The parent training seems to work because it lets children confront their anxieties, says Anne Marie Albano, a psychologist at Columbia University.

Prescription medication may be enormously helpful, but "just taking a pill is usually not enough," says Dr. Diana Samuel, an assistant professor of clinical psychiatry.

Dr. Kelly Posner Gerstenhaber, a psychiatry professor at Columbia University, helped lead a suicide prevention event in Parkland last year.

The study led by Dr. Mack and Dr. Martin Leon, an interventional cardiologist at Columbia University in New York, tracked deaths, disabling strokes, and hospitalizations.