CBT (or Cognitive Behavioral Therapy) is a therapeutic treatment approach that is based on the principles of cognitive behavioral theory. The theory teaches that thoughts influence the way people feel and behave so if a person has negative thoughts they will tend to have negative beliefs about themselves, others (or the world around them), and about their future. The trouble with having a negative belief system is that people can begin to develop problems such as depression, anxiety, or low self-esteem because they expect negative outcomes and feel unable to do anything to control these negative outcomes from happening to them. CBT teaches people that if they identify their own negative thoughts and beliefs and learn to replace them with more positive alternative thoughts, they will not only be able to manage outcomes in their life better, but they will tend to feel better overall. CBT can be self-taught, but is best delivered through therapy or counseling sessions with a mental health professional.