Which antidepressant is least likely to cause weight gain in a patient with a BMI of 32 kg/m²?

Bupropion is the least likely antidepressant to cause weight gain among the options provided. This is largely due to its unique mechanism of action, which primarily inhibits the reuptake of dopamine and norepinephrine, rather than serotonin, which is a common target for many antidepressants.

Research indicates that bupropion is often associated with weight neutral effects or even weight loss, particularly in patients who are prone to weight gain from other antidepressant medications. This makes it a favorable choice for individuals with a higher BMI, like a patient with a BMI of 32 kg/m², as they might be particularly concerned about the potential for further weight gain.

In contrast, other options listed—such as sertraline, citalopram, and amitriptyline—are more commonly associated with weight gain. Sertraline and citalopram are selective serotonin reuptake inhibitors (SSRIs), which can lead to increased appetite and weight gain in some patients. Amitriptyline, a tricyclic antidepressant, is well-known for its sedative effects and propensity to cause weight gain due to its antihistaminic properties and potential to increase appetite. Thus, bupropion stands out among these options as the