Causes

There's no single cause of depression. It can occur for a variety of reasons and it has many different triggers.

For some people, anupsetting or stressful life event, such as bereavement , divorce, illness, redundancy and job or money worries, can be the cause.

Different causes can often combine to triggerdepression. For example, you may feel low after being ill and then experience atraumatic event, such as a bereavement, whichbrings ondepression.

People often talk about a "downward spiral" of events that leads to depression. For example, ifyour relationship withyour partner breaks down, you're likely to feel low, you may stop seeing friends and family andyou may start drinking more.All ofthis can makeyou feel worse and triggerdepression.

Some studies have also suggested that you're more likely to get depression asyou get older, and thatit's more common in people who live indifficult social and economic circumstances.

Some of the potential triggers of depression are discussed below.

Stressful events

Most peopletaketime to come to terms with stressful events, such as bereavement or a relationship breakdown. When these stressful events occur, your risk of becomingdepressed is increased if you stop seeing your friends and family and try to deal with your problems on your own.

Personality

You maybemore vulnerable todepressionif you havecertain personality traits,such aslow self-esteem or being overly self-critical. This may be because ofthe genes you've inherited from your parents, your early life experiences, or both.

Family history

If someone in your family has had depression in the past, such as a parent or sister or brother, it's more likely that you'll also develop it.

Giving birth

Some women are particularly vulnerable todepression after pregnancy. The hormonal and physical changes, as well as the added responsibility of a new life, can lead to Postnatal depression .

Loneliness

Becomingcut off from your family and friendscanincrease your risk ofdepression.

Alcohol and drugs

When life is getting them down, some people try to cope by drinking too much alcohol or taking drugs . This can result in a spiral of depression.

Cannabis can help you relax, but there's evidence that it can also bring on depression, particularly in teenagers.

"Drowning your sorrows" with a drink is also not recommended. Alcohol is categorised as a "strong depressant", which actually makes depression worse.

Illness

You may have a higher risk ofdepression if youhave alongstandingor life-threatening illness, such as coronary heart disease or cancer .

Head injuries are also an often under-recognised cause of depression. A severe head injury can trigger mood swings and emotional problems.

Some people may have an underactive thyroid (hypothyroidism) resulting from problems with their immune system. In rarer cases, a minor head injury can damage the pituitary gland, which is a pea-sized gland at the base ofyour brain that produces thyroid-stimulating hormones.

This can cause a number of symptoms, such as extreme tiredness and a lack ofinterest in sex ( loss of libido ), which can in turnlead to depression.