In schizophrenia, which neurotransmitter is typically increased?

• A. Dopamine
• B. Serotonin
• C. GABA
• D. Glutamate

Answer: (A)

Schizophrenia involves excess dopamine signaling in certain brain circuits, especially the mesolimbic pathway. This increased dopamine activity is linked to the positive symptoms like hallucinations and delusions, because that circuit helps assign salience to stimuli and can overreact to normal stimuli. Antipsychotic meds work mainly by blocking D2 receptors in this pathway, which helps dampen those symptoms. It’s also useful to remember that dopamine can be reduced in the mesocortical pathway, which may contribute to negative and cognitive symptoms, illustrating how dopamine’s role varies by brain region. While other neurotransmitters such as serotonin, glutamate, and GABA participate in schizophrenia and influence treatment effects, the neurotransmitter most characteristically increased in this condition is dopamine.