Sleep, mood and anxiety

Sleep and mood are closely tied. When you feel low or worried, sleep often gets worse. When you sleep badly for weeks, your mood and nerves often get worse too. Experts call this a two-way link.^1,2

This matters because the link can work in your favor. Treating long-term sleep trouble can ease depression and anxiety, and it may even help prevent depression in some people. This page explains how the link works and what helps.

How sleep and mood affect each other

Think of sleep and mood as two wheels joined by a chain. When one turns, the other turns too.

Mental health problems can disturb sleep. Depression is a common cause of insomnia. It can make it hard to fall asleep or cause you to wake up very early and not get back to sleep. Trouble falling asleep is also common with anxiety disorders. Bipolar disorder can change sleep a great deal.²

Poor sleep can strain your mental health. Not getting enough sleep makes it harder to control your emotions and cope with change. Over time, it has been linked to depression, risk-taking and suicide.¹

Sleep loss turns up worry. In one set of studies, a night without sleep raised anxiety the next day. Brain scans showed that a part of the brain that helps calm emotions worked less well. Deep sleep seemed to help settle anxiety, and even small night-to-night drops in sleep went along with more anxiety the next day.⁵

This can become a cycle. Worry keeps you awake. Lost sleep makes you more worried and tired. Then you worry more about not sleeping.

Does insomnia lead to depression?

Insomnia does not cause depression in everyone. But it is a strong warning sign.

Researchers have followed large groups of people for years to see who develops depression. One review combined 34 of these studies, with more than 170,000 people. People with insomnia were about 2.3 times as likely to develop depression later.³

Another review looked at insomnia and several mental health conditions. People with insomnia were more likely to develop:⁴

• Depression: about 2.8 times the risk
• Anxiety: about 3.2 times the risk
• Alcohol problems and psychosis: a smaller rise in risk, based on only a few studies

These studies show a link, not proof of cause. Still, they suggest that long-term sleep trouble deserves attention, not just patience.

Does treating insomnia help mood?

Yes, for many people. This is the hopeful part.

Better sleep, better mood. A 2022 review pooled 22 studies of CBT-I in people with both insomnia and a mental health condition. CBT-I improved sleep in every group studied. It also eased depression symptoms by a moderate amount, and it helped PTSD symptoms even more.⁷ The mood benefits were clear right after treatment. They were less certain at later follow-ups, so more research is needed.⁷ Moderate evidence

Preventing depression in later life. A U.S. trial included 291 adults aged 60 and older who had insomnia but no recent depression. Half took part in CBT-I groups. The other half took sleep education classes. Over three years, about 1 in 8 people in the CBT-I group (12%) developed depression. In the education group, it was about 1 in 4 (26%).⁶ People whose insomnia stayed in remission had the lowest risk of all.⁶ Promising

Calmer thinking. A very large UK trial gave online CBT-I to more than 3,700 university students with insomnia. Their sleep improved a lot. Paranoid thoughts (feeling that others mean you harm) and hallucinations (hearing or seeing things others don't) went down a little. Better sleep seemed to explain part of that change.⁸

In daily life, this means sleep is worth treating directly. It is not just a side issue that will sort itself out.

Why insomnia needs its own treatment

Doctors used to think insomnia was only a symptom of depression or anxiety. The idea was that if you treat the main problem, sleep will follow.

Now, expert guidelines say insomnia should be treated alongside other conditions, not just seen as a sign of them.¹⁰ Sleep trouble often hangs on after depression lifts. In bipolar disorder, insomnia that remains between mood episodes may raise the chance of a relapse.¹³

What helps

Sleep medicines. Some sleep medicines may help for a time. But guidelines suggest trying CBT-I first.¹⁰ The same guideline advises against some medicines often used for sleep, such as benzodiazepines and diphenhydramine (the sleep aid in many "PM" products).¹⁰ Read sleep medicines: what to know, and talk with your doctor or pharmacist before changing anything.

Sleep and mood in later life

Sleep often changes with age. To learn what is normal and what is not, see sleep in later life.

These normal changes are not the same as insomnia. If poor sleep goes on for months and leaves you tired, cranky or low during the day, it is worth treating. The trial in adults 60 and older suggests that treating insomnia may protect mood as well as sleep.⁶ If low mood comes with poor sleep, see depression in later life.

Other sleep problems can also affect mood. Sleep apnea (pauses in breathing during sleep) can cause irritability, trouble concentrating and memory problems. It is also linked to depression.¹² Loud snoring, gasping at night or heavy daytime sleepiness are reasons to ask about sleep apnea.

When to get help

Talk with your doctor if:

• Sleep trouble happens 3 or more nights a week and has lasted more than a few weeks. See insomnia.
• You feel down, hopeless or worried most days for two weeks or more. Our check-in can help you put feelings into words.
• You suddenly need much less sleep but feel full of energy, or your thoughts are racing. This can be a sign of mania.
• You snore loudly, stop breathing in your sleep, or fall asleep during the day without meaning to.
• You are using alcohol or extra pills to get to sleep. See alcohol in later life.

Is it normal to sleep badly when I am depressed?

Yes. Depression is a common cause of insomnia. It often makes it hard to fall asleep or stay asleep.² Tell your doctor about sleep changes, because they help guide treatment.

Will my sleep get better once my depression is treated?

Sometimes, but not always. Insomnia can stay after mood improves. Guidelines recommend treating it directly, often with CBT-I.¹⁰

Can CBT-I help if I also take an antidepressant?

CBT-I can be used along with other treatments. Tell both your therapist and your doctor what you are using. Do not stop or change a medicine without talking with your doctor first.

Is it safe for older adults?

CBT-I has been tested in adults 60 and older, including the depression-prevention trial described above.⁶ Your clinician may adjust the steps if you have a fall risk, heart disease or other health problems.

Education only. This page is general information written from the sources listed. It is not medical, legal or financial advice and does not replace a doctor, therapist or lawyer who knows your situation. How we write and check pages.