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Depression is a common mood disorder in which you have a persistent low mood. Symptoms can affect day-to-day life and can become very distressing. Treatments include talking (psychological) treatments and antidepressant medicines. Treatment takes time to work but has a good chance of success. Some people have repeated episodes of depression and require long-term treatment to keep symptoms away.

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What is depression?

What is depression?

Depression (also known as clinical depression, major depression or major depressive disorder) is a mental health condition. The main symptom is low mood (sadness), but it can also cause many other symptoms, such as a loss of enjoyment in things, problems thinking, and difficulties with sleep or eating. To diagnose depression, symptoms have to have been present for at least two weeks.

Depression usually interferes with normal day-to-day activities in some way, such as affecting work, studying, or your social life.

Many people with depression also experience anxiety.

How common is depression?

Depression is common. It is one of the most common illnesses that GPs deal with. About 5 in 100 adults experience depression every year. Across their lifetime, about 15 out of every 100 people will experience depression, although other estimates are even higher, up to 1 in 3 people. Depression is about twice as common in women than in men, although it's possible that depression is more likely to go unrecognised in men.

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Depression symptoms

Depression can affect people in different ways and can cause a wide variety of symptoms. Signs and symptoms of depression include:

Core symptoms

  • Persistent sadness or low mood. Some people feel tearful.

  • Marked loss of interest or pleasure in activities, even for activities that you normally enjoy.

Other common symptoms

  • Disturbed sleep compared with your usual pattern. This may be difficulty in getting off to sleep, or waking early and being unable to get back to sleep. Sometimes it is sleeping too much.

  • Change in appetite. This is often a poor appetite and weight loss. Sometimes the reverse happens with comfort eating and weight gain.

  • Tiredness (fatigue), or loss of energy.

  • Agitation or slowing of movements.

  • Poor concentration or indecisiveness. For example, you may find it difficult to read, work, etc. Even simple tasks can seem difficult.

  • Feelings of worthlessness, or excessive or inappropriate guilt.

  • Recurrent thoughts of death. This is not usually a fear of death, more a preoccupation with death and dying. For some people despairing thoughts such as "life's not worth living" or "I don't care if I don't wake up" are common. Sometimes these thoughts progress into thoughts about, and even plans for, suicide.

Physical symptoms

It is also common to develop physical symptoms such as:

Some people consult a doctor at first because they have a physical symptom such as chest pains. They are concerned that they may have a physical problem such as a heart condition when it is actually due to depression.

Anxiety symptoms

Anxiety is usually considered a different condition to depression, but it's very common for people to have symptoms of both at the same time. Usually, symptoms of one or the other predominate (ie mostly anxiety, or mostly depression), but some people have equal symptoms of both (mixed anxiety and depression). Symptoms of anxiety include:

  • Feeling worried, tense, or afraid.

  • Worrying about things that might happen in the future.

  • Having panic attacks.

Symptoms of psychotic depression

Severe depression can cause symptoms of psychosis - losing contact with reality. Symptoms of psychosis in depression include:

  • Delusions: strongly-held beliefs that are false or unlikely to be true. For example, someone with psychotic depression might believe that they are dying, or have already died.

  • Hallucinations: hearing, seeing, or smelling things that are not really there. For example, someone with psychotic depression might hear voices criticising them.

Take our Am I Depressed quiz if you're worried you might be suffering from depression.

Causes of depression

We don't know exactly why depression happens. It's likely that many different things are involved, and these probably differ from person-to-person. Anyone can develop depression. Some people are more prone to it and it can develop for no apparent reason. You may have no particular problem or worry, but depression symptoms can develop quite suddenly.

An episode of depression may be triggered by:

  • Genetics - meaning the condition is passed on through families.

  • Life events - such as relationship problems, bereavement, redundancy, illness, etc.

  • Pregnancy.

  • Alcohol and drugs.

  • Menopause.

  • Loneliness.

It's often difficult to identify one single trigger for an episode of depression. More commonly, it's a mixture of different things.

Women tend to develop depression more often than men. Particularly common times for women to become depressed are after childbirth (postnatal depression) and the menopause.

Depression and physical conditions

Mental and physical health are very closely linked. It can be difficult to tell symptoms of depression apart from symptoms caused by other 'physical' health conditions.

Depression is more common in people with long-term physical health conditions. There's likely a two-way relationship between depression and other health conditions; having a long-term physical health condition can increase the risk of depression, and depression can make the physical health condition worse. For example, people with heart disease are more likely to have a heart attack if they also have depression, compared to people who have heart disease but don't have depression.

So, depression, and mental health problems generally, are important to identify and treat in people with other long-term conditions.

Undiagnosed physical conditions

Various physical conditions may at first seem to mimic depression. Doctors aim to be on the lookout for these diseases and may order tests to rule them out if one is suspected. Perhaps the most common examples are:

  • An underactive thyroid gland (hypothyroidism) - can make you feel quite low, weepy and tired. A blood test can diagnose this.

  • An underactive pituitary gland (hypopituitarism) - the pituitary gland is just under the brain. It makes various hormones which have various actions. Sometimes one hormone can be deficient; sometimes more than one. There are various symptoms that can develop. These include loss of sex drive, sexual problems, infertility, uncontrollable weight gain and feeling low, depressed and even suicidal. Blood tests can help to diagnose hypopituitarism. There are various causes of hypopituitarism, including head injury.

  • Head injury - even a relatively mild one, even many years ago. For example, studies have shown that rates of suicide (presumably related to depression) are more common than average in people who have previously had a head injury. The reason for this is not fully understood. However, one factor that may be significant in some cases is that a head injury may result in hypopituitarism, as discussed above.

  • Polymyalgia rheumatica - this condition mainly affects older people. Typical symptoms include stiffness, pain, aching, feeling depressed and tenderness of the large muscles around the shoulders and upper arms. Feeling depressed can be the first main symptom before the other symptoms predominate.

  • Early dementia - is sometimes confused with depression.

  • Certain medicines - both prescribed and street (illicit) drugs - can cause side-effects which may mimic depression.

The rest of this leaflet is about depression of unknown cause that is not associated with any physical condition.

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Depression severity

The severity of depression can vary from person to person. Severity can be divided up as:

Mild depression

People with mild depression have either low mood or loss of interest in their usual activities, alongside other depressive symptoms listed above. They may have some difficulty functioning in some parts of daily life.

Moderate depression

People with moderate depression have either low mood or loss of interest in their usual activities, alongside other depressive symptoms. They either have a large number of milder depressive symptoms, or a small number of more severe symptoms. They tend to have significant difficulties functioning in daily life.

Severe depression

People with severe depression have many or all of the symptoms of depression at a high degree, or they may have a smaller number of very intense depressive symptoms. They have serious difficulties functioning in day-to-day life.

Subthreshold depression

Whilst it's not in the current international classification of depression, some doctors find the concept of 'subthreshold depression' helpful. In subthreshold depression, there are some symptoms of depression, but they aren't severe enough to meet the criteria for depression. However, they can still be troublesome and cause distress. If this situation persists for more than two years it is sometimes called dysthymia.

In the UK, the National Institute for Health and Care Excellence (NICE) recommends categorising depression as being either 'less severe' or 'more severe':

  • Less severe depression includes subthreshold and mild depression.

  • More severe depression includes moderate and severe depression.

Questionnaires can also be used to estimate the severity of depression symptoms. A commonly-used one is called the Patient Health Questionnaire 9, or PHQ-9.

How is depression diagnosed?

Depression is diagnosed based on your symptoms. Some people also show physical signs of depression, such as being tearful or withdrawn. Sometimes, information from other people that know you can be helpful in making the diagnosis.

Other tests, such as blood tests or scans, are rarely needed, and only done if it's thought that another condition might be present, or the symptoms of depression are not typical.

There are a few different diagnostic criteria for depression. One major international definition (ICD-11) states that depression can be diagnosed if someone has at least five out of ten of the following symptoms, present for most of the day, nearly every day, for at least two weeks. One of the symptoms must be a depressed mood, or significantly reduced interest in, or pleasure from, normal activities. The ten symptoms are:

  • A depressed (low) mood.

  • Significantly reduced interest or pleasure in normal activities.

  • Reduced ability to concentrate and sustain attention or marked indecisiveness.

  • Beliefs of low self-worth or excessive or inappropriate guilt.

  • Hopelessness about the future.

  • Recurrent thoughts of death or suicidal ideation or evidence of attempted suicide.

  • Significantly disrupted sleep or excessive sleep.

  • Significant changes in appetite or weight.

  • Feeling agitated and restless, or feeling very sluggish with reduced body movement and slowing of thought processes.

  • Reduced energy or fatigue.

Depression treatment

In general, treating depression involves a combination of medication, talking therapies, and lifestyle changes. Recommended treatment will be based on your individual circumstances, your wishes, and how severe your depression is.

The treatment options for depression include:

  • Self-care and lifestyle changes.

  • Talking therapy, including cognitive behavioural therapy and other types of psychological support.

  • Medications.

Lifestyle changes and self-care

Living with depression can be extremely difficult. Making time for self-care is important. Lifestyle changes can help the symptoms of depression, particularly mild depression. They can be difficult to do when experiencing depression, but it's useful to try doing these, especially alongside the other treatments, as they can be an important part of recovery. See "Living with depression", below, for specific tips.

Cognitive behavioural therapy (CBT)

CBT is a very widely-used type of talking therapy treatment for depression and anxiety. This usually consists of eight to twelve regular sessions, either individually or with other people in the group. CBT focuses on the 'here and now' - it's not designed to look at what happened in the past, but rather focuses on how you are thinking and behaving right now. It looks at how thoughts, beliefs, attitudes, feelings and behaviour interact, and teaches coping skills to deal with things in life differently.

CBT techniques can help to break negative thought patterns.

For example, let's say you pass a friend in the street who walks past without acknowledging you. You might have an immediate negative thought, such as "she doesn't like me", or "I've done something wrong to upset her". That might lead to negative emotions of sadness and worthlessness, and might trigger other negative thoughts, such as "nobody likes me". Some people might spend the whole day ruminating about what happened.

CBT techniques can help to re-frame the situation. Instead of an immediate negative thought, you might use techniques to evaluate the situation. Are there other explanations for why your friend behaved that way? Perhaps she didn't see you. Perhaps she's very busy and stressed herself, and distracted. If that initial thought changes, the outcome can be entirely different; instead of feeling sad and guilty for the rest of the day, your mood might be unaffected. You might even give the friend a call later to check if she's OK.

Guided self-help

This involves printed or digital materials that include structured cognitive behavioural therapy (CBT), structured behavioural activation (BA), problem-solving, and materials to help you understand your mental health difficulties.

Behavioural activation (BA)

This usually consists of eight regular sessions, either individually or with up to eight people in the group. It focuses on identifying the link between your activities and your mood. It helps you to recognise patterns and plan practical changes that reduce avoidance and that focus on behaviours that are linked to improved mood.

Group exercise

This uses a physical activity programme specifically designed for people with depression. It usually consists of more than one session per week for 10 weeks. There are usually eight participants in the group and includes moderate-intensity aerobic exercise. Exercise improves depressive and anxiety symptoms. See also the separate leaflet called Exercise and Physical Activity.

Group mindfulness and meditation

This uses a programme such as mindfulness-based cognitive therapy specifically designed for people with depression. It usually consists of eight regular sessions, with 8-15 participants in the group. The focus is on concentrating on the present, observing and sitting with thoughts and feelings and bodily sensations, and breathing exercises.

Interpersonal psychotherapy (IPT)

This usually consists of 8-6 regular sessions, although additional sessions may be needed if you also have other mental or physical health problems or complex social needs. The focus is on identifying how interpersonal relationships or circumstances are related to feelings of depression, exploring emotions and how you respond to others.


This usually consists of eight regular sessions, although additional sessions may be needed for people with comorbid mental or physical health problems or complex social needs, or to address residual symptoms. The focus is on emotional processing and finding emotional meaning, to help people find their own solutions and develop coping mechanisms.

Short-term psychodynamic psychotherapy (STPP)

This usually consists of 8-16 regular sessions, although additional sessions may be needed if you also have other mental or physical health problems or complex social needs. The focus is on recognising difficult feelings in significant relationships and stressful situations, and identifying how patterns can be repeated.

Couple therapy

This may be an option for people who have a regular partner and where the relationship contributes to the depression, or, where involving the partner is considered to be of potential useful benefit.

Antidepressant medication

Antidepressant medication is one option for depression treatment. They have less benefit in less severe depression (subthreshold or mild depression) and so are usually kept as a second-line treatment in case talking therapy doesn't help. For more severe depression (moderate or severe depression), they might be recommended amongst the treatment options from the outset.

The most commonly-used type of antidepressants are selective serotonin reuptake inhibitors (SSRIs), such as sertraline, citalopram, fluoxetine, escitalopram and paroxetine. They take about two weeks before producing any benefit in mood or anxiety symptoms. They should usually be continued for at least six months after the symptoms improve, to reduce the risk of them coming back again; although some people take them for longer.

Other commonly-used antidepressants are serotonin-norepinephrine reuptake inhibitors (SNRIs) such as venlafaxine. Older antidepressants such as tricyclic antidepressants (eg, amitriptyline) are not used very often for depression any more, although may be used for other conditions.

Antidepressants can improve depressive symptoms such as low mood, poor sleep, and poor concentration. This can improve daily functioning and make it easier to deal with difficult circumstances.

Antidepressants are generally safe medications, but they have side-effects. See the Antidepressants leaflet for more.

What if I don't have any treatment?

Most people with depression will get better without treatment. However, this may take several months or even longer. (The average length of an episode of depression is 6-8 months.) Meanwhile, living with depression can be difficult and distressing (and also for your family and friends).

Relationships, employment, etc, may be seriously affected. There is also a danger that some people turn to alcohol or illegal drugs. Some people think of suicide. Therefore, many people with depression opt for treatment.

How to treat severe depression

More severe depression is often treated with a combination of CBT and antidepressant medication.

The options for treating more severe depression are otherwise similar to less severe depression but the treatments used are provided for longer periods of time.

Other treatments

For people with psychotic depression, antipsychotic medications are often used alongside antidepressants.

Electroconvulsive therapy (ECT) is sometimes used for people with severe depression which has not improved with other treatments. It can have side-effects, but can be life-saving for people who are very seriously ill with depression, when other treatments aren't working for them.

Repetitive transcranial magnetic stimulation (rTMS) involves using magnetic fields to temporarily activate and deactivate parts of the brain. It's sometimes used for people with severe depression if other treatments - talking therapy and medications - haven't worked.

St John's wort for depression

This is generally not advised. St John's wort (hypericum) is a herbal antidepressant that you can buy, without a prescription, from pharmacies. It became a popular treatment for depression. However, the UK's national guidelines for depression advise against using it because:

  • It is not clear how well it works. Although some studies suggest that it may help depression, other studies have failed to confirm this.

  • Side-effects sometimes occur. (Some people think that because St John's wort is 'natural' then it is totally safe. This is not true. It contains many chemicals which sometimes cause problems.)

  • It may react with other medicines that you may take. Sometimes the reactions can cause serious problems. For example, you should not take St John's wort if you are taking warfarin, ciclosporin, oral contraceptives, anticonvulsants, digoxin, theophylline, or certain anti-HIV medicines. Also, you should not take it at the same time as certain other prescribed antidepressants.

Living with depression

Living with depression can be really difficult. But making time for self-care can help to manage the symptoms, particularly alongside other treatments. Things to try include:

  • Try to exercise. Exercise can have a powerful effect on people's mood. Even a little bit of gentle exercise can help, such as starting with gentle stretches or chair-based exercises.

  • Try to avoid alcohol and other drugs such as cannabis or cocaine. People often use these to cope with feelings of depression, but they tend to make depression worse in the long run. Using alcohol or drugs regularly also makes it very hard to assess and treat depression.

  • Don't bottle things up and 'go it alone'. Try to tell people who are close to you how you feel. It is not weak to cry or admit that you are struggling.

  • Don't despair - most people with depression recover. It is important to remember this.

  • Do try to distract yourself by doing other things. Try doing things that do not need much concentration but can be distracting, such as watching TV. Radio or TV is useful late at night if sleeping is a problem.

  • Do eat regularly, even if you do not feel like eating. Try to eat a healthy diet.

  • Don't make any major decisions whilst you are depressed. It may be tempting to give up a job or move away to solve the problem. If at all possible you should delay any major decisions about relationships, jobs, or money until you are well again.

  • Do tell your doctor if you feel that you are getting worse, particularly if suicidal thoughts are troubling you. See the separate leaflet called Dealing with Suicidal Thoughts.

  • Sometimes a spell off work is needed. However, too long off work might not be so good, as dwelling on problems and brooding at home may make things worse. Getting back into the hurly-burly of normal life may help the healing process when things are improving. Each person is different and the ability to work will vary. Consider seeing if you can work part-time or with amended duties until recovered.

  • Sometimes a specific psychological problem can cause depression but some people are reluctant to mention it. One example is sexual abuse as a child, leading to depression or psychological difficulties as an adult. Tell your doctor if you feel something like this is the root cause of your depression. Counselling may be available for such problems.

Understanding that your symptoms are due to depression, may help you to accept that you are ill and need help. Some people ask: "Am I going mad?" It may be a relief to know that you are not going mad and that the symptoms you have are common and have been shared by many other people.

You may 'bottle up' your symptoms from friends and relatives. However, if you are open about your feelings with close family and friends, it may help them to understand and help.

Will it happen again?

A one-off episode of depression at some stage in life is common. However, some people have two, three, or more episodes of depression.

You can have treatment for each episode. But, if you are prone to repeated episodes of depression, options that may be considered by you and your doctor include the following:

  • To take an antidepressant long-term to help prevent depression from returning.

  • Mindfulness-based cognitive therapy. This may be advised (if available) for people who are currently well but have had three or more episodes of depression. This therapy is a specialist type of talking treatment. There is good evidence that it can help to prevent depression returning.

Postnatal depression

Some women develop depression just after having a baby. See the separate leaflet called Postnatal Depression.

Bipolar disorder

In some people, depression can alternate with periods of elation and overactivity (mania or hypomania). This is called bipolar disorder (sometimes called manic depression). Treatment tends to include mood stabilising medicines such as lithium. See the separate leaflet called Bipolar Disorder.

Seasonal affective disorder

Sometimes depression can be triggered by certain times of the year such as Christmas, in the new year or summer. Some people develop recurrent depression in the winter months only. This is called seasonal affective disorder (SAD). See the separate leaflet called Seasonal Affective Disorder.

Other mental health problems

Depression sometimes occurs at the same time as other mental health problems:

  • People with anxiety, panic disorder and personality disorders quite commonly also develop depression. As a rule, depression should be treated first, followed by treatment of the other disorder. In particular, anxiety will often improve following treatment of depression.

  • Eating disorders such as anorexia and bulimia may accompany depression. In this situation the eating disorder is usually the main target of treatment.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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