What Happens to Sleep Deprived Characters?

What really happens when our characters don’t get the sleep they need? A whole range of physiological and psychological effects take place when sleep deprivation strikes. Make sure you know what’s right for your story.

We writers really love to put our characters through the wringer. We deprive them of safety, comfort, friends, food, drink and, oftentimes, sleep. After all, why should we let them rest when they could be out there being interesting?

But what really happens when our characters don't get the shut-eye they need? Let's take a look at:

  • The physiological and psychological effects of sleep deprivation.
  • What to consider when making sleep deprivation part of the plot.
  • How to put these effects to good use and create some juicy conflict.

The average adult gets around 7-8 hours of sleep a night, but they don’t necessarily need that much. Several sleep reduction studies have shown that you can function just as well when you get only 5 hours of sleep, once you get used to it (e.g., Friedman et al., 1977).

Trouble starts when deprivation is unexpected or when you’re denied sleep over longer periods.

Mild Sleep Deprivation

When deprived of just 3-4 hours of sleep in a single night, mood and vigilance levels drop. In particular, the ability to think innovatively and creatively is negatively affected, as is the speed at which you respond when vigilance is required—for example, responding to the flicker of a moving light.

Moderate Sleep Deprivation

Once you reach your second or third day of constant wakefulness, you may start to experience ‘microsleeps’. These are, as you probably guessed, short periods of sleep, usually lasting just 2-3 seconds. The eyelids droop and, though you remain sitting or standing, your ability to respond to things going on around you reduces.

Severe Sleep Deprivation

After several days of severely reduced sleep or total sleep deprivation, the effects aren’t as bad as you would think. Reaction times are reduced, performance on mentally demanding tasks is poor, and irritability is increased, but the most notable effect is in the body’s craving for sleep.

Several people who have stayed awake for days on end (think Tony Wright, who went 264 hours—11 days—without sleep) have reported the body attempting to slip into sleep whenever possible, such as while stationary and writing blog posts. But other than sleepiness, slowness and crankiness, severe sleep deprivation doesn’t seem to have that much of a negative effect on humans.

Applying Theory to Fiction


Is depriving your character of sleep already a component of your plot? If so, think carefully about the physiological and psychological effects of sleep deprivation. How will it affect your character’s mood, ability to think clearly and creatively, and level of alertness? The answer will most likely depend on how sleep deprived your character is.

What if your character needs to overlook an important detail, but you don’t know how to have her do it without her looking stupid? Consider depriving her of sleep beforehand. With her lowered levels of alertness, it’s perfectly understandable for her to miss potentially significant details.


If your character is in a situation that requires alertness, what would happen if you deprived her of sleep? Maybe her job needs her to be vigilant, she has to drive somewhere, or she’s trying to outsmart the antagonist. Depending on her level of sleep deprivation, several negative effects might occur:

If she’s only mildly deprived, she might miss an important detail due to inattention, which could have serious consequences for her. She could put herself at a disadvantage, cause others a lot of trouble, or even lose her job because of the mistake.

If she’s moderately deprived, she might slip into a microsleep while driving and cause an accident or fall asleep briefly while on watch duty and allow an undesirable to slip past.

And if she’s severely deprived, she can kiss goodbye to creative solutions to beating the baddie (but maybe she can knock him out by collapsing on him instead).