Research shows that depression runs in families and that some people inherit genes that make it more likely for them to get depressed. Not everyone who has the genetic makeup for depression gets depressed, though. And many people who have no family history of depression have the condition. So although genes are one factor, they aren't the single cause of depression.

The effect of maternal-fetal stress on depression is currently an exciting area of research. It seems that maternal stress during pregnancy can increase the chance that the child will be prone to depression as an adult, particularly if there is a genetic vulnerability. It is thought that the mother's circulating stress hormones can influence the development of the fetus' brain during pregnancy. This altered fetal brain development occurs in ways that predispose the child to the risk of depression as an adult. Further research is still necessary to clarify how this happens.

Symptoms of Depression

A bleak outlook-nothing will ever get better and there's nothing you can do to improve your situation.

You may have physical aches and pains which appear to have no physical cause, such as back pain.

Strong feelings of worthlessness or guilt. Harsh criticism of perceived faults and mistakes.

Problems sleeping, especially in the early morning, or wanting to sleep all of the time

You spend a lot of time thinking about what has gone wrong, what will go wrong or what is wrong about yourself as a person. You may also feel guilty sometimes about being critical of others (or even thinking critically about them).

Feeling sad or "down" for a few days is not the same as exhibiting symptoms of depression. A clinical case of depression symptoms as outlined in the Diagnostic and Statistical Manual of Mental.

Having a poor appetite, no interest in food and losing weight (though some people overeat and put on weight - 'comfort eating').

Thinking about suicide - this is very common. If you feel this way, talk to somebody about it. If you think somebody else might be thinking this way, ask them about it - IT WILL NOT MAKE THEM MORE LIKELY TO COMMIT SUICIDE.

Significant changes in weight when not attempting to gain or lose (a gain or loss of 5% or more in a month) may be indicative of depression. In children, this may also present as a failure to make expected weight gains.

Causes of Depression

Biochemical: Some evidence from high-tech imaging studies indicates that people with depression have physical changes in their brains. The significance of these changes is still uncertain but may eventually help pinpoint causes. The naturally occurring brain chemicals called neurotransmitters, which are linked to mood, also may play a role in depression. Hormonal imbalances also could be a culprit.

Depression can be linked to events in your life, such as the death of someone you love, a divorce or job loss. Taking certain medicines, abusing drugs or alcohol, or having other illnesses can also lead to depression. Depression isn't caused by personal weakness, laziness or lack of willpower.

Certain environmental situations, such as stress or breakup of important attachments, also may precipitate depression, especially in vulnerable persons.

Genes. Some studies show that depression is more common in people whose biological family members also have the condition. Researchers are trying to find genes that may be involved in causing depression.