This theory developed by Sigmund Freud is the most known theory for development of human beings. Freud describes the stages in which an individual passes from birth to puberty and on. He describes five stages in which all normal human beings go through and in case of proper attention while passing through the stages one can develop abnormal behavior (Sim 45).
Oral stage is the first stage from birth to 18 month. It is marked by oral pressure or sucking. In case of too much or little gratification in this stage an individual may develop oral gratification and engage in much smoking, taking alcohol, over eating and nail biting. Anal stage is the second stage from 18 month to three years and is marked by pleasure of retaining and eliminating feces. Fixation in this stage can make individual to depend on others and lack cleanliness. Phallic is the third stage from three to six years and is marked by pleasure in genitals. In this stage a boy has sexual desires to his mother and girl to father. Fixation in this stage can lead to sexual deviance. Latency is the fourth stage from six years to puberty and is marked by interaction and exchange of ideas in both sexes. The final stage is called genital and starts from puberty. Children are directed to their opposite sex peers and find to certify their sexual needs (ALLPsycho p5).
Depression is a disorder which has the following symptoms, feeling sad for long time like weeks or month, feeling of hopelessness, not enjoying things which one enjoyed in past and lack of energy. A depressed person can not get moving and has no progress in life but a normal person is health and gets moving. Depression can be treated by psychiatry through psychotherapy (John, 1, p3).