Which neurotransmitter is commonly associated with a calming effect on mood?

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

Answer: (C)

The main concept here is how neurotransmitters regulate mood, with serotonin specifically linked to a calming mood. Serotonin helps stabilize emotions, modulate anxiety, and influence sleep and appetite. When serotonin activity is higher, mood tends to feel calmer and more balanced, which is why medications that increase serotonin in the brain are effective for reducing anxiety and improving mood in many people. In contrast, dopamine is more about reward and motivation, glutamate is the primary excitatory messenger involved in fast neural signaling and arousal, and acetylcholine supports learning and attention. While these neurotransmitters influence mood in various ways, none are as closely associated with a calming, mood-stabilizing effect as serotonin.