All diagnosed schizophrenics share certain afflictions, such as hallucinations and incoherence lasting for a week or more. The American Psychiatric Association recognizes five sub types of schizophrenia, one of which is the catatonic type. Catatonic schizophrenics often don’t speak and they may assume rigid postures for hours or days. This type of schizophrenia is marked by an emotional numbness or negativism that flattens motivation and can halt speech and limit movement. Paranoid schizophrenics are preoccupied with delusions and haunted by auditory hallucinations.