As clients’ bodies slow down during the course of retirement, health care costs rise and discretionary spending declines — but what should an advisor do as a client’s ability to think and reason decreases?

Brie Williams, head of practice management at Boston-based State Street Global Advisors, says advisors should plan ahead for a client’s cognitive decline.

“Look at it as a form of risk management,” Williams says. “We purchase insurance to manage the risk of death or disability or in case we need long-term care. Here, you’re planning for one of life’s most unpredictable events.”

Williams watched first hand as her father’s mental status deteriorated during a battle with brain cancer.

Over 18 months, the aggressive cancer took him from an ‘invincible’ figure in Williams’ life to a state of dementia so severe that he was unable to make his own decisions, Williams says, but the onset was so gradual no one recognized it until a seizure drove him off the road at age 65.

“The cause was stage IV glioblastoma, a malignant brain tumor, and it was his kryptonite,” Williams says. “My parents had created a nancial plan long before the diagnosis, but it did not account for the possibility of cognitive decline. The belief was that time was on our side — they were both healthy and embraced turning 60 as the new 50. So there was a bit of a scramble to put the necessary puzzle pieces in place when life threw us a curveball.”

According to The Impact of Aging on Financial Decisions, a report from State Street, the ability to make sound financial decisions is often among the first abilities lost during a person’s cognitive decline.

Williams cites data from the Brookings Institute, which claims that an individual’s ability to make financial decisions peaks in their 50s, and declines sharply through their late 60s and 70s.

“To a certain extent, this is where a financial advisor can step in and help shoulder some of the burden,” Williams says. “However, once something like Alzheimer’s or advanced dementia sets in, it becomes very difficult to put together a plan to address cognitive decline.”

State Street’s research found that 72 percent of advisors say they are providing their clients with substantial information about the impact of aging on financial decisions, however, less than one in five investors, 17 percent, say they have discussed the topic with their advisor, and of those who have, only around a quarter, or 27 percent, are satisfied with the information and support their advisors are giving them around the topic.