Why is schizophrenia considered to be multifactorially inherited?

Schizophrenia has no single cause. A combination of genes from both parents plays a role. So do unknown environmental factors. Experts believe that a child has to inherit a chemical imbalance in the brain to develop it.

Schizophrenia is considered to be multifactorially inherited. Multifactorial inheritance means that "many factors" are involved. The factors are usually both genetic and environmental, where a combination of genes from both parents, in addition to unknown environmental factors, produce the trait or condition.