The Dance of Sleep and Emotions

Maybe you’ve noticed that everyone’s in a bad mood on days that follow a lousy night’s sleep. It could be that it’s your sleep deprived self that’s more aware of grumpy people-and your own grumpiness isn’t helping.

Not getting enough sleep affects our health in many ways. Our immune system takes a hit, blood pressure is affected, and weight gain is a common issue. Another place we get off balance when we don’t get enough sleep is our emotional health.

Katharina Lederle, who has her PhD in human circadian physiology and behavior—known commonly as the human body clock—is a specialist in human sleep and fatigue. In her new book Sleep Sense: Improve your Sleep, Improve your Health, Lederle describes the dance between our emotional wellbeing and the quality our sleep.

• Bad mood, bad attitude. We all know that a night or not sleeping well makes negative emotions more available and noticeable than positive emotions- we are grumpy. According to Lederle, we have a harder time being aware of our own emotional state, and have a harder time interacting with other people in our life because we are less able to perceive their emotions and respond appropriately. We become less able to ‘read’ facial expressions, and rather than responding to others with empathy, we are more likely to blame others for things going wrong. Losing sleep also makes us less able to control our impulses which means we have more conflict in our day.

• Motivation. When poor sleep continues, we also lose our motivation. We lose our ability to think about what’s best for us in the long term, and instead choose the short win. Laying on the couch beats going for a walk, and we grab a bag of chips or fast food rather than cutting up a plate of veggies and cooking a healthy meal. It becomes a vicious cycle where our choices make us less likely to get a good night’s sleep, and our poor sleep increases the chances we will make poor choices. This cycle can lead to us feeling isolated and uninspired by your life.

• Neutrality. Our ability to focus is affected when we have poor sleep. Lederle writes, “this shift in attention can help regulate our emotions, because we purposely divert our attention from a negative emotional stimulus to something positive or neutral.” We also tend to focus more on negative emotions and circumstances when we are sleep deprived. One possible reason for this is that we effectively lose our ability to ignore information that doesn’t matter to us. That level that we get “set off” emotionally speaking is quite low, so we are bothered by the smallest things.
• Connections in the brain. The amygdala is a structure in our brain that processes emotional input. As a “threat radar” it tends to view most input as dangerous. The structure in our brain that keeps track of the amygdala’s response is in our prefrontal cortex, where our executive functioning happens. Poor sleep weakens the important connection between these two structures. As Lederle writes, “the amygdala can now ‘run around like an unruly child’ and shout ‘danger, ‘doom and gloom’. We then react emotionally to everything around us, but can’t really respond appropriately.

Lederle notes that sleep, especially REM sleep, that deep sleep that comes later in the sleep cycle, are “important for overnight processing and next-day regulation of your emotions.” Knowing that getting a good, full night’s sleep is crucial for our emotional health can help us shift our habits so that we create the space, and the habits that help us to get it. As Lederle suggests, “perhaps one function of sleep is to provide us with some free therapy hours.”