Caring for someone with Alzheimer's disease can take a huge emotional toll on the caregiver.

But caregivers who receive preventive counseling and support can significantly reduce their risk of developing depression, according to research published in the American Journal of Psychiatry .

The researchers also discovered that the effect was long-lasting. In fact, the risk of depression was still reduced as long as three years after the initial counseling sessions took place. Also, the risk of depression was reduced by the counseling sessions even if the caregiver's loved one had died or been placed in a nursing home.

For the study, researchers from the New York University School of Medicine recruited more than 400 spouses of people with Alzheimer's disease. All of the spouses were acting as caregivers at the start of the study.

Half of the group received the support normally given Alzheimer's families, which includes information about available resources, available crisis counseling and information about support groups. This group received no formal counseling.

The other half of the group -- the enhanced group -- received the normal support plus two individual and four family counseling sessions. After those sessions, volunteers in this group were also offered the chance to talk with a counselor whenever they felt they needed additional help.

When the study began, each group had similar levels of depressive symptoms. After a year, about 30 percent of the caregivers in the enhanced group had clinical depression symptoms, compared with 45 percent of those in the normal support group.

Three years later, the differences persisted. After five years, however, the benefits from the initial counseling sessions had faded and both groups reported similar levels of depression.

For people trying to cope with the daily tasks of caring for someone with Alzheimer's or another form of dementia, the Family Caregiver Alliance offers this advice: