WASHINGTON – For people with Alzheimer's disease, a hospital stay may prove catastrophic.

People with dementia are far more likely to be hospitalized than other older adults, often for preventable reasons like an infection that wasn't noticed early enough. Hospitals can be upsetting to anyone, but consider the added fear factor if you can't remember where you are or why strangers keep poking you.

Now a new study highlights the lingering ill effects: Being hospitalized seems to increase the chances of Alzheimer's patients moving into a nursing home – or even dying – within the next year, Harvard researchers reported Monday. The risk is higher if those patients experience what's called delirium, a state of extra confusion and agitation, during their stay.