One biological explanation for Schizophrenia is the Dopamine hypothesis. This proposes the idea that here is an excess amount of D2 receptors that causes the brain to release more dopamine as it believes more is needed. In turn, an excess amount of dopamine firing and binding takes place within the mesolimbic pathway of the brain. The increase in this specific hormone causes the positive symptoms associated with schizophrenia. For example, hallucinations and delusions of grandeur. This has been proven in studies where drugs that decrease dopamine levels lead to a decrease in positive symptoms in Schizophrenic people.