In major depressive disorder, which neurotransmitters are reported as decreased?

In major depressive disorder, which neurotransmitters are reported as decreased?

• A. Serotonin, dopamine, and norepinephrine
• B. Only serotonin
• C. Only norepinephrine
• D. GABA and glutamate

Answer: (A)

Depression is linked to reduced activity of monoamine neurotransmitters in brain circuits that regulate mood, motivation, and arousal. In major depressive disorder, serotonin, norepinephrine, and dopamine are typically decreased. Serotonin helps stabilize mood, appetite, and sleep; norepinephrine influences alertness and the stress response; dopamine governs reward and motivation. When these systems are underactive, symptoms such as low mood, anhedonia, fatigue, and cognitive slowing emerge. This pattern also explains why many antidepressants aim to boost these monoamines. While GABA and glutamate are involved in depression and show dysregulated signaling, they are not simply decreased at baseline in the same way as the monoamines. So, the combination of decreased serotonin, norepinephrine, and dopamine best fits the typical neurotransmitter changes described in major depressive disorder.

Depression is linked to reduced activity of monoamine neurotransmitters in brain circuits that regulate mood, motivation, and arousal. In major depressive disorder, serotonin, norepinephrine, and dopamine are typically decreased. Serotonin helps stabilize mood, appetite, and sleep; norepinephrine influences alertness and the stress response; dopamine governs reward and motivation. When these systems are underactive, symptoms such as low mood, anhedonia, fatigue, and cognitive slowing emerge. This pattern also explains why many antidepressants aim to boost these monoamines. While GABA and glutamate are involved in depression and show dysregulated signaling, they are not simply decreased at baseline in the same way as the monoamines. So, the combination of decreased serotonin, norepinephrine, and dopamine best fits the typical neurotransmitter changes described in major depressive disorder.