INS and major depressive disorder: Diabetes mellitus is closely intertwined with diminished neurocognitive function, driven by various mechanisms, including vascular diseases and defects in insulin metabolism, which can lead to the deposition of amyloid-β in the central nervous system.[70] The use of insulin therapy, while crucial in diabetes management, can have unintended consequences such as decreased IDE production, fostering the formation of amyloid plaques and glycated end products associated with dementia, particularly AD.[71] Notably, diabetes often coexists with depression, a comorbidity associated with dementia.