Passage Summary: A writer suggests that Alzheimer's damage happens because the brain's immune system overreacts to protein buildup and ends up poisoning healthy cells.

Conclusion: The mental decline seen in Alzheimer's patients is caused by the brain's own immune cells, known as microglia.

Reasoning: Anti-inflammatory drugs help slow the disease, and microglia release toxins to attack protein deposits, which inadvertently kills healthy brain tissue.

Analysis: To strengthen this argument, we need to solidify the causal link between the microglia's 'poison' and the actual cognitive symptoms. The argument currently shows a correlation—microglia attack deposits and healthy cells die—but it would be even stronger if we knew that the specific toxins released are indeed capable of causing the observed mental deterioration. Look for an answer that confirms the 'friendly fire' from the immune system is the primary driver of the disease's symptoms rather than just a side effect of the protein itself.