The word depression is used in many different ways. People feel sad or blue when bad things happen. However, everyday “blues” or sadness is not a depressive disorder. We all may have a short-term depressed mood, but we cope and soon recover without treatment. A major depressive disorder lasts for at least two weeks and affects a person’s ability to work, to carry out usual daily activities, and to have satisfying personal relationships.
The median age of onset is 32 years, meaning that half the people who will have an episode will have had their first episode by this age. Depression often co-occurs with anxiety or substance use disorders. Depression is more common in females than in males. Once a person has had an occurrence of depression, they are prone to additional episodes.