People of all ages can develop depression.  It occurs more frequently in females, teenagers, and older adults.  It is not clear why some people develop depression and others do not.  It appears that several factors may contribute to the development of depression. 

Researchers are studying the role of brain chemicals and brain functions.  It appears that abnormal levels of certain brain chemicals, serotonin and norepinephrine, may contribute to depression.  It appears that some people may inherit a genetic predisposition for depression, which increases the risk for developing depression under certain circumstances.

Life events, such as the death of a loved one, unemployment, divorce or relationship breakup, abuse, violence, and neglect may make certain people more vulnerable to depression.  People that are overwhelmed with stress and have low self-esteem, poor positive support systems, or generally negative attitudes may be more likely to develop depression.  Further, depression may be caused by vitamin deficiencies, substance abuse, some medical conditions, and as a side effect of some medications. 

 

Depression can vary in severity.  It may range from mild, moderate, or severe.  Symptoms of depression include feeling sad, hopeless, helpless, or worthless. You may feel anger, self-hate, restlessness, irritability, and inappropriate guilt. You may experience a lack of interest or pleasure in activities that you used to enjoy.  You may withdraw from others and become inactive.  You may feel tired and have a general lack of energy.  You may have problems sleeping.  It may be difficult to fall asleep, stay asleep, or you may oversleep.  It may be difficult to concentrate.  Your appetite may significantly change, and you may lose or gain weight.

In some cases, people may have unusual symptoms, such as hearing voices that are not really there or delusional irrational thoughts.  People with severe depression may think about death a lot or feel suicidal or feel like harming others.  If you experience such symptoms, you should contact emergency medical services, usually 911, or go to the nearest emergency department.

There are several different types of depression including major depression, minor depression, dysthymia, atypical depression, postpartum depression, and seasonal affective disorder.  A major depression involves the presence of more than six symptoms of depression that last for at least two weeks, but the depression lasts for more than six months.  Minor depression consists of less than five depressive symptoms that last less than five weeks.  Dysthymia is a mild form of depression that lasts a long time, usually about two years.  Unusual symptoms, such as hearing things and delusional thoughts, characterize atypical depression.  Postpartum depression is a rare but very serious condition that women may experience after childbirth.  Seasonal affective disorder (SAD) is likely related to the amount of sunlight.  It occurs during the fall and winter seasons and resolves during the spring and summer.
 

It is important to discuss your concerns with a psychiatrist or general medicine doctor if you feel depressed for two weeks or longer.  A psychiatrist can begin to diagnose depression after reviewing your medical history, listening to your symptoms, and by conducting an interview or questionnaire.  A physical examination may be necessary to rule out other medical conditions.  A psychiatrist can also diagnose other psychological conditions that may co-exist with depression.
 

Depression is a very treatable condition.  The type of treatment that you receive depends on several factors, including the cause, severity, and type of depression that you have.  Common treatments for depression are therapy and medications.  Medications may be used on a short-term or long-term basis.