Which of the following statements about antidepressants are true?
I. All first and second-generation antidepressants target serotonin reuptake.
II. Second-generation antidepressants generally have fewer side effects.
III. Monoamine oxidase inhibitors (MAOI) increase the amount of serotonin in the synaptic gap.

• A. I & II.
• B. I & III.
• C. II & III.
• D. I, II, & III.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the key terms in the problem. 'First and second-generation antidepressants' refer to different classes of drugs used to treat depression. First-generation includes tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs), while second-generation includes selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs).
2. Step 2: Analyze statement I. First-generation antidepressants (e.g., MAOIs) do not primarily target serotonin reuptake; instead, they inhibit the enzyme monoamine oxidase, which breaks down serotonin, norepinephrine, and dopamine. Second-generation antidepressants, such as SSRIs, do target serotonin reuptake. Therefore, statement I is partially incorrect.
3. Step 3: Evaluate statement II. Second-generation antidepressants, like SSRIs, are designed to have fewer side effects compared to first-generation antidepressants, such as MAOIs and TCAs, which often have more severe side effects. This makes statement II true.
4. Step 4: Assess statement III. Monoamine oxidase inhibitors (MAOIs) work by inhibiting the enzyme monoamine oxidase, which increases the levels of neurotransmitters like serotonin in the synaptic gap. This makes statement III true.
5. Step 5: Combine the analysis. Based on the evaluation, statement I is incorrect, while statements II and III are correct. Therefore, the correct answer is 'II & III.'