This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Schizophrenia and other psychotic disorders, Subject name: Psychiatry
Biochemical abnormalities in schizophenia 
Select and explain. 
A. Increased dopamine, B. Increased dopamine and increased serotonin, C. Decreased dopamine, D. Decreased dopamine and decreased serotonin
B: Increased dopamine and increased serotonin
Answer: B: Increased dopamine and increased serotonin 
Explanation: Biochemical Theories Schizophrenia is presently thought to be probably due to a functional increase of dopamine at the postsynaptic receptor, though other neurotransmitters such as serotonin (especially 5-HT2 receptors), GABA and acetylcholine are also presumably involved. Ref: A Sho Textbook of Psychiatry, Niraj Ahuja, 7th Edition, pg. no. 63