NPS were measured by using the NPI‐Q (31 (link)) which was administered as a structured interview to an informant, usually the spouse. The NPI‐Q is a shorter version of the Neuropsychiatric Inventory (NPI) and is a clinical instrument that is cross‐validated with the standard NPI (31 (link)). We considered the NPI‐Q an appropriate screening instrument because it assesses a broad variety of neuropsychiatric symptoms and was also selected by the Uniform Data Set Initiative of the National Institute on Aging (32 (link)). The NPI‐Q is designed to obtain information on 12 behaviors (i.e., agitation, delusion, hallucination, depression, anxiety, euphoria, apathy, disinhibition, irritability, aberrant motor behavior, sleep, and eating/appetite). A severity scale has scores ranging from 1 to three points (1 = mild; 2 = moderate; and 3 = severe) and a scale for assessing caregiver distress has scores ranging from 0 to five points (0 = no distress; 1 = minimal distress; 2 = mild distress; 3 = moderate distress; 4 = severe distress; and 5 = extreme distress).