Risk factors of schizophrenia include multiple genetic and environmental risk factors. The prevailing model of schizophrenia is that of a neurodevelopmental disorder with no precise boundary, or single cause, and is thought to develop from complex gene–environment interactions with involved vulnerability factors. The interactions of these risk factors are complicated, as numerous and diverse insults from conception to adulthood can be involved. The combination of genetic and environmental factors leads to deficits in the neural circuits that affect sensory input and cognitive functions.