The Biological Causes of Schizophrenia
The most important role of biology is to help us better understand ourselves. One aspect of understanding ourselves is knowing why things go wrong with our bodies and biology can help us do that. Schizophrenia is a very problematic disease in our world today. It is a mental disease which causes paranoia, hallucenations, and disassociation from the real world and numerous other problems. The biological causes of schizophrenia are both controversial and important to understand as one million to two million people have long-term schizophrenia, and 100,000-200,000 people become schizophrenic every year. Fifty percent of people in hospital psychiatric care have schizophrenia (Boyle 2002). The cause of schizophrenia is not known. However, both nonbiological (psychological) and biological (familial, chemical imbalances in the brain) factors are thought to be involved. As technology allows disorders of the brain to be further defined, biological causes are becoming better understood.
These biological issues will be further discussed as this is my focus. Genetic predisposition, infectious agents, allergies, and disturbances in metabolism are biological issues that have been studied in the cause of schizophrenia.
Numerous studies have established the familial aggregation of schizophrenia (Goeff 2002). This shows that schizophrenia is hereditary. This is frightening as it makes schizophrenia even harder to cure. Little is known about how genetic liability to schizophrenia is transmitted, although statistical models suggest that transmission is probably not due solely to a single major gene. Schizophrenia is clearly a complex disorder in that gene carriers need not manifest the illness (incomplete penetrance), affected individuals need not have the gene (environmental forms of phenocopies), diagnostic uncertainties cannot be avoided, and different families may carry different susceptibility genes (genetic heterogeneity). Therefore, segregation or linkage analyses are far more difficult to perform with schizophrenia than with Mendelian genetic disorders.