How can you know someone has schizophrenia?

An assessment: There is no way of knowing that someone has schizophrenia without a comprehensive psychiatric assessment. All of the symptoms of the disorder can be caused by other psychiatric disorders, or neurologic or medical disorders. Schizophrenia is a diagnosis that is usually made after all of those other possibilities are ruled out.

It may be difficult: It may not be particularly apparent for an observer to know whether or not someone has schizophrenia. With the most common type-paranoid schizophrenia-the person may not say anything or really do anything which would cause others to think there is a problem. Often, only after careful investigation and an evaluation by a psychiatrist will the diagnosis of schizophrenia be able to be made.

Hallucinations: By definition, schizophrenia is about psychosis. Psychosis means the patient is getting external stimuli from the environment through one or more of his or her five senses, that does not objectively exist. In other words there are auditory,visual, olfactory, gustatory, and tactile hallucinations that can be experienced by the patient. Auditory hallucinations, however, are the most common.