It is a feeling of constant sadness. It affects sleep, appetite and concentration. It is predicted that by 2020 depression will be the second leading cause of disease burden. Depression costs the UK 8 billion annually. There is a higher incidence of depression among women than men.
Depression also affects children.
The metabolism of the brain is affected and the levels of certain chemicals altered. Genetics and family history play a role as well as life events. Taking medication usually shortens the duration of depressive episodes. Some people only experience one episode of depression while others can suffer from long bouts of the illness with frequent relapses. Antidepressants are used to address the chemical imbalance in the brain.