Biological factors, genetic traits, environmental influences, childhood development and life events are all thought to be causes of major depression episodes. However, the underlying root cause is usually a combination of many factors.

Symptoms

A person suffering from a major depression will exhibit signs of agitation, difficulty in concentration, fatigue, sense of hopelessness, low self-esteem, self-blaming, inactivity and withdrawal.

Diagnosis

A patient who is experiencing symptoms of depression and seeks professional help will first undergo a psychological evaluation, which may include the Beck's Depression Scale Inventory (BDI). The BDI is a series of questions designed to determine the extent, seriousness and level of depression.

Causes

According to the National Institute of Mental Health, research has determined that depressive episodes are disorders of the brain. Magnetic resonance imaging (MRI) shows that the brains of patients suffering from depression are different from those are not.

Genetic Impact

Some depression disorders show a genetic link, according to the National Institute of Mental Health. Different genes acting together with other biological and environmental factors can increase the risk of depression.

Women and Depression

The National Institute of Mental Health reports that women experience depression at greater levels than men. Hormonal changes during and after pregnancy coupled with the responsibilities of both home and work can cause major depression in some women.

Source:

National Institutes of Health: Major Depression

All About Depression: Major Depressive Disorder

National Institute of Mental Health: Depression

More Information:

All-On-Depression-Help.com: Beck's Depression Scale Inventory

Psychology Information Online