New genetic research indicates that the clinical psychiatric symptoms that lead to a diagnosis of schizophrenia are caused by eight different types of gene cluster groups. The range, combinations, and severity of clinical symptoms associated with schizophrenia—hallucinations, delusions disorganized speech and behavior, lack of initiative, problems organizing thoughts, or lack of connection between emotions and thoughts—are linked to gene clusters in specific genetic networks that affect neural development, neurotrophic functions, neurotransmission, and neuronal function. Schizophrenia is not a single psychiatric disorder; rather schizophrenia is a heterogeneous group of eight heritable disorders that cause clinical syndromes varying in symptoms . . .