Advance directives, or living wills, may not effectively honor end-of-life wishes because life-sustaining treatment preferences often change over time without people being aware of the changes, according to a new study co-authored by UC Irvine researchers Peter Ditto and Elizabeth Loftus.

As a brain-damaged woman named Terri Schiavo lived her final days in 2005, her family's bitter feuding imparted a tragic lesson about the importance of specifying one's wishes for end-of-life medical treatment.