Sleep and mental health: Everything you need to know

The relationship between sleep and mental health is often more complex than we might think. We tend to think of sleep as a break from the day’s action, a chance to recharge our batteries. But the truth is that while we sleep, our brains are actually pretty busy. 

The machinery is always going, even when you’re asleep-  Andy Warhol 

Think of sleep like a pit-stop for the race-car that is your brain. Essential maintenance takes place that makes sure your brain functions well during the day- the brain consolidates memories, processes information… sleep even helps us regulate emotion.

 If we start to think about sleep like a pit-stop for the brain, the relationship between sleep and mental health starts to become a little clearer. It also helps us to understand how poor sleep can negatively impact our mental health. And vice versa. So start your engines, and let’s take a closer look:

Sleep and emotional processing 

On some small scale, we’ve probably all felt irritable, on-edge, or overly-sensitive after a bad night’s sleep at some point. And the good news is that this can usually be set right with good sleep the following night.  This is because, as mentioned above, sleep, particularly REM sleep,  plays an important role in regulating emotion. 

A lack of sleep signals to the brain to be hypersensitive to attack (something brilliantly explained in Matthew Walker’s Why We Sleep).  The brain’s levels of stress hormones and neurotransmitters are upset. All of which explains why we feel argumentative, cranky and emotional after a lack of sleep. 

As  sleep becomes more systematically disrupted, as is the case for sufferers of chronic sleep disorders like insomnia, the regulation of emotion has been shown to become even more complicated. Research suggests that insomnia may impact our ability to process negative emotion. 

In fact, one study found that sleep-deprived people had a stronger emotional reaction to negative imagery than to neutral or positive imagery, whereas non-sleep deprived people showed no difference in their emotional reactivity.

This study is one of many that show how sleep deprivation makes it harder to handle negative emotions, which could potentially lead to a greater risk of depression. 

Sleep and mental illness: The chicken and the egg

50-80% of patients in a typical psychiatric practice are affected by chronic sleep problems, a figure that drops to 10-18% in the general adult U.S population. 

Problems like insomnia were once seen as a symptom of mental illness, but the relationship is more bidirectional.  Sleep problems are particularly common in people suffering from depression, anxiety, ADHD (Attention Deficit Disorder) and bipolar disorder. 

Sleep and depression

Between 65- 90% of people with depression also have some sort of sleep problem, and 1 in 5 suffer from sleep apnea. 

One of the first symptoms used to diagnose depression is sleep. Often people with depression either over-sleep, often late into the morning or difficult, upsetting thoughts make falling asleep and staying sleep difficult. 

It is perhaps interesting to frame this as feedback loop.  Difficult upsetting thoughts make it harder to sleep which in turn makes negative emotions more difficult to manage.

What’s more depression and sleep problems like insomnia can slow down recovery. This means that people are less likely to respond to treatment and making it harder to get better and stay better. 

Sleep and anxiety 

Sleep problems appear in around 50% of cases of General Anxiety Disorder (GAD) as well as being linked to other anxiety disorders like PTSD, OCD, panic disorders  and phobias. 

Anxiety can make falling asleep difficult, the classic lying awake staring at the ceiling while your brain races around. And of course, as with depression,  a lack of sleep once  can impact your anxiety. In fact a continued lack of sleep can engender a new anxiety around sleep itself.

Sleep and bipolar disorder

Sleep and  bipolar disorder are intricately linked. Insomnia and hypersomnia, vivid nightmares, delayed sleep phase syndrome, irregular sleep-wake schedules are prevalent among people with bipolar disorder.  

The cause-and-effect relationship between the two is perhaps less clear-cut than we might imagine. Reduced sleep can happen during a manic episode, but often happens before, perhaps even triggering the manic episode.

Sleep and ADHD 

Difficulty falling asleep, staying asleep, irritability, difficulty concentrating during the day. The overlap between sleep and ADHD is significant. Several different sleep disorders are common in children with ADHD (Restless Leg Syndrome, Periodic Limb Movement disorder and sleep-disordered breathing) and adult ADHD is linked to insomnia 75% of cases.  

Researchers are still not entirely sure how they are linked. One theory is that ADHD disrupts the circadian rhythm (or daily sleep-wake cycle). In other words, it’s hard to go to sleep at bedtime and to wake up and focus at school in the morning. Similarly, people with ADHD often feel more alert in the evening, whereas people who don’t, tend to naturally wind down at this time.  

CBTi, sleep and mental health

It can be overwhelming to see how interwoven sleep and mental illness. And as we briefly mentioned before, insomnia can transform sleep into a source of anxiety and stress in itself. This in turn perpetuates the sleep problem. Once again, another vicious cycle! 

There is good news in all of this, in the form of CBT-i, considered today as the reference treatment for insomnia by the American College of Physicians, American Psychological Association and other medical authorities.  

Cognitive Behavioral Therapy (CBT) was developed in the 1960s to treat depression. Today, different CBT branches treat different mental health problems (anxiety, eating disorders, addiction, insomnia). 

We used CBT-i as the starting block for our sleep coaching programs at Dreem and have written an entire series that breaks down how CBT-i works. Much like other branches of CBT, CBTi is  actionable and goal-orientated, focused on finding practical solutions and coping skills. All this starts by addressing the cycles of thoughts, feelings, and behaviors found at the heart of the problem.  Once these cycles have been identified, you start to break them with dedicated exercises. 

Treating mental illness can lead to some sleep improvement. However, insomnia often needs to be treated head-on or it can hang around, and  lead to relapses. But what’s particularly interesting here is that there is more and more clinical evidence showing how using CBT-i to treat insomnia can improve the symptoms of other mental health problems- notably depression and anxiety.

Sleep and mental health: Getting the right help

There are plenty of small day-to-day actions that you can take to look after your sleep and mental health. For instance, building a bedtime ritual, trying relaxation techniques, avoiding stimulants, alcohol and nicotine, eating healthily and exercising. 

If you need help with your sleep and mental health, reach out to your doctor, or mental healthcare provider to discuss treatment options that work for you. 

There are also plenty of free online resources available to you like MentalHealth.gov and Mind (in the UK), both with a list of numbers you can call. Remember mental illness isn’t a life sentence and you’re not alone.