifestyle allows for a strong circadian rhythm? I highly recommend you to check out this guide for all the background information and practical tips you need: “Get Your Circadian Rhythm Back on Track: The Ultimate Guide

Now it’s time for the big reveal: How much of an impact your circadian rhythm has on your mood? Especially through regulating the daily cycles of your neurochemicals, hormones, and your core body temperature?

In their paper “Nature’s Clocks and Human Mood: The Circadian System Modulates Reward Motivation,” a team of Australian researchers had a look at exactly that: the impact of your circadian rhythm on your mood. And here’s what they found:​10​

  • 25% of your positive emotions can be explained through your circadian rhythm in laboratory settings (under something called a constant routine protocol)
  • 13% of your positive emotions can be explained through your circadian rhythm in naturalistic conditions

Ok, a circadian influence of thirteen percent might not sound that much at first sight. But let me assure you that this is still plenty enough to take you down if you either have a weak or, even worse, a disrupted circadian rhythm.

So much so, that Colleen McClung, from the University of Pittsburgh School of Medicine, wrote a scientific paper titled “How might circadian rhythms control mood? Let me count the ways…”​11​ But more about that later.

It is also important to point out that negative emotions do not follow your circadian rhythm. Presumably, because they are more reactive in nature. Just appearing when they are needed, for example when you face any (perceived) threats.​9,10​

Optimize Your Daily Mood Cycle

How to Optimize Your Daily Mood Cycle

By now, you’ve seen that your mood has a daily rhythm. And also what the impact of your circadian rhythm is on your mood:

  1. Your mood undergoes a daily rhythm. It goes up in the morning, then there’s a through (aka dip) in the early afternoon, and finally a rebound in the evening that leads to your peak positive mood.
  2. Your circadian rhythm controls a significant part of your mood. Especially through controlling the daily cycles of your neurochemicals, your hormones, and your core body temperature.

These are the two parts that lead to natural daily mood fluctuations. Now, how can you positively influence your daily mood? Well, the answer has to be divided into these two parts. And that is exactly what I’ll show you next.

Overcome Your Daily Lows

How to Overcome the Daily Lows of Your Mood Cycle

Let’s start with your normal daily mood fluctuations. And remember that it is normal to start in a relatively higher positive mood. Only to then slightly feel less positive as the day goes on. But, once you overcome your afternoon low, your daily peak will most likely follow.​1,4​

At least, statistically speaking, that would be the way you should expect your mood to behave during the day. But, then, you are not a statistic. And you can also overcome your low points – especially now that you already know when to expect them.

So, what would be the best way to boost your positive mood? I’m glad you asked! Have a look at the following three scientifically proven mood-boosting activities:

  • A quick ten to twenty-minute break will help you boost your mood. Significantly more if you take this break in nature.​12​
  • Brief meditation (or any form of mindfulness) sessions – even when you have no prior meditation experience – have positive effects on your mood.​13​
  • Exercise and movement will boost your mood​14​. Especially if you do it in nature, in a group, or to music.​15,16​

So, what does that exactly mean for you?

First, you know that your mood shows rhythmic behavior during the day. With bouts where your positive mood is reduced. Which, statistically, occur in the early afternoon. The specific rhythm of your mood might be slightly different. But it will have a rhythm nonetheless.

→ Find out when your positive mood tends to dip. This will show you when the best time for your mood-boosting activity would be: just before your daily dip.

Second, the activities that show the most potential to help you boost your mood are simply taking a break, a brief meditation session, or exercise & movement. Especially if you do them in nature, in a group or to music.

→ Find out which of these mood-boosting activities work best for you and your lifestyle.

I am a big fan of short meditation sessions (I love the headspace app for that). And of mindfulness breathing exercises that I do regularly during the day – especially in the early afternoon. And, whenever I have some spare time, I also love to exercise outside in nature.

Speaking about exercise: Did you know that the timing of exercise has a big impact on its outcome? And that there are basically two most beneficial times to exercise during the day? You can find out all about it in this post: “When Is the Best Time to Exercise – Based on Your Circadian Rhythm

What’s more? Also, mild dehydration can significantly reduce your positive mood (and cognitive performance). And while this is not coupled to your circadian rhythm, at some times, a glass of water or two might just be what you need to boost your mood.​17​

Ok, we’ve covered that mood fluctuations are a normal part of your circadian rhythm. And you generally feel least positive during the early afternoon. Because your circadian rhythm controls your neurochemicals, your hormones, and also your core body temperature. Which then impact your mood.

But what happens if you have a weak or disrupted circadian rhythm? One that cannot optimize your body functions for your day. Where the levels of your neurochemicals, your hormones, and your core body temperature are off?

Well, in this case, you’ll be able to improve your mood by strengthening your circadian rhythm.

Strengthen & Elevate Your Mood Cycle

How to Strengthen & Elevate Your Daily Mood Cycle

If you have a weak circadian rhythm, then your body cannot (fully) optimize the timing of all its functions. And, as we’ve seen, that also means that your body cannot ensure that you have the right levels of your neurochemicals, your hormones at the right time. Or that your core body follows the right cycle.

In general, a weak circadian rhythm means the following:

  • The daily curves of all your body functions are later. That means that both the highest levels will be too late and the lowest levels will be too late too.
  • Your peak levels are reduced and your curve is flattened. That means that the highest levels will be too low and the lowest levels will be too high.

Specifically, what does a weak circadian rhythm mean for your positive mood? In the first place, it means that the curves of your neurochemicals, your hormones, and your core body temperature tend to be later and flattened. And the outcome for your mood is the following:

  • Your positive mood curve is later than optimal.
  • Your peak positive mood is lower than optimal.

Now, how do you weaken or disrupt your circadian rhythm?

To answer this question, we need to take a step back first. Your circadian rhythm is not exactly twenty-four-hours long and needs external cues from your environment to align. The by far biggest external cue (also called “zeitgeber,” which literally translates as “time giver”) is light. Natural light.

But thanks to the industrialization, you spend most of your time indoors. And you have access to electrical light (and any kind of light-emitting screens) long after it got dark. This leads to two main problems:​5​

Problem 1: You don’t get enough light during the day
Problem 2: You get too much light during the evening and at night

Your body expects a lot of light during the day to adjust your internal clock. But if the light intensity is not high enough and light duration not long enough, your body cannot effectively upregulate all your functions and prepare you for the day.

And in the evening and at night, your body does not expect any light anymore. But if it still receives some, it cannot effectively downregulate all your functions and prepare you for the night.

Then, there’s another problem connected to the circadian rhythm of your organs:​18​

  • Problem 3: You eat for too long and/ or too late

In short, as long as you consume calories of any kind, your body needs to process these. That used to be crucial for our survival and is still engraved in our DNA. And only about two-to-three hours afterward – when all your digestive processes have finished – can your organs switch to their repair and rejuvenate state.

Now, you know that a weak circadian rhythm impacts your positive mood: it makes its curve lower and later. And you’ve just seen the three major problems that weaken your circadian rhythm.

So let’s have a look at each of these three problems next and connect them with some quick fixes that have proven to positively impact your mood:

#1 You don’t get enough light during the dayBright light has shown to improve your mood and vitality. The best way is to spend more time outdoors with natural sunlight. Otherwise, you can use bright light showers indoors.​19–21​
#2 You get too much light during the evening and nightBlue light especially impacts your circadian rhythm. And both modern LEDs and any screens are high in blue-light rays. Limit your time in front of those, reduce their blue-light-emissions (night mode), and use blue-light-blocking glasses if necessary.​22–24​
#3 You eat for too long and/ or too lateMake use of time-restricted-eating (also known as intermittent fasting): Simply limit the time-frame when you consume all your daily calories. Try to keep your organs working for less than half of the day.​25,26​

Ok, so much about a first overview of why your circadian rhythm is weakened and/ or disrupted and how you can fix most of it.

If you want to get the full picture, I highly recommend you to check out this guide: “Get Your Circadian Rhythm Back on Track: The Ultimate Guide

Let’s have a quick chat about seasonal affective disorder aka the “winter blues” now. Do you remember from above that this was caused by the lower baseline level of your positive emotions? And that it is especially the relatively shorter days that contribute to that?​4​

Bright light during the day can help you to control your daily mood fluctuations. And bright light during the day can also help you to manage and overcome your winter depression. At least, if the reason is that you have weakened your circadian rhythm because you are not getting enough light during the day. But more about that in the next section.​27​

Speaking about a weakened (or disrupted) circadian rhythm and your mood… Let’s have a look at the mood disorders that can occur because of just that: a weakened or disrupted circadian rhythm.

Mood Disorders

What Is the Connection Between Your Circadian Rhythm and Mood Disorders

You’ve seen above that the circadian rhythm explains only a fraction of your daily mood fluctuations. About thirteen percent in your daily life to be precise.​10​

But don’t get fooled by that low sounding number. Because messing up that part is more than enough to mess up your whole mood. Which can then lead to mood disorders.

Let me quote Colleen McClung, from the University of Pittsburgh, here, who wrote a paper called “How might circadian rhythms control mood? Let me count the ways…” where she stated the following:​11​

“Nearly all people suffering from mood disorders have significant disruptions in circadian rhythms and the sleep/wake cycle. In fact, altered sleep patterns are one of the major diagnostic criteria for these disorders.”

Colleen McClung

What does that mean for you? Well, mood disorders can be connected to a disruption in circadian rhythms.

So much about correlation. But what about causality? May I present you with another quote?

“Circadian rhythm abnormalities might be the cause of mood disruption rather than the effect of mood disruption”

Colleen McClung

Ok, circadian rhythm disruptions (aka abnormalities) might be the cause of mood disorders (aka disruptions). And nearly everyone who suffers a mood disorder also has a disruption in their circadian rhythm.

Now, let’s get more concrete next and have a look at scientifically proven connections between the circadian rhythm and mood disorders.

Disclaimer: The following is about highlighting current scientific findings but not about fixing any mood disorders. If you experience any, please do speak to your doctor.

Seasonal Affective Disorder

Seasonal Affective Disorder and Your Circadian Rhythm

Winter depression – also commonly known as the “winter blues” – is the most common form of seasonal affective disorder.​28​

If you are affected by this, then you experience major depressive episodes in winter, when days are getting shorter and shorter. And your daylight exposure is getting less and less. Which is then commonly followed by remission or even hypomania in spring, when the days are getting longer. And your daylight exposure is getting more and more.​29,30​

And, you have guessed it already, seasonal affective disorder has been linked to a disrupted circadian rhythm.​11,28,31​

Above, you have seen the importance that light has on strengthening your circadian rhythm.​6​ And you have seen that your baseline positive mood levels are reduced when your daylength gets relatively shorter.​4​

Not surprisingly, this connection between light and your circadian rhythm also explains one of the most effective treatments for your seasonal affective disorder: light therapy.​21,27​

To be more specific, bright light therapy during the day significantly decreased the depression ratings and improved the subjective mood, energy, alertness, and productivity scores.

What does that mean for you? Bright lights can help you to keep the baseline levels of your positive mood high enough. Especially when the days are getting shorter and your natural light exposure is getting less.

A high-quality daylight therapy lamp can help you to achieve this. And I’m using one (the Beurer TL 30) whenever I feel like I’d otherwise not get enough light exposure during the day.

Unipolar Depression

Unipolar Depression and Your Circadian Rhythm

Decades of research have pointed out a connection between a weak and/ or disturbed circadian rhythm and depression. And what better way would it be to highlight this connection than by citing two of the leading researchers in this field: Anne Germain and David Kupfer from the University of Pittsburgh School of Medicine. In their review paper called “Circadian Rhythm Disturbances in Depression,” they stated the following:​28​

“If circadian and sleep processes directly affect mood regulation in healthy subjects, it is not surprising the circadian and sleep disturbances associated with depression can have profound detrimental effects on mood in depressed patients.”

Anne Germain & David Kupfer

To make this connection even clearer, let me restate what it means for you to have a weak circadian rhythm:

  • The daily curves of all your body functions are later. That means that both the highest levels will be too late and the lowest levels will be too late too.
  • Your peak levels are reduced and your curve is flattened. That means that the highest levels will be too low and the lowest levels will be too high.

And now, let’s compare this to known issues of a weakened circadian rhythm that contribute to unipolar depression:

  • Generally delayed circadian rhythms with reduced peak levels.​28,32,33​ Also, many circadian genes are not expressed rhythmically in depressed patients.​34​
  • Reduced peak levels of the hormones cortisol and melatonin.​35,36​
  • Disturbed cycles of neurotransmitters, especially of the serotonergic, glutaminergic, and noradrenergic neurons.​37,38​
  • A delayed curve of body temperature with reduced peak levels.​39,40​

Ok, let me pause and repeat for a second here. There are circadian factors that impact your mood. Or, better, factors that are regulated by your circadian rhythm. And these especially include neurochemicals​7​, hormones​8​, and also your core body temperature​9​.

When you have a weakened or disrupted circadian rhythm, your curves tend to be later and flatter. And, as we’ve just seen, such a delayed curve with reduced peak levels of your neurochemicals, your hormones, and also your core body temperature is also what contributes to unipolar depression.

Not surprisingly, one form of treatment for unipolar depression includes interventions that aim at strengthening your circadian rhythm. Including light therapy (as for seasonal affective disorder) and drugs that work on entraining your internal clock (an important part for a strong circadian rhythm). And this treatment – to strengthen your circadian rhythm – has proven antidepressant effects.​31,32,41,42​

What’s more? The symptoms of depression follow their own circadian rhythm for many people. For the majority, the highest level of depression normally occurs in the morning. While for a minority, it is the opposite (also known as “reversed diurnal variation”).​28​

Bipolar Disorder

Bipolar Disorder and Your Circadian Rhythm

First off, a typical bipolar disorder has recurring episodes of mania (extreme high positive mood). Mostly with, but sometimes without episodes of depression (extreme low positive mood).​32​

And what about the connection between your circadian rhythm and bipolar disorder? A group of leading Korean researchers around Jae Kyung Chung from the Department of Neuropsychiatry at the Eulji University of Medicine in Seoul summarized this connection as follows:​43​

“Circadian rhythm hypotheses have been prominent in the explanation of major depressive disorder (MDD) and bipolar disorder (BPD). Various evidence provides support for an association between circadian rhythm dysfunction and mood disorder. Various phases of mood disorder (depressed, manic, episode prodrome, and interepisode periods) are associated with circadian rhythm abnormalities.”

Jae Kyung Chung et al.

But let’s also get one step deeper here and have a closer look at what that specifically means for your circadian rhythm. And, in the case of bipolar disorder, we need to differentiate between episodes of mania and episodes of depression. Because your circadian rhythm is disturbed in different ways for each of these. Let me explain.

First off, and in line with unipolar depression, a dampened (read: reduced peak levels) and shifted circadian rhythm is common in patients with bipolar disorder.​44,45​

But the differentiator with bipolar disorder is the direction in which the circadian rhythm is shifted:​46,47​

  • During manic phases, the circadian rhythm tends to be advanced.
  • During depressive phases, the circadian rhythm tends to be delayed (just like in unipolar depression).

Interestingly, during recovery phases, the shift tends to go to opposite directions for each episode. Circadian rhythms are delayed during the recovery of a manic episode (where they were advanced). And they are advanced during the recovery of a depressive episode (where they were delayed).​46​

Now, when it comes to people most prone to develop a bipolar disorder, research points to two distinct directions. One, they are most commonly later chronotypes​48​. And two, they tend to be supersensitive to light​49​.

Check out this guide to find out all about your chronotype: “What Are Chronotypes and How to Find Out Yours

Both of these points seem to exploit the vulnerability of your ancient circadian rhythm within your modern environments. The biggest problem? You don’t get enough (natural) light during the day. And too much (artificial) light at night. And both of these issues are worse if you are a later chronotype. And/ or supersensitive to light.​5​

Strengthen Your Circadian Rhythm

Why You Should Strengthen Your Circadian Rhythm Independent of (Diagnosed) Mood Disorders

First, let me restate again that if you feel like you are affected by any kind of mood disorder, please do speak to your doctor. This part is not intended to provide any kind of medical advice. Rather it is to show you the current research state highlighting the connection between your circadian rhythm and mood disorders.

Ok, with that out of the way, let’s have a look at your circadian rhythm and any potential mood disorders from a different perspective.

You do have a (diagnosed) mood disorderYou do not have a (diagnosed) mood disorder
The state of your circadian rhythm:Your circadian rhythm tends to be weakened and/ or disrupted if you experience any mood disorder.You tend to have a weakened and/ or disrupted circadian rhythm thanks to our modern environments.
The current state of research:Treatments that strengthen your circadian rhythm tend to improve your mood disorder.Strengthening your circadian rhythm improves your health, fitness, and performance.
General recommendation:Strengthen your circadian rhythm.Strengthen your circadian rhythm.

Having a strong circadian rhythm helps you improve your health, fitness, and performance. Independent of whether you have a (diagnosed) mood disorder. And if you have one, then it has the potential to help you treat this one too. But don’t take it from me, take it from leading researchers Chelsea Vadnie and Colleen McClung from the University of Pittsburgh Medical School:​32​

“Since treatments that directly target the circadian system are used as therapies for mood disorders (e.g., light and dark therapies, agomelatine, social rhythm therapy, and sleep phase advance), correcting circadian disruptions may stabilize a mood.”

Chelsea Vadnie & Colleen McClung

Now, do you want to find out more about how you can strengthen your circadian rhythm? Then I highly recommend you to check out this guide: “Get Your Circadian Rhythm Back on Track: The Ultimate Guide

Personal Experiences

My Personal Experiences

When it comes to my daily life, there are a few things that I do. And that help me to keep my positive mood elevated.

First and foremost, I purposefully strengthen my circadian rhythm:

  • After waking up: I do some light exercise first thing in the morning. And outside. On most days this is either an easy run or simply a walk for a few minutes around the block.
  • In the morning: I’m quite strict about getting lots of light. Preferably natural sunlight. This could be through working directly at a window or even outside. But if both are not possible then I use light showers for my desk. Actually two, one on each side of my laptop.
  • In the afternoon: I stop eating quite early to strengthen the circadian rhythm of my organs. And to give them plenty of time to repair and rejuvenate themselves.
  • In the evening/ at night: I limit the amount of artificial (blue) light that I’m exposed to. For this, I change my glasses to ones with a blue-light filter. All my screens have an automatic night mode enabled, where they reduce their blue-light spectrum. And, most importantly, I limit my screen time and have my lights set at warmer tones.

Then, I use mood-boosting activities at times when they are most beneficial to me:

  • Directly after waking up: I do a short meditation session to start my day. More often than not as the first thing in the morning when I’m still in my bed.
  • In the early afternoon: I do short mindfulness breaks with breathing exercises (e.g., taking in three deep, slow, and controlled belly-breaths).
  • In the evening: I do a longer meditation session to mentally end the day in a refreshed state.
  • Whenever I can: I love to exercise out in nature. Especially running in the forests, cycling in the mountains, or swimming in the lakes and rivers.

There’s nothing special about those daily little things that I do. And they don’t take much time out of the day either (ok, minus the exercise sessions).

But all of those combined have had a massive positive impact on my daily mood. In a sense that I basically always feel high in a positive mood. Yet relaxed and balanced. And it takes a lot to trigger any negative mood in me.

Key Takeaways

Key Takeaways

Finally, there are six key takeaways that I want to share with you about your circadian rhythm and your mood:

  1. Your mood goes through a daily cycle. And your positive emotions have a bimodal pattern (a cyclical pattern with two peaks):
    • They are high at the start of the day until around noon
    • Then they sharply fall in the early afternoon
    • And, finally, they climb up again during the afternoon and evening.
  2. Your positive mood is impacted by social factors and circadian factors, such as the levels of your neurochemicals, your hormones, and your core body temperature. Your negative mood, on the other hand, is more reactive, as an internal reaction to (perceived) threats.
  3. You can get over your daily through (low levels of positive mood) by doing scientifically proven mood-boosting activities, such as taking breaks, mindfulness & meditation, or exercise & movement. Those are even more effective if you do them in nature, in a group, or to music.
    • Find out when your positive mood tends to dip. This will show you when the best time for your mood-boosting activity would be: just before your daily dip.
    • Find out which of these mood-boosting activities work best for you and your lifestyle.
  4. If you have a weak and/ or disrupted circadian rhythm, then your positive mood curve tends to be later than optimal and your peak positive mood is lower than optimal. The three biggest reasons for this are:
    • Problem #1: You don’t get enough light during the day.
    • Problem #2: You get too much light during the evening and at night.
    • Problem #3: You eat for too long and/ or too late.
  5. A weak and/ or disrupted circadian rhythm is also linked to several main mood disorders, including seasonal affective disorder, unipolar depression, and bipolar disorder.
  6. Strengthening your circadian rhythm helps you improve your health, fitness, and performance. Independent of whether you have a (diagnosed) mood disorder.

And now back to you: If you reflect on your daily life, have you already noticed the daily cycle of your (positive) mood? And did you also find the mood-boosting activity yet that best works for you and your lifestyle?

Stay fit,

PS: If you found this information useful, spread the word and help those who would benefit most from it 🙂



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