Depression is a mood disorder that causes a persistent feeling of sadness and loss of interest. and it become major depressive disorder, when it affects how you feel, think and behave and can lead to a variety of emotional and physical problems. You may have trouble doing normal day-to-day activities, and sometimes you may feel as if life isn t worth living. the cause is actually unknown, however, there are several factors that maybe involved in depression, the following are: 1. Biological differences. 2. the Neurotransmitters that are naturally occurring brain chemicals that likely play a role in depression. 3. Hormones. Changes in the body s balance of hormones may be involved in causing or triggering depression. 4. genetics. Being normal again is very difficult if you suffer from this disorder. because in every aspect it needs to be treated. however, if you feel like there is no amount of cure or medicine already that could treat you. i guess the best solution for that is to Pray and ask God for help. for God says on His word in Matthew 11:28 Come to me, all you who are weary and burdened, and I will give you rest. He is the great physician, the great healer..