Which antipsychotic is listed as weight gain-inducing?

Which antipsychotic is listed as weight gain-inducing?

• A. Olanzapine
• B. Haloperidol
• C. Risperidone
• D. Quetiapine

Answer: (C)

Weight gain with antipsychotics happens because these drugs commonly affect receptors that control appetite and metabolism, especially histamine H1 and serotonin 5-HT2C receptors. When these receptors are blocked, appetite can increase and metabolic processes can shift toward storing more fat, leading to weight gain over time.

Risperidone is known to cause weight gain in a noticeable number of patients, placing it in the weight-gain–associated category among the options. It often produces more weight gain than haloperidol, though typically less than olanzapine or clozapine. Quetiapine can also lead to weight gain, while haloperidol tends to have a smaller effect on weight. Olanzapine, in particular, has a higher risk of weight gain, but within the given choices, risperidone is the one commonly highlighted for this side effect.