A deficiency in which neurotransmitter is linked to Alzheimer's disease?

Alzheimer's disease is primarily associated with a deficiency in acetylcholine, a neurotransmitter that plays a crucial role in memory and cognitive functions. Research has shown that individuals with Alzheimer's often have significantly lower levels of acetylcholine in their brains. This deficiency is linked to the condition's characteristic cognitive decline and memory loss, as acetylcholine is vital for learning and memory processes. Medications used to treat Alzheimer's often aim to increase the levels of acetylcholine or enhance its action, highlighting its importance in managing the disease.

In contrast, while dopamine, norepinephrine, and serotonin play important roles in other neurological and psychiatric conditions, their dysregulation is not primarily associated with Alzheimer's. For instance, dopamine is often linked to movement disorders such as Parkinson's disease, norepinephrine is related to stress and arousal responses, and serotonin is generally tied to mood regulation. Thus, acetylcholine's specific connection to memory impairment in Alzheimer's makes it the correct choice.