The psychodynamic approach is a form of depth psychology, the goal of this method for the psychotherapist is to open up the unconscious content of the mind in order to treat the psychic tension of the patient. Although this method stems from the psychoanalysis it is a less intensive method. Psychodynamic therapies focus on internal conflicts and unconscious process.
The humanistic/existential approach is connected with the belief that human beings are alone in this world and because of this belief a person may feel a sense of meaningless, this indirect approach offers positive growth, the opportunity for the patient to recognize his/her problems and encourages themselves to create their own values and meanings and to make changes. Humanistic-existential therapies usually focus on what a client is experiencing here and now.
Behavioral is a directive approach based on the principles of classical and operant conditioning, just focusing on behavior and not thoughts. Behavioral therapy also focuses on observational learning. Cognitive mental aspect of behavior is based on the belief that negative feelings are a result of negative thoughts; if a person can change their thoughts then that person can change feelings and their behavior. An approach that combines these two is Cognitive-Behavioral Therapy.