I have a friend suffering from depression. He takes anti-depressants to help.
People woth depression may be notably sad, anxious, or empty; they may also feel notably hopeless, helpless, dejected, or worthless.
Yeah I feel sorry for them. It must be tough to feel those emotions.
It is a very difficult thing that can affect a person's thoughts, behavior, feelings, and sense of well-being.
I am glad that there are drugs that also help such as Prozac and Paxil.
Sometimes depression is a normal temporary reaction to life events and drugs are not needed. 
That is true. Sometimes psychotherapy is all that is needed for patients to start feeling better.
Psychotherapy
Psychotherapy is the use of psychological methods, particularly when based on regular personal interaction, to help a person change behavior and overcome problems in desired ways. Psychotherapy aims to improve an individual's well-being and mental health, to resolve or mitigate troublesome behaviors, beliefs, compulsions, thoughts, or emotions, and to improve relationships and social skills. Certain psychotherapies are considered evidence-based for treating some diagnosed mental disorders. Others have been criticized as pseudoscience.
There are over a thousand different psychotherapy techniques,
. Depressed people may also feel sad, anxious, empty, hopeless, worried, helpless, worthless, guilty, irritable, hurt, or restless. They may lose interest in activities that once were pleasurable, experience loss of appetite or overeating, have problems concentrating, remembering details, or making decisions, and may contemplate or attempt suicide. Insomnia, excessive sleeping, fatigue, loss of energy, or aches, pains, or digestive problems that are resistant to treatment may also be present.
About one in six people