Which type of antidepressant is correctly matched with its primary neurotransmitter action?

• A. Serotonin-norepinephrine reuptake inhibitors (SNRIs) decrease norepinephrine levels
• B. Selective serotonin reuptake inhibitors (SSRIs) increase the availability of serotonin in the synaptic cleft
• C. Tricyclic antidepressants (TCAs) primarily enhance gamma-aminobutyric acid (GABA) transmission
• D. Monoamine oxidase inhibitors (MAOIs) block dopamine reuptake

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the primary neurotransmitter actions associated with each class of antidepressants. This involves knowing which neurotransmitters are affected and how their levels or activity are altered in the brain.
2. Step 2: Review the mechanism of Serotonin-norepinephrine reuptake inhibitors (SNRIs). These drugs block the reuptake of both serotonin and norepinephrine, thereby increasing their levels in the synaptic cleft, rather than decreasing norepinephrine levels.
3. Step 3: Examine Selective serotonin reuptake inhibitors (SSRIs). SSRIs specifically block the reuptake of serotonin, which increases its availability in the synaptic cleft, enhancing serotonergic neurotransmission.
4. Step 4: Consider the action of Tricyclic antidepressants (TCAs). TCAs primarily inhibit the reuptake of serotonin and norepinephrine, not primarily enhancing gamma-aminobutyric acid (GABA) transmission, which is more related to anxiolytics or other drug classes.
5. Step 5: Analyze Monoamine oxidase inhibitors (MAOIs). MAOIs inhibit the enzyme monoamine oxidase, which breaks down monoamines like serotonin, norepinephrine, and dopamine, thereby increasing their levels. They do not block dopamine reuptake directly.