When Caplin & Drysdale founder Mortimer Caplin turned 100 last summer, he recalled his early years as a lawyer, and how his colleagues enjoyed liquor in the office each evening. He liked the tradition, so he kept bourbon and soda behind a globe on a shelf in his own Washington, D.C., office. “I wanted it to be a special place,” he said.

Caplin's office happy hours ended years ago, like end-of-day cocktails in most professional offices. But a culture of work-related drinking persists in many places in Big Law—and that can cause problems in a profession that is especially prone to alcoholism.

The legal industry is well aware of the alarming statistics: One-third of attorneys drink too much, with a significant percentage acknowledging they have a problem.