Wallace acknowledges he once attempted suicide

In an upcoming "60 Minutes" special, Mike Wallace acknowledges that he tried to commit suicide two decades ago.

The 88-year-old Wallace, who is retiring from full-time correspondent duties, is the subject of a retrospective, "I'm Mike Wallace," that will air Sunday on CBS.

Wallace has openly talked about problems with depression but never said publicly that it got to the point of a suicide attempt. But when "60 Minutes" colleague Morley Safer questions him about it, Wallace says he did once attempt it.

Wallace vaguely relates the circumstances behind the attempt, which involved taking an excess of pills, but says that the 20 years since "have been the best in my life.