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. …