Often depression develops in response to illness, stress or losses of various types. The other major type of depression, endogenous depression, occurs for no obvious cause, and is due to changes in various brain chemicals, the neuro-transmitters. Sometimes people with this biological type of depression also experience periods of elevated mood, or highs. When both highs and depressed periods of mood occur, the mood disorder is termed a bipolar affective disorder. All men and women are vulnerable to depression.
Many groups are at particular risk.
Symptoms in children may be the same as adults. Like other illnesses, depression requires specific and specialised treatment. These may include individual or group therapy. Sometimes these are given specific names e.g. cognitive therapy, rational emotive therapy. If moderate in severity, a depressive illness requires treatment with antidepressant medication.