Get help now Make a donation


Learn about depression, its symptoms and possible causes, and how you can access treatment and support. Find tips on caring for yourself, and guidance for friends and family.

Mae'r dudalen hon hefyd ar gael yn Gymraeg. This link will take you to a Welsh translation of this page.

What causes depression?

There are many ideas about what causes depression. Research suggests that there’s unlikely to be one single cause.

The causes can also vary a lot between different people. For some of us, a combination of different factors may cause our depression. Or we may find that we become depressed without an obvious cause or trigger.

This page covers some possible causes of depression:

Is depression caused by a chemical imbalance?

The human brain is extremely complicated. Because antidepressants work by changing brain chemistry, some people have assumed that depression is caused by changes in brain chemistry which are then 'corrected' by the drugs. Some doctors may tell you that you have a 'chemical imbalance' and need medication to correct it.

But the evidence for this is very weak, and if changes to brain chemistry occur, we don't know whether these are the result of the depression or its cause.

Childhood experiences

Research shows that going through difficult experiences in your childhood can make you more vulnerable to experiencing depression later in life. These could include experiences like:

  • Physical, sexual or emotional abuse
  • Neglect
  • The loss of someone close to you
  • Traumatic events
  • An unsettled family situation

Difficult experiences during childhood can also have a big impact on your self-esteem. And they can affect how you learn to cope with difficult emotions and stressful situations. This could make you feel less able to cope with difficult experiences and lead to depression later in life.

Visit our page on support options for abuse to find organisations who can help if you’ve experienced abuse.

I first experienced depression at 15, after psychological abuse and domestic violence (both myself and my mother) at the hands of my father, for many years.

Life events

Some of us may experience depression after going through an unwelcome, stressful or traumatic event. There are many different types of event that might trigger depression. But some examples include:

  • Losing your job or experiencing money problems
  • Relationship problems or the end of a relationship
  • Bereavement
  • Major life changes, like changing job, moving house or getting married
  • Being physically or sexually assaulted
  • Being bullied or abused, including experiencing racism

It's not just negative experiences themselves that cause depression. How we cope with them, and the support we have around us, can also affect how likely we are to experience depression.

I started to feel that depression really took a hold after a torrid time in my job, where I was bullied – I just crumbled.

Grief and depression

Grief is a natural response to losing someone or something we love. This often includes experiencing a low mood. How long this lasts will be individual to you. This period of feeling low is referred to as bereavement.

But if you feel that what you're experiencing might be something more than grief, you can talk to your doctor about it.

Or you might want to try bereavement counselling. This may be more helpful for you than general support for depression. Cruse Bereavement Support offers support and counselling for anyone affected by bereavement.

For me, it started when my mother died. After struggling and burying things deeper, I finally cracked.

Styles of thinking

Those of us who experience certain patterns of thinking may be more likely to develop depression. For example, if we tend to blame ourselves for negative events. Or think about the same negative event over and over.

If you experience negative patterns of thinking, there are ways to get help. For example, cognitive behavioural therapy (CBT) could help you notice negative patterns of thinking. And it can help you find ways to cope.

Other mental health problems

If you experience another mental health problem, it's common to also experience depression. This might be because coping with the symptoms of another mental health problem can trigger depression. You may be more likely to experience depression if you also experience:

Physical health problems

Poor physical health can increase your risk of experiencing depression. Many health problems can be difficult to manage, and this could affect your mood. These may include:

  • Chronic, or long-term, physical health problems
  • Physical health problems that cause ongoing pain or discomfort
  • Life-threatening illnesses
  • Physical health problems that significantly change your lifestyle

There are also some physical health problems that can cause depression:

  • Conditions affecting the brain and nervous system
  • Hormonal problems, especially thyroid and parathyroid problems
  • Changes in hormones relating to the menstrual cycle or the menopause
  • Sleep problems

If you think you have any of these health problems, make sure your doctor knows about them. Some can be diagnosed by having blood tests.

If you have treatment for a physical health problem, healthcare professionals may also offer you mental health support.

Family history

Researchers have not found a specific gene that causes depression. But research has shown that if you have a close family member with depression, you're more likely to experience depression yourself.

This might be caused by our biology. But it could also be because we usually learn behaviour and ways of coping from the people around us as we grow up.

It’s likely that our genes, and the environment we grow up in, can both affect whether we develop depression.


Depression can be a side effect of many medicines.

The patient information leaflet (PIL) in the packet with your medication can tell you whether depression is a side effect. Or you could ask your doctor or pharmacist about any side effects.

If you think medication is causing your depression, you can talk to your doctor about taking an alternative. This is especially if you're expecting your treatment to last for a long time.

Recreational drugs and alcohol

Alcohol and recreational drugs can both contribute to depression. Some of us may use them to make ourselves feel better or distract ourselves. But they can make us feel worse in the long term.

See our pages on the mental health effects of recreational drugs and alcohol for more information.

Sleep, diet and exercise

Some of us may struggle with sleeping, getting active, or keeping a healthy diet. And if we find these things difficult, it can affect our mood.

These things are unlikely to cause depression on their own. But they could make us more vulnerable to it.

See our pages on food and mental health, sleep problems and physical activity for more information.

This information was published in April 2023. We will revise it in 2026.

References and bibliography available on request.

If you want to reproduce this content, see our permissions and licensing page.

arrow_upwardBack to Top