Final answer:
Schizophrenia may be triggered by a complex interplay of genetic and environmental factors such as disturbed family environments, obstetric complications, and drug use. Brain abnormalities, particularly in the frontal lobes and dopaminergic neurons, also play a key role in the development of the disorder.
Step-by-step explanation:
In regards to what may have triggered John's schizophrenia, multiple factors may have contributed. Schizophrenia is thought to have both a genetic and environmental basis. Genetics play a part, with the risk increasing if a parent has the disorder. Environmental factors can also contribute, such as disturbed family environments, obstetric complications, maternal infections during pregnancy, and drug use like marijuana.
Abnormalities in brain anatomy and functioning are also implicated in schizophrenia. Patients may show enlarged ventricles and reduced gray matter in the frontal lobes of the brain, possibly due to abnormal brain development influenced by genetic and environmental factors. Dopaminergic neurons, which affect dopamine, a neurotransmitter important for motivation and pleasure, are believed to malfunction in schizophrenia, and treatments often involve medications that decrease dopamine transmission.
Learn more about Schizophrenia