What Lack of Sleep Will Do to Your Mood

We’ve all been there…in those crabby moments after a night of restless (or no) sleep. Maybe you stayed up too late preparing for an important presentation, soothing a sick child or just marathoning your favorite show. Whatever the reason, today you’re feeling it. And so is everyone else in your path.

The link between sleep deprivation and mood is pretty straightforward: lack of sleep breeds negative emotions like hostility, irritability and even depression. Additionally, sleep deprivation is also associated with greater emotional reactivity. Spilling a cup of coffee isn’t just an inconvenience. It’s cause for a full-blown meltdown.

But what exactly is going on in the brain?

Here’s the short version. Some research suggests that sleep deprivation enhances negative mood due to increased amygdala activity (part of the limbic structure of the brain that is responsible for detecting fear and preparing for emergency events).

The amygdala is the reason we’re afraid of things outside of our control. It’s also responsible for emotion regulation. Lose even one night of good sleep and your brain will start reallocating its resources dedicated to objective cognitive processing, meaning your ability to regulate emotions goes out the window.

Take a look at what Professor Talma Hendler of Tel Aviv University’s Sagol School of Neuroscience had to say about this after her 2015 study on the neural basis for impaired emotional control without sleep:

“Prior to our study, it was not clear what was responsible for the emotional impairments triggered by sleep loss. We assumed that sleep loss would intensify the processing of emotional images and thus impeded brain capacity for executive functions. We were actually surprised to find that it significantly impacts the processing of both neutral and emotionally-charged images. It turns out we lose our neutrality. The ability of the brain to tell what’s important is compromised. It’s as if suddenly everything is important.”

How can we reclaim a good night’s sleep?

Humans evolved to spend roughly one third of our lifetime sleeping. That’s the classic ”8 hours every night” rule of thumb. At this ratio, your mind, body and brain will work as they’re meant to. Lose even an hour or two and your brain function will start to be compromised. The same goes for interrupted sleep.

Waking up several times throughout the night has been found to be even more detrimental to people’s positive moods than if they were to get fewer hours of sleep, but enjoy them uninterrupted.

The moral of the story? Protect your sleep. Keep digital devices out of the bedroom, go to bed when you’re sleepy and minimize every possible distraction (going to the bathroom, light creeping in through the shades). Additionally, use your days well. Exercise, eat well and manage the stresses of daily life. You’ll sleep better for it. And you’ll wake feeling refreshed and ready to take on the day — positive, energized and totally even-keeled.

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Louise A
Louise A1 months ago


Dr. Jan H
Dr. Jan Hill2 months ago


Daniel N
Past Member 2 months ago

Thank you for sharing

Emma L
Ellie L3 months ago

thanks for this

Val P
Val P3 months ago


Kathy K
Kathy K3 months ago

Great article. Thanks.

Danuta W
Danuta W3 months ago

thank you for posting

Lesa D
Lesa D3 months ago


thank you Lauren...

Anna R
Beth R3 months ago


Angela K
Angela K3 months ago

Thanks for sharing