Depression (mood)

Depression is a mental state of low mood and aversion to activity. It affects more than 280 million people of all ages (about 3.5% of the global population). Depression affects a person's thoughts, behavior, feelings, and sense of well-being. Depressed people often experience loss of motivation or interest in, or reduced pleasure or joy from, experiences that would normally bring them pleasure or joy. Depressed mood is a symptom of some mood disorders such as major depressive disorder and dysthymia; it is a normal temporary reaction to life events, such as the loss of a loved one; and it is also a symptom of some physical diseases and a side effect of some drugs and medical treatments. It may feature sadness, difficulty in thinking and concentration and a significant increase or decrease in appetite and time spent sleeping. People experiencing depression may have feelings of dejection or hopelessness and may experience suicidal thoughts. It can either be short term or long term. Adversity in childhood, such as bereavement, neglect, mental abuse, physical abuse, sexual abuse, or unequal parental treatment of siblings can contribute to depression in adulthood. Childhood physical or sexual abuse in particular significantly correlates with the likelihood of experiencing depression over the survivor's lifetime. Life events and changes that may cause depressed mood include (but are not limited to): childbirth, menopause, financial difficulties, unemployment, stress (such as from work, education, military service, family, living conditions, marriage, etc.), a medical diagnosis (cancer, HIV, diabetes, etc.), bullying, loss of a loved one, natural disasters, social isolation, rape, relationship troubles, jealousy, separation, or catastrophic injury. Adolescents may be especially prone to experiencing a depressed mood following social rejection, peer pressure, or bullying. Depression is associated with low extraversion, and people who have high levels of neuroticism are more likely to experience depressive symptoms and are more likely to receive a diagnosis of a depressive disorder.