Write a précis of the passage given below in about one-third of its length. Please do not give any title to it. The précis should be written in your own language.

Mood disorders also called affective disorders, represent a spectrum of mental health illnesses in which prolonged periods of sadness (depression) are on one end and signs of excessive elation (mania) are on the other end. Manifestations of both ends of the spectrum at different times in an individual are termed bipolar disorder.

Major depression manifests as significant depressive episodes without any manic symptoms, often referred to as unipolar depression; it is far more common than mania alone. The lifetime risk for a major depressive disorder is 9% for men and approximately 17% for women. In developed countries, the prevalence of this disorder is around 18%, whereas, in underdeveloped nations, it is around 9%. Major depression may occur at any age, but it most commonly affects middle-aged persons. Elderly individuals who live in health care facilities and individuals affected with a wide range of acute and chronic disease also appear to be at higher risk. Major depression is a disabling condition that causes impairment of basic physical functions, as manifested by sleep disturbances, changes in appetite with associated weight loss or gain, diminished libido, and an inability to experience pleasure (anhedonia). Affective changes include pervasive and persistent low mood, slowed thought processes, low self-esteem, and loss of interest or pleasure in normal activities. Social withdrawal and psychomotor retardation are observed, although agitation can also occur. Patients commonly report somatic symptoms such as fatigue and headache, as well as other nonspecific symptoms. The risk of suicide in the depressed patient is over 25 times that of the general population; factors associated with suicide risk include the degree or longevity of the disorder, male sex, the family history of psychiatric disorder, and the presence of comorbidity. Patients with dysthymic disorder have chronic, less severe depressive symptoms that do not meet the criteria for major depression.

Mania is a period of abnormally and persistently elevated or irritable mood that is sufficiently severe to impair social or occupational functioning. Typical symptoms include euphoria or irritability, grandiosity, decreased need for sleep, increased speed of thought and speech (flight of ideas), and increased goal-directed activity.