psychology - interactionist approach of schizophrenia

It's the conflict between the biology and environment.
A diathesis-stress model is used.

Schizophrenia is a genetically inherited condition (Well mostly) for an individuals offspring. The theory proposes that parents who have children have a genetic vunerability, remember you are not born with schizophrenia. This vunerability (Biology) is always in conflict with external factors (Environment), and the condition is said to be the byproduct of this confliction. The gene gets switched on by whatever factor influences it, and schizophrenia then develops, this has been researched heavily within twin studies that finds the identical twin is far more likely to develop schizophrenia than non twin siblings. Adoptive children are also less likely to develop than biological relatives. However, about 50% of identical children, the other half doesn't develop the condition, which means there is a strong case for environmental factors to be at work here, triggering these genetic vunerabilities. This is what the model proposes.