Depression affects a large amount of America's population. Sufferers of it experience symptoms that have a debilitating affect on their lives, such as chronic sadness and lack of motivation. Depression is rooted in a specific thought process that starts to become increasingly prevalent, and eventually takes over. One may focus on only what seems dissatisfactory in their surroundings, or what could make their existence meaningless. Therefore, having depression is a lot more complicated than simply "feeling blue".
If depression is related to a thought process, then breaking it is the key to relieving one of their depression. Chances are, the client didn't always feel that way. By tapping into the memories and feelings one felt while being able to get past a difficult point in their lives, one can program the brain to feel optimistic about what one is going through in the present, and to associate happy feelings with the future. Breaking down the brain's preconceptions of how things are is very important as well. If the client feels as though everything she does is futile, then perhaps she should think of a time when she did something and succeeded. By finding exceptions in one's thought process, one can change the entire thought process.
Thus, feelings of depression can often be cured by a simple shift in perception. A shift in perception can be achieved by putting a client in a state of hypnosis, a state in which they are unburdened by anxieties and the noises of their other thoughts. This state can often be described as a moment of "mental clarity", one in which the client has a greater capacity to understand themselves and what goes on around them. Such introspection is key to the dissection and resolution of one's problem.