I think your dad got argumentative not because he succumbed into Alzheimer's but because that was his personality i.e. the way he used to interact with people. While he could control his behaviour most of his life, in the final stages he lost that control, as much as he lost his immediate memory of his surroundings. Alzheimer's aggravates any personality/behavioural idiosyncrasies we have. If you tend to be "argumentative" or "explosive" now, you will be more so if you succumb to Alzheimer's. And you can do nothing about it so you should not worry about it. You can't help it because no matter what you current (or future if you work hard on it) personality is, Alzheimer's will always ruin the life of yours next to kin. They will feel like their lifelong work to be with you and support you, becoming lost, like you are destroying all emotional life. Maybe better to just decrease the chance of getting Alzheimer's in the first place by eating healthy, being physically & mentally active, etc. Your risk is higher due to hereditary nature of that nasty disease, but you're not necessarily doomed to get it, just higher risk. In the end higher risk does not mean certainty and you can influence it. BTW my dad died from Alzheimer's but I'm not worrying about it. But I'm trying to decrease the risk for myself by not doing the wrong things my dad did: sedentary lifestyle, fatty food, overweight, no social connections.