Based on surveys and professional experience, she estimates that as many as half of all alcoholics are high-functioning types. The abuse can go on for decades until and unless some alcohol-related crisis occurs, like being arrested for drunken driving, exposed for having made unwanted sexual advances or being asked for a divorce when their spouses can no longer tolerate the abusive drinking.

Or, like Ms. Benton, they may seek help after recognizing that no matter what they try, they are unable to drink normally and fear that sooner or later their luck will run out.

Many well-known people have publicly acknowledged their battles with alcohol and entered recovery before their lives were destroyed. Among those listed by Ms. Benton are Betty Ford, the astronaut Buzz Aldrin, the actresses Elizabeth Taylor and Mary Tyler Moore, the actor Robin Williams, the singers Keith Urban and Eric Clapton, the football legend Joe Namath and former President George W. Bush.

But there are millions of others  including dentists and doctors, professors and teachers, lawyers and judges, journalists and authors, firemen and C.E.O.’s of major companies  who work for years while abusing alcohol, sometimes putting their lives, and the lives of others, at great risk. Surgeons have been known to operate with shaking hands, yet colleagues who knew or suspected that alcohol abuse was the cause failed to confront the doctor. Employees who suspect a problem often cover up for their bosses.

Ms. Benton emphasized that people in positions of power are often the hardest to detect and help because they tend not to be closely supervised at work, they are assumed to be able to deal successfully with the pressures of their jobs, their high pay enables them to escape the financial consequences of excessive drinking, and they see drinking as their reward for hard work.