depression

n.

1) a mental state characterized by excessive sadness.

2) a mood disorder characterized by the pervasive and persistent presence of core and somatic symptoms on most days for at least 2 weeks. Core symptoms include low mood and loss or impairment of motivation, energy, interest, and enjoyment. Somatic symptoms include impaired memory and concentration, loss of appetite and libido, insomnia, early morning wakening (more than 2 hours earlier than normal), physical and mental activity that is either agitated and restless or slow and retarded, and a diurnal variation of mood (usually patients feel particularly depressed in the mornings). Additional symptoms include automatic negative thoughts, pessimistic views of oneself, the future, and the present (Beck's triad of depression), suicidal ideation, tearfulness, alexithymia, and a poor frustration tolerance. Depression may or may not be triggered by stressful events or trauma. Risk factors include genetic and social elements (e.g. poverty, lack of confidants, substance abuse) and psychological elements (e.g. the presence of personality disorder, a history of abuse or dysthymia). Treatment is with antidepressant drugs, cognitive behavioural therapy, and/or psychotherapy. Severe cases may need electroconvulsive therapy. The course of the illness can be a single episode or recurrent episodes, or it may become chronic.

Derivatives:

depressiondepressive adj.