A simple definition
The NHS describes depression as a low mood that lasts for weeks or months and affects your daily life. It is more than feeling unhappy or fed up for a few days.
Depression can make ordinary things feel hard. Getting out of bed, replying to a message, cooking a meal or going to work can take huge effort. Things you used to enjoy may feel flat or pointless. Some people describe feeling sad and tearful. Others describe feeling numb or empty, as if a colour has gone out of life.
Depression is a real illness with real symptoms. It is not a sign of weakness or a personal failing, and you cannot “snap out of it” by trying harder. With the right treatment and support, the NHS says most people with depression make a full recovery.
Low mood or depression?
Everyone has times when their mood is low. Mind points out that these feelings often happen for a reason and pass on their own. A stressful week, a disappointment or a run of poor sleep can leave anyone feeling flat.
The difference is mostly about how long it lasts and how much it gets in the way.
| Low mood | Depression |
|---|---|
| Usually lifts within days or a few weeks | Lasts 2 weeks or more, often much longer |
| You can still enjoy some things | Loss of interest or enjoyment in most things |
| You can mostly keep up with daily life | Work, relationships or self-care are affected |
| Often improves as the situation improves | May carry on even when things around you improve |
The NHS suggests seeing a GP if you have had a low mood for more than 2 weeks, or if you are struggling to cope with it. You do not need to be sure it is depression before you ask for help. Working that out is part of the GP’s job. The page on symptoms of depression lists the signs to look out for.
Grief and depression
Grief after a death or other loss can look a lot like depression. The NHS lists common reactions to loss such as shock and numbness, overwhelming sadness with lots of crying, tiredness, anger and guilt. There is no right or wrong way to grieve, and these feelings are a normal response to loss.
Grief usually comes in waves. Many people find that, alongside the pain, they can still feel moments of warmth or even laughter, particularly when remembering the person. Over time the waves tend to become less frequent.
Grief can sometimes develop into depression, or the two can happen together. The NHS suggests getting help from a GP if:
- you have had a low mood for more than 2 weeks
- you feel more depressed or anxious over time
- you cannot cope with the stress of daily life
- self-help is not working
Some people have very intense grief that continues for many months or years and stops them getting on with life. This is sometimes called prolonged grief disorder, and support is available for it.
How common is depression?
Depression is one of the most common mental health conditions in the UK. The Adult Psychiatric Morbidity Survey, run for NHS England, measures how many adults have symptoms at a point in time.
In the 2023/4 survey:
- about 1 in 5 adults (20.2%) in England had a common mental health condition, such as depression or an anxiety disorder, in the week before they were surveyed
- 3.8% of adults met the criteria for a depressive episode, with rates higher in women (4.5%) than men (3.1%)
- common mental health conditions were most likely in young adults, affecting 25.8% of 16 to 24 year olds
These figures describe symptoms in a single week, so the number of people who have depression at some point in their lives is higher. Either way, if you have depression, you are far from alone.
How depression affects the body
Depression is often thought of as a problem with feelings, but it affects the whole body. Common physical effects include:
- tiredness and a lack of energy, even after rest
- sleeping badly, such as waking very early, or sleeping much more than usual
- changes in appetite and weight
- aches and pains without a clear cause
- moving or speaking more slowly than usual
- less interest in sex
Because these symptoms overlap with physical illnesses, a GP may suggest tests to rule out other causes. Getting diagnosed explains what to expect.
How depression affects thinking
Depression also changes the way you think. You may find it hard to concentrate, remember things or make decisions, even small ones.
It can also colour your thoughts in a negative way. People with depression often:
- feel guilty or blame themselves for things that are not their fault
- have low self-esteem and feel worthless
- feel hopeless about the future
- notice what went wrong and overlook what went well
These thoughts can feel completely true while you are depressed. It helps to know they are a symptom of the illness, not an accurate picture of you or your life. Treatments such as cognitive behavioural therapy (CBT) help people notice and work with these patterns.
Some people with depression have thoughts of suicide or self-harm. These thoughts are a symptom, and they can pass with support and treatment. If you have them, please tell someone and get help. The urgent help page lists who to contact, including Samaritans on 116 123.
How depression affects daily life
Over time, depression can affect many parts of life. People may avoid friends, drop hobbies and struggle at home, at work or in relationships. This can create a cycle: pulling back from life leaves fewer good experiences, which can deepen low mood.
The cycle can be broken, often in small steps. Treatment, practical self-help and support from others all play a part.
Severity: less severe and more severe
Doctors look at how many symptoms you have, how strong they are and how much they affect your life. The NICE guideline on depression in adults (NG222) groups depression into less severe (which includes mild depression) and more severe (moderate and severe depression). This helps guide which treatments are offered first.
There are also different types of depression, such as postnatal depression and seasonal affective disorder.
Where to go next
- Symptoms of depression – a fuller list, and when to see a GP
- Causes of depression – why depression happens
- Treatment – what the NHS and NICE recommend