Depression (mood)

Depression
Lithograph of a person diagnosed with melancholia and strong suicidal tendency in 1892
SpecialtyPsychiatry, psychology
SymptomsLow mood, aversion to activity, loss of interest, loss of feeling pleasure
CausesBrain chemistry, genetics, life events, medical conditions, personality
Risk factorsStigma of mental health disorder
Diagnostic methodPatient Health Questionnaire, Beck Depression Inventory
Differential diagnosisAnxiety, bipolar disorder, borderline personality disorder
PreventionSocial connections, physical activity
TreatmentPsychotherapy, psychopharmacology

Depression is a mental state of low mood and aversion to activity. It affects about 3.5% of the global population, or about 280 million people worldwide, as of 2020. Depression affects a person's thoughts, behavior, feelings, and sense of well-being. The pleasure or joy that a person gets from certain experiences is reduced, and the afflicted person often experiences a loss of motivation or interest in those activities. People with depression may experience sadness, feelings of dejection or hopelessness, difficulty in thinking and concentration, or a significant change in appetite or time spent sleeping; suicidal thoughts can also be experienced.

Depression can have multiple, sometimes overlapping, origins. Depression can be a symptom of some mood disorders, some of which are also commonly called depression, such as major depressive disorder, bipolar disorder and dysthymia. Additionally, depression can be a normal temporary reaction to life events, such as the loss of a loved one. Depression is also a symptom of some physical diseases and a side effect of some drugs and medical treatments.