Low moods usually pass, but what happens when you feel sad for weeks, months or even longer? Depression is an illness; it's not trivial and it’s not a sign of weakness.

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Learn about depression

In this guide to depression, we help you understand its causes and symptoms. We look at some common types of depression and what treatments are available. Knowing more will mean you’re in a better place to get support.

  • What is depression?

    Depression is an illness caused by changes in our brain chemistry. The World Health Organisation says that depression is one of the most disabling disorders, and it affects one in five women and one in ten men in their lifetime. 
    While being depressed isn't something you can just ‘snap out’ of, it can be treated. But many people who have depression never recognise their symptoms and so don't get the help or support they need.
  • Recognising the symptoms of depression

    Recognising depression in yourself is your first step towards realising you need help. So it’s important you’re familiar with the symptoms. Depression can range from feeling low most of the time (mild depression), to feeling that life is no longer worth living (clinical depression). Often, your symptoms might seem physical, not mental, and sometimes other people might notice something’s wrong before you do.

    Depression can lower your mood and make you feel hopeless, worthless and exhausted. It can affect your sleep, appetite and your physical health. And it can stop you from getting on with daily activities and interfere with your home or work life.

    If you experience five or more of the following signs or symptoms of depression for most of the day, every day, for more than two weeks, it's likely you may be depressed.

    What you might be thinking 

    • Having difficulty concentrating, remembering things and making decisions.
    • Being preoccupied with negative thoughts.
    • Having a pessimistic view of the future.
    • Having suicidal thoughts or thoughts of harming yourself.
    • Blaming yourself or feeling unnecessarily guilty about things.
    • Lacking self-confidence and self-esteem.

    How you might be feeling mentally

    • Experiencing a sense of unreality. 
    • Feeling numb, empty and helpless.
    • Feeling tearful.
    • Feeling irritable, impatient and intolerant of others.
    • Having little motivation or interest in things.
    • Getting no pleasure out of life.
    • Feeling anxious or worried, restless and agitated.
    • Feeling isolated or unable to relate to others. 

    How you might be feeling physically

    • Experiencing changes in your appetite or weight.
    • Experiencing constipation.
    • Having aches and pains without a physical cause.
    • Feeling tired and lacking energy.
    • Losing interest in sex.
    • Experiencing changes in your menstrual cycle.
    • Sleeping more or having disturbed sleep.

    How you might be behaving

    • Crying a lot. 
    • Self-harming. 
    • Not doing well at work or avoiding social contact. 
    • Distancing yourself from others, and not asking for support.
    • Neglecting your hobbies and interests.
    • Having difficulties in your home and family life.
    • Smoking, drinking or using other drugs more than usual.
    • Moving or speaking more slowly than before.
  • Causes of depression

    Depression is a complex condition. It’s difficult to identify any single cause of it, and the causes can be different for different people. You can develop it for a whole range of different reasons. And you can also become depressed for no obvious reason. 
    Our biology
    Many people don’t realise that depression can be related to our biology. For example, the children of parents who have had depression are more likely to have depression themselves. And there are other biological reasons for depression, such as taking particular prescription drugs or having an underactive thyroid. If you have diabetes or a heart condition you’re more likely to have an episode of depression. Getting a blow to your head that knocks you unconscious can also increase your risk.
    Our psychology
    The way we see the world is shaped by what we learn throughout our lives, especially when we’re young and our personalities are being established. We know that our psychological make up, which includes things like our confidence and self-esteem, influences how likely we are to develop an episode of depression. You may be more vulnerable if you have certain personality traits, such as low self-esteem or being overly self-critical.
    Our social environment
    Things in our environment will also change our risk of having a depressive episode. For instance, people with a stable relationship are less likely to become depressed even when faced with stressful events. You may be at greater risk of developing depression if you become cut off from your family and friends. Things like stress at work, financial pressures and other factors in our social environment can also contribute to an episode of depression.
    Stressful life events
    Certain events and the meaning they have for us may also contribute. Some of us are able to grieve after a bereavement without developing depression, but for others it can trigger an episode. And if different life events happen together it’s more likely you’ll become depressed. For example, you might feel low after an illness and then experience a traumatic event, such as bereavement, which brings on depression.
  • Common types of depression

    Seasonal affective disorder (SAD) (also known as winter depression)
    If your low mood is related to the seasons, you could have SAD. SAD usually comes on in autumn or winter, when there are fewer daylight hours, and gets better when the days get longer.
    Bipolar disorder (previously known as manic depression)
    If you have major mood swings, alternating between spells of depression and spells of excessively high moods (mania), you could have bipolar disorder. Manic episodes can involve harmful and risky behaviour such as gambling, spending sprees and unsafe sex. 
    Postnatal depression
    Many women get the ‘baby blues’ in the first week after giving birth. This is pretty common, but if your low mood lasts longer or begins later, you could have postnatal depression.
    Grief and depression
    Grief and depression share many of the same characteristics, but grief is a healthy, natural response to loss, while depression is an illness. Whilst grief can trigger a bout of depression, it’s important to understand the difference between grief and depression. If you’re grieving, your feelings of loss and sadness come and go, but if you’re depressed, you’ll usually have a constant feeling of sadness.
  • Treatment for depression

    There's plenty of evidence that many forms of depression are treatable. The treatment you might be offered will be dependent on your specific situation.

    This could be a programme of group exercise or a simple recommendation to increase the frequency of exercise you take.

    Self-help programmes
    Your health professional might offer you a booklet that contains a structured programme of self-help that you will follow for around 12 weeks. 
    Cognitive behavioural therapy (CBT)
    This mode of treatment is the one that has the most evidence for helping people with depression. The basic idea is that our automatic assumptions about situations shape our emotions. CBT trains you to identify those assumptions and find ways to question them or challenge them. 
    Computerised cognitive behavioural therapy (cCBT)
    cCBT is similar to CBT, but it's presented as an interactive computer programme. 
    Interpersonal therapy
    If your relationships with others are a significant factor in your depression, you might be recommended this form of therapy. It focuses on helping you manage your relationships with your friends, colleagues and family.
    Other psychological treatments
    These can include counselling, which is mainly about guiding you to manage your symptoms yourself.
    You may be offered treatment with antidepressants, normally with a type of antidepressant called a selective serotonin reuptake inhibitor (SSRI). This will seldom be offered on its own without psychological treatment. 

Next steps

If you’re depressed, you may feel that nothing can help, but taking action can actually make a big difference. See our action plan for a list of practical things you can start doing today. 
Learning about the symptoms of depression made me decide to get help