||Philosophy. the theory that only the self exists, or can be proved to exist.
Solipsism syndrome is a state of mind in which a person begins to feel that everything is a dream and, therefore, is not real.
Solipsism is a philosophical theory that all activity takes place within the mind, and therefore there is no reality outside one’s own mind. As a philosophical theory it is interesting because it is said to be internally consistent and, therefore, cannot be disproven. But as a psychological state, it is highly uncomfortable. The whole of life becomes a long dream from which an individual can never wake up. Even friends are not real, they are a part of the dream and are his own fantasies. A person may feel very lonely and detached, and eventually becomes apathetic and indifferent.
Some environments are conducive to producing solipsism syndrome. This state of mind can be easily produced in an environment where everything is artificial, where everything is like a theatre stage, where every wish can be fulfilled by a push-button, and where there is nothing beyond the theater stage and beyond an individual’s control.
(information from http://en.wikipedia.org/wiki/Solipsism_syndrome)