Increased risk

There is no simple answer to why some people develop depression and others don’t. We know what causes influenza. We can identify the virus. But we don't know exactly what causes depression. However, we do know that depression usually occurs as an interplay between a hereditary vulnerability, and environmental factors or life events

If your parent, child or siblings have had depression, there is a 20% risk that you will develop a depressive episode at some stage during your life.

In Australia approximately 1.8 million people (9.6% of the population) reported having a long-term mental or behavioral problem, according to the 2001 census.
4% of the adult population reported a very high level of psychological distress.  11% of females and 9% of males reported having either a mental or a behavioral problem.
Single parents and single adults reported the highest rates of mental and behavioral problems (Australian Bureau of Statistics, 2003).

Sex
Studies have found that depression is more common in women than men. There is a lifetime prevalence of 5-12% in men and 10-25% in women.
Depression often manifests differently in men. This results in fewer men presenting to their doctors with symptoms and fewer diagnoses of depression in this group. Read more about symptoms in men with depression.

Age
You can develop depression at any age but the risk increases slightly for women between the ages of 40 and 50. Furthermore, the risk of developing more than one depressive episode increases with age. Read more about depression in the elderly.

Socio-economic status
The connection between socio-economic circumstances and depression is not completely clear. But there seems to be an increased risk in people with a low socio-econonomic status.

Unemployment
People with depression are unemployed more frequently than others. But we don't know whether this is caused by the fact that you become depressed because you are unemployed or whether you become unemployed because you are depressed.

Psychological trauma
Some people who have experienced psychological strain or trauma develop depression. Your reaction to psychological trauma will depend to a large degree on your genetic disposition and your personality type.

Childhood experiences
It appears that people who have been physically or sexually abused during childhood have an increased risk of developing depression. This is also true for children who experience severe trauma or loss.

Divorce
We don't know whether divorce directly increases the risk of developing depression. It is known that people with depression are more frequently divorced than others but we don't know whether people become depressed because of the divorce or whether they become divorced because of the depression.

Bereavement
The loss of a loved one and unresolved grief increases the risk of developing depression.

Illness
A serious physical illness increases the risk of developing depression. Read more about depression and physical disease.

Pregnancy and child birth
During pregnancy and the weeks and months before the birth, the risk of developing depression is increased.

Depression can present in a number ways and at a number of stages after a woman gives birth.

The ‘day three blues’
This commonly occurs in the first week and settles within another week or so Women feel tearful, and overwhelmed soon after giving birth. This usually resolves without medical treatment.

A challenging adjustment
Its not uncommon to experience low or variable mood in the first few months after giving birth. Reasons include sleep deprivation, hormonal changes, adjusting to the new baby and adjusting to motherhood and its demands etc.
This period usually settles with support, and practical help from family and friends, and without specific medical treatment.

Post-natal depression
This almost always requires medical intervention.
Read more about postnatal depression.

Stress and depression
Prolonged stress increases the risk of developing depression. Stress causes you to feel irritable, tired, and insecure. You may lose the ability to cope in your personal and professional life. You may often experience a series of physical symptoms as well such as stomach problems, sleep disturbances, headache or muscular tension.