Remind bosses: Don't make presumptions (or comments) about alcohol treatment.

While you can fire any employee who is drunk on the job, a person's alcoholism may be an FMLA-covered "serious health condition" that would require job-protected leave.

If an employee returns to work after taking FMLA leave to rehab from a drinking problem, warn supervisors to check their presumptions about alcoholism--and hold their tongues. Saying or doing the wrong thing could violate the FMLA, the ADA or both.

Recent case: Leslie, a nurse who conducted home healthcare visits, always earned good reviews. Over a 12-month span, she took two short FMLA leaves to seek treatment for alcoholism and depression. Before returning to work, she provided a medical certification showing she could perform the core functions of her job.

But once she returned to work, her supervisor began micromanaging her, creating additional paperwork and making hostile comments about needing to...