schizophreniform disorder

In mental disorders, Brief Psychotic Disorder, Schizoaffective Disorder, Schizophreniform Disorder, Schizophrenia, and Delusional Disorder can cause delusions. In some cases, severe mania or depression can cause delusions.

Psychosis in schizophrenia and perhaps schizophreniform disorder appears to be related to abnormalities in the structure and chemistry of the brain, and appears to have strong genetic links

There are many mental illnesses where you may hallucinate. They include schizophrenia, schizoaffective disorder, schizophreniform disorder, shared psychotic disorder, brief psychotic disorder, substance-induced psychotic disorder, bipolar disorder, major depression with psychotic features, delirium, and dementia. However, when someone talks about a mental illness in which you "hear things" or "see things" it will usually be schizophrenia.

Opinions are divided on that. Some clinicians say that mild cases of schizophrenia are possible, and are in fact true in cases of paranoid, schizoid, and schizotypal personality disorders. Others say that schizophrenia is schizophrenia, and you cannot have a milder form of it.