Depression is a condition which causes feelings of discouragement, sadness, hopelessness, demotivation and lack of interest in life in general. It is normal to experience these feelings from time to time, but when such feelings last for more than two weeks and when the feelings interfere with daily activities such as taking care of family, spending time with friends, or going to work or school, it is likely that you need to seek assistance in dealing with this depressive mood state.