Always low mood may be the following reasons: First, if low mood has lasted for a long time, and always happy, reluctant to do things, low self-esteem, self-blame and even pessimism, negative, it may be caused by depression as a mental illness. Second, the pressure is relatively large and other psychosocial factors caused by the face of work pressure, pressure to go to school or family tension, and a lot of conflict with other people, and there is no way to solve a short period of time, there is always so much pressure is easy to make people unable to happy, the mood is always very low. Third, some people’s character defects caused by, in particular, some people have low self-esteem, a particularly low opinion of themselves, there is no way to accept themselves well, and sensitive love to drill, these character problems are easy to make their own mood down, no happy things, less interest, and no good friends, it is easy to be depressed every day.