Provided are methods of treating psychological diseases and conditions by administration of a preferential muscarinic acetylcholine receptor M1 antagonist, optionally with at least one antidepressant other than a selective muscarinic acetylcholine receptor M1 antagonist. The invention also provides for pharmaceutical compositions and kits for administration of at least one selective muscarinic acetylcholine receptor M1 antagonist in combination with at least one antidepressant other than a selective muscarinic acetylcholine receptor M1 antagonist.