This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
In depression , there is deficiency of: 
Select and explain. 
A. 5-HT, B. Acetylcholine, C. Dopamine, D. GABA
A: 5-HT
Answer: A: 5-HT 
Explanation: Ref: Katzung 14th ed. Monoamines like serotonin and nor-adrenaline are deficient in depressive patients, therefore reuptake inhibitors of these monoamines are used for treatment of depression.