The causes of Schizophrenia is mainly a biological predisposition, than means inheritation of certain genes ... then comes the environment that a person is exposed to, here are some types of Schizophrenia :

- Paranoid schizophrenia : These persons are very suspicious of others and often have grand schemes of persecution at the root of their behavior. Halluciations, and more frequently delusions, are a prominent and common part of the illness.

- Disorganized schizophrenia (Hebephrenic Schizophrenia) : In this case the person is verbally incoherent and may have moods and emotions that are not appropriate to the situation. Hallucinations are not usually present.

- Catatonic schizophrenia : In this case, the person is extremely withdrawn, negative and isolated, and has marked psychomotor disturbances.

- Residual schizophrenia : In this case the person is not currently suffering from delusions, hallucinations, or disorganized speech and behavior, but lacks motivation and interest in day-to-day living.

- Schizoaffective disorder : These people have symptoms of schizophrenia as well as mood disorder such as major depression, bipolar mania, or mixed mania.

- Undifferentiated Schizophrenia : Conditions meeting the general diagnostic criteria for schizophrenia but not conforming to any of the above subtypes, or exhibiting the features of more than one of them without a clear predominance of a particular set of diagnostic characteristics.