This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
Transmitters mainly involved in OCN is 
Select and explain. 
A. GABA, B. NE, C. Dopamine, D. Serotonin
D: Serotonin
Answer: D: Serotonin 
Explanation: D i.e. SerotoninOCN involves Serotonin (5-HT) system, so fluoxetine (SSRI) is DOC.DiseaseRelated NeurotransmitterAlzheimer'sdisease- Acetyl cholineQ & Nor epinephrine are hypoactive- So anticholine-esterase - TacrineQ is used in treatment.DepressionNorepinephrine, Serotonin (5-HT)Q & Dopamine are reducedOCNSerotonin (5 117)(2SchizophreniaDopamine, Serotonin & Norepinephrine are ted(2