Which receptor blockade is responsible for causing dry mouth as a side effect during antidepressant treatment?

Explanation

Dry mouth experienced during antidepressant use is primarily due to the inhibition of muscarinic cholinergic receptors. These receptors normally regulate salivary secretion, and their blockade reduces saliva production, leading to dryness. Other receptor types such as serotonergic, dopaminergic, and GABA receptors are not typically implicated in this side effect.