He also published, with Dr. Paul Links, a handbook describing what he called good psychiatric management, intended for nonspecialists, patients and families dealing with the storms of rage and self-loathing of borderline personality. This guide became widely used by doctors.

Dr. Gunderson’s long commitment to people with borderline personality disorder had a hopeful payoff. He collaborated on a long-term study, led by Harvard’s Mary C. Zanarini, which found that most people given a diagnosis of borderline personality eventually recover: some 15 percent in the first year, a third by two years, fully 85 percent after a decade.

“He was the first person to look systematically at the data and figure out what the heck this diagnosis really meant,” said Dr. Glen Gabbard, a clinical professor of psychiatry at Baylor College of Medicine in Houston. “Before John, there were observations, case studies, confusion; after John, we had clarity.”

John Gunder Gunderson was born on June 20, 1942, in Two Rivers, Wis., the youngest of three children. His father, Sherman, was a professor of economics, and his mother, Alma (Walter) Gunderson, was a high school English teacher. He grew up in Oshkosh, graduating from high school there in 1960.

Determined to be a doctor, he entered Johns Hopkins University in Baltimore and found himself in deep water: Everyone else seemed to be pre-med, too, and better prepared than he. He stuck it out, earning his way into a two-year Dartmouth Medical School program that fed Harvard’s medical school, where he finished his degree in 1967.

In 1963, while at Dartmouth, he met Susan Riley, a student at Skidmore, on a blind date. They were married in 1965, and she would go on to work in money management in Boston.

In addition to his wife, he is survived by two children, Craig and Kelly Gunderson, and five grandchildren. His sister and brother died before him.