Signs & symptoms of psychosis Although psychosis and mental illness affect people in different ways, there are recognised signs and symptoms which people may experience. Not everyone will experience all the symptoms, some people may experience other symptoms. It is important to remember that this behaviour is not deliberate or caused by anything that you or the person you care about have done. The list is not exhaustive but covers the most commonly observed symptoms. Hallucinations : the person can see, hear, feel, smell or taste something that does not exist, as if it were real. Hearing voices is the most common hallucination experienced with schizophrenia.Delusions : the person holds false and often unusual beliefs with unshakeable conviction. For example, someone fears that he or she is being watched or followed by another who wants to control him or her or do him or her harm.Emotional blunting : the person appears to show little emotion or if he or she does express any it may appear out of context, for example crying at a joke.Apathy : the person may become withdrawn, avoiding the company of friends and family and staying in his or her room.Speech difficulties : the person may say very little and rarely initiate a conversation. Or they may speak in a way which will seem muddled and illogical, conveying little meaning.Thought disorders and strange behaviour : the person may think or act in a way that cannot easily be understood. He or she may become uncharacteristically hostile to members of the family.