Bereavement refers to the expected reactions and sadness associated with the loss of a loved one. It has been reported that the loss of a spouse is rated as the major life stressor among survivors of varying ages and diverse cultural backgrounds. Statistics have shown that in the United States over 800,000 men and women lose a spouse each year.

A wide range of symptoms has been associated with bereavement including; depressed mood, tearfulness, sleep disturbances, and irrational behavior. Previous studies have shown that up to 50% of bereaved individuals can develop major depression. Bereavement has also been associated with dysfunction of the immune system. As a result, bereaved adults are more vulnerable to infection. However, the exact relationship between bereavement and immunity is uncertain.

Researchers firmly believe that a relationship does exist between stress, more specifically bereavement, immunity, and the increased chance of dying following the loss of a long-term spouse.

The objective of this study is to find possible links between bereavement, depression, and the immune system. This study will follow a group of elderly bereaved spouses and a group of elderly people who have not lost a long-term spouse. The group of bereaved individuals will be followed for approximately 13 months after the loss of their spouse and the group of controls will be followed for 13 months after entering the study. Researchers will make note of any clinical, biological, and immunological changes in any participants of the study.