Definition of Depression

A mental state characterized by a pessimistic sense of inadequacy and a despondent lack of activity

Sad feelings of gloom and inadequacy

Depressive disorder: a state of depression and anhedonia so severe as to require clinical intervention

In everyday language "depression" refers to any downturn in mood, which may be relatively transitory and perhaps due to something trivial. This is differentiated from Clinical depression which is marked by symptoms that last two weeks or more and are so severe that they interfere with daily living.
A mental state of depressed mood characterized by feelings of sadness, despair and discouragement. Depression ranges from normal feelings of the blues through dysthymia to major depression. It in many ways resembles the grief and mourning that follow bereavement, there are often feelings of low self esteem, guilt and self reproach, withdrawal from interpersonal contact and physical symptoms such as eating and sleep disturbances.

A depressive disorder characterized by extreme feelings of sadness, lack of self-worth, and dejection.

Not just temporary or situational sadness, but a persistent and pervasive feeling of sadness or hopelessness that is often associated with weight loss (or gain), sleep disturbances, constipation, disturbances of sexual function, and feelings of guilt or self-blame.

Mental state characterized by feelings of sadness, loneliness, despair, low self-esteem, and self-reproach; accompanying signs include psychomotor retardation or at times agitation, withdrawal from interpersonal contact, and vegetative symptoms such as insomnia and loss of appetite. The term refers either to a mood that is so characterized or to a mood disorder.

A lifestyle whose structure prevents growth of the personality.

Depression is a state of low mood that is described differently by people who experience it. Commonly described are feelings of sadness, despair, emptiness, or loss of interest or pleasure in nearly all things. Depression can also be experienced in other disorders, such as bipolar disorder (manic-depressive disorder).

When used to describe a mood, depression refers to what may be normal feelings of sadness, despair and discouragement. More serious depression may be a symptom of a variety of physical and mental disorders, a syndrome of associated symptoms secondary to an underlying disorder, or it may itself be a specific mental disorder. ...

A mental disorder marked by altered mood, this may occur daily with the addition of diminished interest or pleasure in most or all activities. Symptoms can be as follows: poor appetite or weight loss, or weight gain, insomnia or hypersomnia, feelings of hopelessness, worthlessness or inappropriate guilt, difficulties with concentration and thinking, and recurrent thoughts of death or suicidal ideations.

Is a common condition. The main symptoms are feeling low, sleep problems, loss of appetite, concentration and energy. There are a number of treatments that can help. See our leaflets on Depression, Depression in Older Adults, and Physical Illness and Mental Health or our factsheet on antidepressants for further information.

A state of sadness marked by inactivity and inability to concentrate: reduction of the functional activity of the body.
is a major disorder that can begin at any age. Major depression may be characterized by a depressed mood most of each day, lack of pleasure in most activities, thoughts of suicide, insomnia, and feelings of worthlessness or guilt.

A state characterized by depressed mood, decreased energy, reduced interest in sex, suppressed appetite, and too much sleep or sleeplessness. Depression is common in people with HIV infection; it often responds well to treatment.
A mood described as feeling dejected and sad with a lowering of functional activity. A depressive disorder usually includes appetite and sleep disturbances, difficulty concentrating, and suicidal ideation.

A medical condition leading to intense feelings of sadness or despair.