Sad man stressed holding his head.

The Emotional Effects of Sleep Deprivation

Is sleep deprivation hijacking your emotions?

I wish I had understood the emotional effects of sleep deprivation earlier. Ironically, I only realized its profound impact while working a night job years after my kids were past waking up at night. When I was in that baby and toddler phase of parenthood, it was hard to see how much sleep deprivation was affecting me. Of course I was tired! I was always tired! My parenting friends were all tired too! I accepted it as the new normal.

Fifteen years later, my youngest was almost 5, and I realized something crucial about sleep deprivation- it’s more than just being foggy and frustrated. Sleep deprivation is actually changing how my brain functions.

A Dramatic Shift in Mood

This realization came about over the course of six months of working a night job. Sometimes, I'd get as little as 2-3 hours of sleep before getting up to be with my kids.

  • One night of sleep deprivation and I seemed to rally the next day, tired but functional.
  • Two nights in a row, and I'd struggle. I'd feel grouchy, short tempered, and unable to enjoy anything.
  • Three or more nights, and I'd be severely compromised in my ability to function. My overall outlook on life would plummet. Problems that ordinarily seemed solvable suddenly felt insurmountable. I would find myself taking things personally and feeling provoked most of the time.

Then, an afternoon would free up where I could climb into bed and sleep for a good long stretch, and I would wake up seeing things in a completely new light. The difference in my mood was dramatic. 

What Does Lack of Sleep Do to the Brain?

Noticing the patterns in my negative mood helped me see it for what it really was – sleep deprivation. I began talking myself through the overwhelm and negativity and making it a priority to carve out time to sleep.

I started researching exactly how and why sleep deprivation affects us. I must admit that in spite of my own experience, I was still surprised at the overwhelmingly negative impact sleep deprivation has on our brains.  Lack of sleep causes problems with our ability to think, makes us likely to interpret people and circumstances negatively, and wreaks havoc on our ability to regulate emotions. 

Sleep Deprivation Drastically Reduces Executive Function

Executive function is your ability to sort and prioritize information. Research conducted at Tel Aviv University found that subjects who have been deprived of sleep had a compromised ability to complete tasks while being exposed to positive, negative, or neutral images.

According to Prof. Talma Hendler, who worked on the study, “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.” 

This helped me understand one of the more frustrating side effects of sleep deprivation: difficulty making decisions and getting things done. I felt overwhelmed by all the simple everyday tasks such as cleaning the house, paying bills, and making a grocery list.

I chalked it up to exhaustion. I thought perhaps I was just lacking motivation. After all, who wants to clean the house or go grocery shopping when you're tired? Looking back with well-rested eyes, I can see that it was more than just feeling tired or lacking motivation. I was experiencing decision-making paralysis because it all seemed equally important.

Sleep Deprivation Crushes Your Ability to Read People's Expressions

A study published in Sleep, Volume 33, Issue 3, 1 March 2010 shows that people experiencing sleep deprivation begin to lose the ability to distinguish between happy and angry facial expressions. Sleep-deprived participants in the study showed a bias toward interpreting things as negative.

We rely on facial expressions when we communicate with those around us. Is the person who is talking to us requesting, demanding, joking? Our ability to interpret facial expressions can be a deciding factor in what we think someone is communicating.

Sleep deprivation wasn't just making me grouchy. It was causing me to assume negativity where it didn't exist. It made it harder to give grace to my teens. I sometimes heard harshness in people's voices where none was intended. No wonder I was taking things personally and feeling provoked most of the time.

Sleep Deprivation Causes Difficulty Regulating Emotional Response

As if a compromised ability to distinguish emotions and sort information isn’t bad enough, sleep deprivation also significantly impacts our ability to regulate emotions.

Typically, when we have an emotional response, the prefrontal cortex of the brain and the amygdala work together. The amygdala may register a threat, but the prefrontal cortex decides if there is real danger and whether a response is warranted. Communication between the amygdala and the prefrontal cortex is compromised in people deprived of sleep. This makes impulse and emotional control far more difficult.

“Without enough sleep, we all become tall two year olds.” -JoJo Jensen

Learning more about the emotional effects of sleep deprivation has given me a new context for the tumultuous moods of my teens and tween. While I still hold them accountable for their behavior, knowing how sleep deprivation may be impacting them, I find myself considering the context of their moodiness and or poor behavior.

It's easy to remember that lack of sleep may cause over-sensitivity and meltdowns in young children. Why do we discount this in our older children, especially knowing they need so much more sleep than we do?

Did one of my teens struggle with insomnia last night, or was he up early finishing his geometry homework? Recognizing that sleep deprivation may play a role allows me to choose different strategies to respond to them. If I genuinely believe the effects of sleep deprivation cognitively and emotionally compromise them, I may choose to address their behavior later. It doesn't mean they are off the hook, but it does mean that I may need to offer some grace and address it after they have had some rest.

My new understanding has also given me a new way to talk about getting enough sleep with my family. Yes, they know sleep is essential, but now I can help them understand why it's crucial. We can talk about how it is impacting them in concrete terms.