Sleep and mental health affect each other in both directions. Conditions such as depression, anxiety, bipolar disorder and PTSD often disturb sleep. Poor sleep can then worsen them and may help bring them on (Sleep Foundation).
Researchers once saw sleep problems as just a symptom. That view is changing. A 2020 review argued that the strongest pathway is usually disrupted sleep. It called sleep a contributing cause of other mental health problems. It said treating insomnia lessens them (Freeman et al., 2020). The upshot is hopeful. Sleep is one of the most treatable parts of the picture.
If you are in crisis: if you or someone you know is struggling or having thoughts of suicide, in the U.S. call or text the 988 Suicide and Crisis Lifeline at 988 or chat at 988lifeline.org. In life-threatening situations, call 911 (NIMH). Outside the U.S., contact your local emergency number.
Not a diagnosis. This hub explains how sleep and mental health connect in general terms. Sleep changes have many causes. Only a doctor or mental health professional can tell what is going on for you.
How Sleep And Mental Health Affect Each Other
Sleep problems may be both a cause and a result of mental health problems. Research is still working out how the two interact in one person (Sleep Foundation). A few threads stand out:
- Sleep shapes emotional processing. Enough sleep, most of all REM sleep, helps the brain process emotional information. Lack of sleep seems most harmful to holding on to positive emotional memories (Sleep Foundation).
- Sleep loss changes the brain’s control systems. Sleep deficiency changes activity in parts of the brain. That makes it harder to control emotions and behavior. It has been linked to depression, suicide and risk-taking behavior (NHLBI).
- Mental health conditions disturb sleep. Depression is a frequent cause of insomnia. Trouble falling asleep is common with anxiety disorders. Bipolar disorder may cause sleep problems too (AASM Sleep Education).
- Improving sleep can improve mental health. A randomized trial enrolled 3,755 university students with insomnia. Digital CBT for insomnia reduced insomnia. It also reduced paranoia and hallucinations, with insomnia acting as the go-between (Freeman et al., 2017).
For how a single bad night changes your mood and emotional control, read how sleep affects your emotions. This hub looks at specific conditions.
Sleep Changes By Condition
| Condition | Common sleep changes | What is known |
|---|---|---|
| Depression | Trouble falling or staying asleep, waking too early, or oversleeping | Two-way link; sleep problems raise the risk of depression and of relapse |
| Anxiety disorders | Trouble falling asleep, racing thoughts, night-time panic attacks | Self-reinforcing cycle of worry and poor sleep |
| Bipolar disorder | Much less need for sleep in mania; insomnia or oversleeping in depression | Sleep disturbance is the most consistent early warning sign of mania |
| PTSD | Insomnia, repeated nightmares, fear of going to sleep | Sleep problems are part of the diagnosis and can persist after other symptoms improve |
| ADHD | Insomnia, delayed bedtimes, restless sleep | Sleep problems are common and can worsen daytime symptoms |
| Schizophrenia and psychosis | Trouble sleeping, nightmares, oversleeping, irregular sleep timing | Poor nights can worsen next-day psychotic experiences; sleep is treatable |
Sources: NIMH, NIMH, Sleep Foundation, Sleep Foundation, Sleep Foundation, Jackson et al., 2003, Freeman et al., 2025.
Depression: Too Little Sleep Or Too Much
Depression affects daily activities such as sleeping and eating. Listed symptoms include trouble sleeping, waking too early or oversleeping. Fatigue and trouble concentrating are on the list too. Older children, teens and young adults are more likely to be very sleepy. This is called hypersomnia (NIMH).
Most people with depression have sleep problems. Up to 80% have bouts of insomnia, and about 15% have hypersomnia. Some switch between the two within one episode (Sleep Foundation).
Sleep problems can raise the risk of developing depression in the first place. Ongoing sleep issues can raise the risk of relapse after successful treatment. People treated for major depression often report better sleep (Sleep Foundation).
Anxiety: The Worry And Sleep Cycle
Anxiety and poor sleep can reinforce each other. Worry causes poor sleep, and poor sleep causes more anxiety. Some people have nocturnal panic attacks. These wake them suddenly. They may have a racing heart, shortness of breath, sweating or intense fear (Sleep Foundation).
Unsure whether insomnia or an anxiety disorder is the root problem? Our guide to insomnia vs anxiety compares the two. It also covers treatment for each.
Bipolar Disorder: Sleep Changes As A Warning Sign
Sleep changes are built into bipolar mood episodes. In a manic episode, a person may need less sleep. In a depressive episode, they may have trouble falling asleep, wake too early or sleep too much (NIMH).
Sleep can also signal that an episode is coming. A systematic review covered 17 studies and 1,191 people. At least 80% of people with a mood disorder could name one or more early symptoms of relapse. The most robust early symptom of mania was sleep disturbance. A median of 77% reported it (Jackson et al., 2003).
That is why NIMH suggests keeping a routine for eating, sleeping and exercising. It also suggests a life chart or mood journal. These help spot mood swings (NIMH). A sudden drop in sleep without feeling tired is worth reporting to your care team straight away.
PTSD And Nightmares
Sleep is part of how PTSD is defined. Re-experiencing symptoms include recurring memories or dreams related to the event. Arousal symptoms include trouble falling or staying asleep. An adult must have symptoms for at least 1 month to be diagnosed (NIMH).
An estimated 80 to 90% of people with PTSD have insomnia. A majority have nightmares, sometimes about the trauma itself. Many become afraid to go to sleep. Insomnia often continues even after daytime PTSD symptoms are treated (Sleep Foundation).
Nightmares that follow trauma may occur in earlier stages of sleep. Most nightmares occur only in REM sleep. Having the same nightmare again and again is common after severe stress or trauma (AASM Sleep Education).
Nightmares can be treated. In imagery rehearsal therapy, you reimagine the nightmare with a different, less frightening outcome. It is then less disturbing if it comes back (AASM Sleep Education). For nightmares in general, see what scary dreams and nightmares mean.
ADHD
ADHD often occurs with sleep problems, anxiety and depression. This can make the conditions harder to diagnose and treat (NIMH). An estimated 25% to 50% of people with ADHD have sleep problems. These include insomnia, frequent awakenings and delayed bedtimes (Sleep Foundation).
Our guide on sleep and ADHD covers the body clock and a realistic plan. It also lists medication timing questions to raise with a doctor.
Schizophrenia And Psychosis
Most people diagnosed with schizophrenia struggle at night. Problems include trouble falling or staying asleep, nightmares, poor-quality sleep, oversleeping and sleeping at the wrong times. A bad night can worsen psychotic experiences and mood the next day.
A 2025 review calls these problems very treatable. It cites psychological therapy over about eight sessions (Freeman et al., 2025). The OASIS trial above also suggests that treating insomnia can reduce paranoia and hallucinations. It was done in students, so other groups need testing (Freeman et al., 2017).
Sleep Apnea And Mental Health
Obstructive sleep apnea causes pauses in breathing and fragmented sleep. It occurs more often in people with psychiatric conditions. It may add to their risk of serious mental distress (Sleep Foundation).
About 20% of people with depression are believed to have it (Sleep Foundation). In people with PTSD and sleep apnea, CPAP treatment may even reduce nightmares (Sleep Foundation). If you snore loudly or wake gasping, read our sleep apnea guide.
What Helps
CBT For Insomnia
Cognitive behavioral therapy for insomnia (CBT-I) is a 6- to 8-week plan. It is usually recommended as the first treatment for long-term insomnia. You can do it in person, by phone or online (NHLBI). Our CBT-I guide explains each part.
It also works when a mental health condition is present. A meta-analysis pooled 22 randomized trials in people with insomnia and a mental disorder. CBT-I reduced insomnia severity in people with depression, PTSD, alcohol dependency and psychosis or bipolar disorder.
Right after treatment, it also improved depression and PTSD symptoms. The effect on psychosis and bipolar symptoms was not significant. Effects on mental health symptoms were not significant at follow-up (Hertenstein et al., 2022).
In short, CBT-I reliably improves sleep in people with mental health conditions and may help some symptoms. It is an add-on to mental health care, not a replacement.
Treat Both Conditions
Sleep and mental health are so intertwined that treatment for both can go hand in hand. A doctor or psychiatrist can weigh the options when several conditions occur together (Sleep Foundation).
Depression, anxiety, bipolar disorder and PTSD each have their own effective therapies. Tell the professional treating you about your sleep. Tell your sleep doctor about your mental health.
Daily Habits That Support Both
- Keep a steady sleep schedule and a wind-down routine before bed (Sleep Foundation).
- Keep naps short. A nap of 10 to 20 minutes can reduce sleepiness. Longer naps may make it harder to fall asleep at night (Sleep Foundation).
- Keep a routine for meals, exercise and sleep (NIMH).
- Avoid alcohol, tobacco and caffeine in the evening. Put screens away for an hour or more before bed (Sleep Foundation).
Not sure how many hours to aim for? See how much sleep do you need. For the wider picture, including the heart, metabolism and immune system, start with how sleep affects your health.
Want to see how much your sleep problem is affecting you before talking to someone? The insomnia severity calculator gives you a score to take to your appointment.
When To Seek Help
- Symptoms of depression last most of the day, nearly every day. They last 2 weeks or more, or do not go away (NIMH).
- You notice a sharp drop in your need for sleep, racing thoughts or other changes. These came before a mood episode (NIMH).
- Nightmares, flashbacks or trouble sleeping continue for more than a month after a traumatic event (NIMH).
- Trouble sleeping goes on for weeks and affects your daily life. CBT-I is the first treatment for long-term insomnia (NHLBI). Our insomnia guide explains the options.
Start with your regular doctor or a mental health professional. If you see signs of depression in someone you know, encourage them to seek help from a mental health professional (NIMH).
In a crisis: call or text 988 or chat at 988lifeline.org in the U.S. Call 911 if a life is in danger (NIMH). Outside the U.S., contact your local emergency number.
Sleep And Mental Health FAQs
How Does Sleep Affect Mental Health?
Sleep helps the brain process emotions and control behavior. Poor sleep is linked to depression, anxiety and other conditions. It can make existing symptoms worse.
Can Poor Sleep Cause Mental Illness?
It can be a contributing cause. Studies show sleep problems often come first, and treating insomnia can reduce some symptoms. Most conditions have several causes.
Why Do I Sleep Too Much When I Am Depressed?
Oversleeping, or hypersomnia, is a recognized symptom of depression, especially in teens and young adults. It is worth mentioning to a doctor.
Is Less Need For Sleep A Sign Of Bipolar Disorder?
A decreased need for sleep is a symptom of mania. Sleep disturbance is also the most consistent early sign of a manic episode. Report it to your care team.
Does CBT-I Work If I Have Depression Or PTSD?
Yes, for sleep. Trials show it reduces insomnia in people with depression and PTSD. It can ease some of their symptoms too, alongside their usual treatment.
Why Do People With PTSD Have Nightmares?
Repeated dreams about the trauma are a re-experiencing symptom of PTSD. Imagery rehearsal therapy and other treatments can reduce them.