Dr. Robert Butler, who passed away July 4, 2010, is credited with the idea that reminiscing could be therapeutic. Butler, a psychiatrist with a specialty in geriatric medicine, first spoke of the idea of a "life review" in the 1960s. At the time, psychiatrists did not think it was a good idea for people to always be "living in the past", but Butler disagreed and made it clear that reminiscence was a natural process of healthy aging.

Reminiscence therapy covers a number of topics. Sometimes it is done in a group but people can do it one-on-one as well. There is a great deal of flexibility in the approach, but people typically describe...
The people who shaped their lives & their family members
Childhood memories and how history changed their lives
Transitions at different points of life
Love, marriage, children, grandchildren
The joys and challenges through the years

The #1 reason people reminisce is to teach and inform, but through reminiscence people can be reminded of their accomplishments, set some goals for the future, and come to terms with the past. Reminiscence therapy has also been found to lower depression and increase feelings of happiness, especially in older populations.

The relationships that form through reminiscence therapy can be another excellent outcome.
Tools for reminiscence therapy...
Life Story Journal
Memory Journal