Which neurotransmitter is primarily linked to mood regulation?

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

Answer: (B)

Mood regulation is most closely tied to serotonin, a monoamine neurotransmitter produced in the brainstem and sent to widespread regions involved in emotion, such as the limbic system and prefrontal cortex. Serotonin helps stabilize mood, influence feelings of well-being, and modulate arousal, sleep, and appetite. When serotonin signaling is reduced, mood can become more negative, which is a reason why medications that increase serotonin availability in the synapse (like SSRIs) are effective for treating depression and anxiety.

Dopamine is more about reward, motivation, and reinforcement, so it shapes how we experience pleasure and drive, rather than mood regulation in a broad sense. Acetylcholine is crucial for attention, learning, and memory, not primarily for mood. Endorphins act as natural painkillers and contribute to sensations of pleasure, but they aren’t the main system governing mood regulation.