In one aspect, the invention relates to substituted 2-(4-heterocyclylbenzyl)isoindolin-1-one analogs compounds, derivatives thereof, and related compounds, which are useful as positive allosteric modulators of the muscarinic acetylcholine receptor M1 (mAChR M1); synthesis methods for making the compounds; pharmaceutical compositions comprising the compounds; and methods of treating neurological and psychiatric disorders associated with muscarinic acetylcholine receptor dysfunction using the compounds and compositions. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.