Depression: a morbid sadness, dejection, or melancholy.
Depression affects twice as many women as men, major depression is characterized by at least one 2 week episode of depressed mood.  Incidence is also high among patients hospitalized with medical illness.

There is multiple cause of depression and not all are completely understood, most are controversial.  Research suggests possible genetic, familial, biochemical, physical, psychological, and social causes.  Studies shows that with many patients, the history identifies a specific personal loss or severe stress that probably interacts with a person's predisposition to major depression.

Symptoms:

Major depression is a relatively persistent and prominent dysphoric mood, with loss of interest in usual activities and pastimes, which may shift periodically to anger or anxiety.

• Appetite disturbance - weight loss without dieting, or significant appetite or weight gain

• Sleep disturbance - insomnia or hypersomnia

• Fatigue - energy loss

• Psychomotor agitation - hyperactive or slow inactive behavior

• Loss of interest - possible decreased sex drive, or loss of pleasure in activities

• Feelings of worthlessness - excessive guilt and self reproach

• Difficulty in concentration, decision making, or thinking

• Recurrent suicidal thoughts, suicide attempts, or wishing death over life

Treatment:

Psychotherapy drugs and or Antidepressant therapy (combination of the two has been known to work well together)

Somatic therapy - aim to relieve depressive symptoms

Sedative - if patient has insomnia

Electroconvulsive therapy (ECT) or Electric shock treatment - use for severely depressed or suicidal patients who do not respond to other treatments.

Depression is very difficult to treat, especially in children, adolescents, elderly, and those with a history of chronic disease, but treatment has become more effective.