Depression (mood)

In the fields of psychology and psychiatry, the terms depression or depressed refer to both expected and pathologically chronic or severe levels of sadness, perceived helplessness, disinterest, and other related emotions and behaviours. The Diagnostic and Statistical Manual of Mental Disorders (DSM) states that a depressed mood is often reported as being: "depressed, sad, hopeless, discouraged, or 'down in the dumps'." In traditional colloquy, "depressed" is often synonymous with "sad," but both clinical and non-clinical depression can also refer to a conglomeration of more than one feeling. Such a mixture can include (but is not limited to) anger, fear, anxiety, despair, guilt, apathy, and/or grief, in addition to what many people would describe as typical "sadness."

Biology

Biological influences of depression are varied, but can include heredity, hormones, life problems, seasonal factors, stress, illness, neurotransmitter malfunction, long-term exposure to dampness and mold and to aerosol exposure. There are also strong links between long term sleep difficulties with depression. Up to 90% of patients with depression are found to have sleep difficulties.

Depression as mechanism of adaptation

While a depressed mood is usually referred to (and perceived) as negative, it can sometimes be subtly beneficial in helping a person adapt to circumstance. For example, physical illness, such as influenza, can lead to feelings of psychological malaise and depression that seem, at first, only to compound an already unpleasant situation. However, the experience of depression, or feeling "down," often results in physical inertia, which leads to the compulsion to rest. The fleeting helplessness and immobility of the physically ill may also serve to elicit care from others.

From an evolutionary standpoint, some argue that depression could be at least partially related to atavistic fears that were originally based on real dangers. Paul Keedwell, in his book, How Sadness Survived: The Evolutionary Basis of Depression, suggests that, because "social support and interdependence were important features of the [human] ancestral environment," "the [peer] group could have offered extra help to the depressed person until the condition resolved." Further, "...a depressed person may change the attitudes of other people around him, making them more sympathetic to his needs and therefore giving him a long term [social or reproductive] advantage.

Temporary depression, psychologist Thomas Moore, Ph.D., suggests, can, in some cases, not only "...provide a rest from the hyperactivity of the good times...," but can also be assigned value in the overall spectrum of human experience, and might enrich the ways in which members of a community relate to, and support, one another. In some cases, Moore says, "dark times [can] leave their mark and make you a person of insight and compassion."

Psychological disorders with depression

Episodes of depressed mood are a core feature of the following psychological disorders, as specified by the DSM-IV:

• Major depressive disorder
• Dysthymia
• Bipolar disorder
• Cyclothymia
• Schizoaffective disorder
• Seasonal affective disorder
• Adjustment disorder with depressed mood

See also

• Grief
• Emotion
• Clinical depression
• Depression and natural therapies

References

External links

• About the Brain – Includes definitions relating to depression
• beyondblue – The Australian National Depression Initiative
• Black Dog Institute – Depression and Bipolar Disorder Information Australia
• Depression at WebMD - Drug and treatment information for depression.
• Depression Research News at ScienceDaily
• National Alliance on Mental Illness – Depression support, advocacy, and education
• National Depressive and Manic Depressive Association - National Depressive and Manic Depressive Association
• Stanford Depression Research Clinic
• Substance Abuse and Mental Health Services (SAMHSA) – United States Department of Health and Human Services (HHS)