After a bad night’s sleep, most people notice they are more irritable, less patient and find it harder to cope with small problems. That is not just in your head. Sleep and mental health are closely linked, and the connection works in both directions: poor sleep can affect your mood, and mental health problems can make it harder to sleep.
This article explains how sleep affects your mind, how much you need and what you can do to sleep better.
How much sleep do adults need?
The U.S. Centers for Disease Control and Prevention (CDC) recommends that adults get 7 or more hours of sleep per night. Yet around a third of adults regularly sleep less than this. Quality matters too: frequent waking, or sleep that does not leave you feeling rested, can have similar effects to sleeping too little.
How poor sleep affects your mental health
Mood and irritability
Even one or two nights of short sleep can make you more irritable and emotionally reactive. The parts of the brain that handle emotions become more sensitive, while the areas that help you stay calm and think things through work less well.
Anxiety and stress
Lack of sleep raises stress hormones and makes worries feel bigger. Many people find that anxious thoughts are harder to manage when they are tired, which can then make it even harder to fall asleep that night.
Depression
Sleep problems are very common in depression. Some people struggle with insomnia and early waking, while others sleep much more than usual. Ongoing insomnia is also linked with a higher risk of developing depression in the future.
Focus and decision-making
Tiredness affects concentration, memory and judgement. This can make work and daily tasks feel harder, which adds to stress.
How mental health affects sleep
The relationship runs both ways. Anxiety can make your mind race at bedtime. Depression can disturb sleep patterns. Conditions such as bipolar disorder and post-traumatic stress disorder (PTSD) are also closely linked to sleep problems. Treating the mental health condition often improves sleep, and improving sleep can make other treatments more effective.
Practical habits for better sleep
The NHS and other health bodies recommend these evidence-based habits, often called “sleep hygiene”:
- Keep a regular schedule. Go to bed and get up at roughly the same time every day, including weekends.
- Create a wind-down routine. Spend the last 30 to 60 minutes before bed doing something calm, such as reading, a warm shower or gentle stretching.
- Limit screens before bed. Phones and laptops keep your brain alert. Try putting them away an hour before sleep.
- Watch caffeine and alcohol. Avoid caffeine in the afternoon and evening. Alcohol may help you fall asleep, but it disrupts sleep later in the night.
- Make your bedroom sleep-friendly. Keep it dark, quiet and cool. Use the bed mainly for sleep.
- Get daylight and movement. Morning light and regular exercise help set your body clock, though intense exercise is best finished a few hours before bed.
- Do not lie awake for too long. If you cannot sleep after about 20 minutes, get up, do something relaxing in dim light and go back to bed when you feel sleepy.
- Write down worries. Keeping a notebook by the bed and writing down tomorrow’s tasks or worries can help quiet a busy mind.
What about sleep apps and supplements?
Sleep trackers can be useful for spotting patterns, but try not to become anxious about the numbers. Melatonin and other sleep supplements may help some people in specific situations, such as jet lag, but they are not a long-term solution for insomnia. Speak to a pharmacist or doctor before using them, especially if you take other medicines.
When to get help
Talk to your doctor if:
- You have had trouble sleeping for several weeks and it affects your daily life.
- You feel low, anxious or hopeless most of the time.
- Someone has noticed you snore loudly, stop breathing or gasp during sleep, which can be signs of sleep apnoea.
For long-term insomnia, a structured talking therapy called cognitive behavioural therapy for insomnia (CBT-I) is recommended as a first-line treatment and often works better than sleeping pills in the long run.
If you are having thoughts of harming yourself, seek help immediately. In the U.S., call or text 988. In the UK and Ireland, call Samaritans on 116 123.
The bottom line
Sleep and mental health are deeply connected. Aim for at least seven hours a night, keep a regular routine and give yourself time to wind down. If sleep problems or low mood continue, help is available, and treating one often improves the other.
This article is for general information only and is not a substitute for professional medical advice.
