Causes+of+Depression

Causes of depression (depressive disorders).
Depression, like other mental illnesses, is probably caused by a combination of biological, environmental, and social factors, but the exact causes are not yet known. For years, scientists thought that low levels of certain neurotransmitters (such as serotonin, dopamine, or norepinephrine) in the brain caused depression. However, scientists now believe that the interplay of factors leading to depression is much more complex. Genetic causes have been suggested from family studies that have shown that between 20 and 50 percent of children and adolescents with depression have a family history of depression and that children of depressed parents are more than three times as likely as children with nondepressed parents to experience a depressive disorder. Abnormal endocrine function, specifically of the **hypothalamus** or **pituitary**, may play a role in causing depression. Other **risk factors** for depressive disorders in youths include Depression, like other mental illnesses, is probably caused by a combination of biological, environmental, and social factors, but the exact causes are not yet known. Scientists have studied changes in the brain associated with depressive disorders. Imaging studies using PET have shown that brain activity in certain areas is substantially decreased in a depressed individual whereas activity in other brain regions is increased compared with the same individual after successful treatment.13 PET imaging has also shown that depressed patients have lower neurotransmitter receptor binding potential in some areas of the brain.48 Scientists looking at changes in the brains of bipolar patients found decreases in the size of the cerebellum (the part of the brain that regulates balance and controlled movements), changes in the metabolism of some chemical compounds, and a decrease in the activity of specific brain regions (prefrontal cortex) during the depression phase.
 * stress,
 * cigarette smoking,
 * loss of a parent,
 * the breakup of a romantic relationship,
 * attention disorders,
 * learning disorders,
 * abuse,
 * neglect, and
 * other trauma including experiencing a natural disaster.22

http://science.education.nih.gov/Supplements/Nih5/Mental/guide/info-mental-c.htm