Final answer:
Individuals with schizophrenia typically have excess dopamine activity in the brain, which contributes to the disorder's symptoms like hallucinations and delusions.
Step-by-step explanation:
People with schizophrenia are likely to have excess dopamine activity, one of the several factors involved in this complex mental disorder. Antipsychotic medications, which are commonly used to treat schizophrenia, function as antagonists to dopamine receptors to curb the overactivity. This action directly addresses the positive symptoms of schizophrenia, such as hallucinations and delusions, by limiting dopamine's effects in the brain. However, it's important to note that individuals with schizophrenia may actually have other physiological differences, such as enlarged ventricles or reduced frontal lobe activity rather than increased.