Answer:
The correct answer is : Dopamine.
Step-by-step explanation:
The classical dopamine hypothesis states that the excess of dopamine is one of the main causes of Schizophrenia.
Over the years, scientists have developed certain medications that are currently being used by doctors to treat schizophrenia.
These meds are called antipsychotics.
Antipsychotics prove to be effective while treating certain symptoms of schizophrenia.
All antipsychotics are antagonists of the dopamine receptor, thus they lower the dopamine levels of the patient.
This is why there exists the widely held belief that schizophrenia is related to excessive activity of the neurotransmitter dopamine in the brain.