Schizophrenia
Schizophrenia is a mental illness that involves a variety of symptoms. The actual symptoms experienced vary from patient to patient. However, to make the diagnosis it is likely that these will include hallucinations - where you hear, see or smell things which others cannot hear, see or smell - and delusions - where you get ideas about the world which do not match with the views of everyone else - for example - that you are somebody else, or that you are being spoken to by the TV.
Mood disturbance often accompanies acute schizophrenia and can be of any type, such as depression, anxiety, irritability or euphoria.