How Sleep and Mental Health Affect Each Other

Quick answer: Sleep and mental health are closely connected, and they influence each other in both directions. Poor sleep can worsen mood and raise the risk of conditions like anxiety and depression, and those same conditions often make sleep harder. This two-way link can become a cycle, but it can be broken. Treating sleep and mental health together, often with therapy like CBT-I and support from a professional, improves both.

Sleep and mental health are so closely linked that it's often hard to tell where one ends and the other begins. A rough night can leave you anxious and low the next day, and stress or a mental health condition can keep you staring at the ceiling. 

If you've noticed that your sleep and your mood seem to rise and fall together, you're seeing something real.

Experts now describe this as a two-way relationship. Poor sleep can affect your mental health, and your mental health can affect your sleep. Understanding how the two feed each other makes it easier to break the cycle and improve both.

How Is Sleep Connected to Mental Health?

The link between sleep and mental health starts in the brain. Sleep is not a single uniform state. It moves through stages, including rapid eye movement (REM) sleep, and each stage supports the brain in different ways.

REM sleep plays a central role in emotional health. During REM sleep, the brain processes emotional experiences from the day and helps store them as memories. Research using brain imaging has found that a night with healthy REM sleep is followed by calmer activity in the amygdala, the part of the brain that drives emotional reactions. In effect, sleep helps take the edge off difficult emotions overnight. When REM sleep is cut short or disrupted, that emotional reset doesn't fully happen, and the brain stays more reactive the next day.

This is why the traditional view that poor sleep is simply a symptom of mental health problems has changed. Researchers now describe a bidirectional relationship, meaning sleep problems can be both a cause and a consequence of mental health conditions. In fact, more than 1 in 5 U.S. adults live with a mental health condition, and a similar share don't get enough sleep, so the two frequently occur together.

How Does Poor Sleep Affect Mental Health?

Because sleep helps the brain regulate emotion, losing it takes a measurable toll on mental health.

In the short term, poor sleep makes it harder to manage emotions. After a bad night, negative feelings intensify, stress becomes harder to handle, and irritability rises. Over the longer term, the effect goes further. Insomnia doesn't just accompany mental health conditions; it can help bring them on. 

A large analysis of research found that insomnia predicts the later development of depression and anxiety, even in people who didn't have those conditions to start with.

Sleep also plays a role in more serious mental health outcomes. Research has linked ongoing sleep deprivation to a higher risk of suicidal thoughts, which is one of the reasons sleep is now treated as an important part of mental health care rather than a separate issue.

Also Read: Insomnia as a Mental Illness?

How Do Mental Health Conditions Affect Sleep?

The relationship runs the other way with equal strength. Many mental health conditions disrupt sleep, and sleep problems are so closely tied to them that sleep disturbances are part of the diagnostic process for some conditions.

The pattern varies by condition:

• Anxiety raises mental and physical arousal, producing a racing mind and tension that make it hard to fall and stay asleep. Our guide on anxiety and insomnia covers this in more detail.

• Depression can cause insomnia, or the reverse, sleeping too much while still feeling unrested.

• PTSD and trauma can bring nightmares and a heightened state of alertness that fragments sleep.

• Bipolar disorder disrupts sleep in both directions, with sharply reduced sleep during manic episodes and excessive sleep during depressive ones.

Some medications used to treat these conditions also affect sleep, in either direction. Anyone who suspects a medication is disrupting their sleep should raise it with their prescriber rather than stopping it on their own.

Also Read: Why Sleep is Important for Your Health

Sleep Apnea and Mental Health

Sleep disorders themselves are also tied to mental health. Obstructive sleep apnea (OSA), a condition in which breathing repeatedly pauses during sleep, occurs more often in people with psychiatric conditions than in the general population. 

The repeated drops in oxygen and the fragmented sleep it causes can worsen mood and mental well-being, and its effects are often strongest during REM sleep, when breathing pauses tend to last longer. 

Because OSA and depression share symptoms like fatigue and low energy, sleep apnea sometimes goes unrecognized in people being treated for a mental health condition.

Anyone who snores heavily, wakes gasping, or feels unrefreshed despite enough time in bed is worth evaluating for it.

How to Improve Both Sleep and Mental Health

Because sleep and mental health are linked, treating one can benefit the other, and improving sleep can be part of a broader mental health strategy.

• Cognitive behavioral therapy for insomnia (CBT-I): CBT-I is the most effective treatment for chronic insomnia and is recommended as the first-line option by major medical groups. It targets the thoughts and habits that keep insomnia going, and research shows that treating sleep this way can also reduce symptoms of depression and anxiety and lower suicidal thoughts.

• Sleep hygiene: Consistent habits make a measurable difference: keep a set wake time, get morning light, avoid caffeine and alcohol in the evening, put screens away before bed, and keep the bedroom cool, dark, and quiet.

• Stress management:  A wind-down routine, along with therapy, exercise, and relaxation techniques, lowers the nighttime arousal that keeps many people awake.

• Professional care:  Because sleep and mental health conditions often occur together, treating them at the same time usually works better than addressing either alone. A doctor or therapist can tailor treatment to your situation.

When to Get Help

Occasional poor sleep or low mood is normal. But it's worth contacting a healthcare provider if sleep problems or low mood last more than a couple of weeks, interfere with daily life, or feed on each other in a cycle you can't break. A provider can identify underlying causes and connect you with the right care, whether that's therapy, treatment for a sleep disorder, or support for a mental health condition.

If you're having thoughts of harming yourself, reach out for help right away. In the US, you can call or text 988 to reach the Suicide and Crisis Lifeline, which is free, confidential, and available 24/7.

A Note From Sip2Sleep

Improving sleep is an important part of caring for your mental health. Good sleep habits do much of the work, and some people prefer gentle, natural sleep support to help them wind down. Sip2Sleep® is a melatonin-free liquid sleep aid made with Montmorency tart cherry extract and Venetron® that can be used alongside good sleep hygiene. 

As with any supplement, it's wise to check with your doctor first, especially if you are taking other medications, pregnant, or breastfeeding.

References

1. Nishida M, Pearsall J, Buckner RL, Walker MP. REM sleep, prefrontal theta, and the consolidation of human emotional memory. Cereb Cortex. 2009 May;19(5):1158-66. doi: 10.1093/cercor/bhn155. Epub 2008 Oct 1. PMID: 18832332; PMCID: PMC2665156. 

2. National Institute of Mental Health. (2024, September). Mental illness. U.S. National Institutes of Health. https://www.nimh.nih.gov/health/statistics/mental-illness

3. Oh CM, Kim HY, Na HK, Cho KH, Chu MK. The Effect of Anxiety and Depression on Sleep Quality of Individuals With High Risk for Insomnia: A Population-Based Study. Front Neurol. 2019 Aug 13;10:849. doi: 10.3389/fneur.2019.00849. PMID: 31456736; PMCID: PMC6700255. 

4. Ohayon MM, Shapiro CM. Sleep disturbances and psychiatric disorders associated with posttraumatic stress disorder in the general population. Compr Psychiatry. 2000 Nov-Dec;41(6):469-78. doi: 10.1053/comp.2000.16568. PMID: 11086154.