Family members caring for people with Alzheimer's disease are often reluctant to talk about common but treatable behavioural changes such as mood swings and aggression, a new survey suggests.

The survey was conducted for the charity Alzheimer's Foundation for Caregiving in Canada. The majority of respondents said they had observed agitation. More than a third witnessed aggression, and 23 per cent of caregivers said they felt scared or threatened by the behaviour.

Caregivers in Quebec were the least likely in Canada to be open about the fact that someone close to them had Alzheimer's disease.

Christopher Wynn of Montreal shot a documentary during the years he helped care for his father at home. Wynn recalled that his father had dramatic mood swings during which he would go from being happy to upset. The anger was directed mainly at himself but also at his wife and son.

Wynn’s father started showing signs of aggression after he moved to a long-term care facility.

Nursing staff told the family that he bit a female staff member one day, but Wynn said that simply changing the subject, talking about something pleasant or turning on the radio to play some music helped to improve his father's mood.

Aside from drugs, there are strategies to deal with the changes in behaviour that can accompany Alzheimer's, said Dr. Fasi Massoud, a geriatrician at Centre hospitalier de l’Université de Montréal.

"Certain behaviours are triggered by certain circumstances in their everyday living, and we try to avoid these circumstances," Massoud said.

Knowing what to expect can help caregivers, said Taras Rohatyn, president of the caregiving foundation, based in Richmond Hill, Ont.

"Reaching out for help, taking advantage of support services and exploring possible interventions can make a world of difference," said Rohatyn.

Harris/Decima conducted the online survey of 509 caregivers between Oct. 27 and Nov. 11, 2008. The respondents included 250 primary caregivers for someone with Alzheimer's disease and 259 family members or close friends involved in the ongoing care of someone with Alzheimer's disease.

The data were weighted by gender, age and region to reflect the Canadian population.