Often this longitudinal view is required to make the diagnosis confidently. The advent of the modern classification systems has improved the reliability of the diagnosis. Sometimes more than one voice talk to each other about the patient. Hearing voices is not just characterisctic of schizophrenia. It is also seen in dissociative, affective and organic states.
Visual hallucinations are less common.
Some object or person who is not there is definitely perceived as present in the presence of a clear consciousness. Tactile hallucinations are the least common. Examples are the experience of being touched by someone or that something is creeping underneath the skin. Delusions are false or irrational beliefs that are firmly held despite obvious evidence to the contrary. Most common are persecutory, grandiose and religious delusions.