## **Core Concept**
The question tests knowledge of the side-effect profiles of various antidepressants, specifically focusing on their propensity to cause sexual side-effects. Antidepressants can be broadly classified based on their mechanism of action, which influences their side-effect profiles. Sexual side-effects include decreased libido, erectile dysfunction, and anorgasmia.

## **Why the Correct Answer is Right**
Mirtazapine (**) is an antidepressant that acts as a noradrenergic and specific serotonergic antidepressant (NaSSA). It has a unique mechanism of action that involves antagonism of central presynaptic α2-adrenergic inhibitory autoreceptors and heteroreceptors, leading to an increase in central noradrenergic and serotonergic activity. Mirtazapine has a lower incidence of sexual side-effects compared to other antidepressants like SSRIs (Selective Serotonin Reuptake Inhibitors) and some SNRIs (Serotonin and Norepinephrine Reuptake Inhibitors), which frequently cause sexual dysfunction due to their serotonergic effects.

## **Why Each Wrong Option is Incorrect**
- **Option A:** SSRIs are well-known to cause sexual side-effects, including decreased libido, erectile dysfunction, and anorgasmia, due to their effect on serotonin levels.
- **Option B:** SNRIs, similar to SSRIs, can also lead to sexual side-effects, although the incidence may vary among different drugs within this class.
- **Option D:** While not specified, if this option includes other types of antidepressants like tricyclic antidepressants (TCAs) or MAOIs (Monoamine Oxidase Inhibitors), these can have various side-effects, but sexual side-effects are still common, especially with the SSRIs and SNRIs.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that when sexual side-effects are a concern, mirtazapine, along with bupropion (a norepinephrine-dopamine reuptake inhibitor), are often considered as alternatives to SSRIs or SNRIs due to their lower risk of causing sexual dysfunction.

## **Correct Answer:** . Mirtazapine