Which statement about depression neurotransmitters is true?

Which statement about depression neurotransmitters is true?

• A. Serotonin, dopamine, and norepinephrine are decreased
• B. Only serotonin is decreased
• C. Dopamine is increased
• D. GABA is decreased only

Answer: (A)

Depression is tied to reduced activity of monoamine neurotransmitters in mood-regulating brain circuits. In many patients with major depressive disorder, levels of serotonin, norepinephrine, and dopamine are decreased, which helps explain symptoms like low mood, lack of energy, and anhedonia. This is why treatments that boost these transmitters—SSRIs raising serotonin, SNRIs raising serotonin and norepinephrine, bupropion increasing dopamine and norepinephrine, and MAO inhibitors preventing breakdown—are effective. While GABA and glutamate may also be involved in mood regulation, the classic pharmacologic understanding centers on decreased monoamines, making the statement about all three being decreased the best fit. The other options don’t align with this widely taught pattern.

Depression is tied to reduced activity of monoamine neurotransmitters in mood-regulating brain circuits. In many patients with major depressive disorder, levels of serotonin, norepinephrine, and dopamine are decreased, which helps explain symptoms like low mood, lack of energy, and anhedonia. This is why treatments that boost these transmitters—SSRIs raising serotonin, SNRIs raising serotonin and norepinephrine, bupropion increasing dopamine and norepinephrine, and MAO inhibitors preventing breakdown—are effective. While GABA and glutamate may also be involved in mood regulation, the classic pharmacologic understanding centers on decreased monoamines, making the statement about all three being decreased the best fit. The other options don’t align with this widely taught pattern.