It can be diagnosed with blood tests, urine screen for drug metabolites, and CT scans (“Schizophrenia” 109). The most efficient way of diagnosing schizophrenia is the observation of an individual’s behavior in a period of time. In the film, John Nash’s diagnosis of schizophrenia, more specifically paranoid schizophrenia, happened when his paranoia took over his professional life and he is forced to be evaluated in a psychiatric hospital. It is there Dr. Rosen observes Nash and discovers that John has suffered for years from visual hallucinations by seeing Charles ‘his roommate at Princeton,’ Marcee ‘Charles’s niece,’ and William Parcher ‘supervisor for soviet threats at the U.S. Department of Defense.’ John also suffered from the delusion that he was helping Parcher by cracking ‘soviet threats to the United States’ through deciphering codes in newspapers and magazines which ultimately lead to his paranoia. Like many other psychiatrists, Dr. Rosen was able to observe John’s behavior, connect it with the known symptoms of paranoid schizophrenia, and helped John to get proper