Which neurotransmitters are chiefly implicated in mood disorders?

• A. Norepinephrine and Serotonin
• B. Dopamine and Acetylcholine
• C. GABA and Glutamate
• D. Epinephrine and Endorphins

Answer: (A)

Mood regulation in mood disorders is most closely tied to monoamine neurotransmitters, especially serotonin and norepinephrine. Pharmacologic evidence supports this: antidepressants that increase serotonin and/or norepinephrine in the synaptic cleft—such as SSRIs, SNRIs, and many older antidepressants—tend to improve mood. Serotonin helps modulate mood, anxiety, and social behavior, while norepinephrine influences arousal, alertness, and stress responses; when either system is out of balance, mood symptoms often arise.

Dopamine and acetylcholine have important roles in motivation, reward, cognition, and autonomic functions, and while dopamine can affect mood features, it is not the primary regulator of mood disorders. GABA and glutamate are more about neuronal excitation and inhibition and anxiety regulation, not the chief drivers of mood disorders. Epinephrine and endorphins play roles in stress responses and reward/pain pathways but are not the central neurotransmitters linked to mood disorder pathophysiology.

So, the combination of norepinephrine and serotonin is the best-supported link to mood disorders.