Lawrence Kolb, who died October 20 at 95, was a former president of the American Psychiatric Association who was among the pioneers of understanding post-traumatic stress disorder, which he first encountered as “battle fatigue” when he served as a Navy doctor during World War II.

For more than two decades, Kolb was director of the New York State Psychiatric Institute and chairman of the department of psychiatry at the Columbia University College of Physicians and Surgeons. He left both posts in 1975 to become the New York State commissioner of mental hygiene, later making plans for the closure of several aging state mental facilities.

Kolb also wrote “Modern Clinical Psychiatry,” which for many years was a standard text in the field.

Kolb was the son of another well-known psychiatrist, also named Lawrence Kolb. Kolb Sr. was a pioneering expert on narcotics whose book “Drug Addiction: A Medical Problem” held that alcohol was more dangerous than opiates. The book set the agenda for proponents of drug legalization.

The Kolb family first lived in New York, where Kolb Sr. diagnosed mental illness in immigrants at Ellis Island. Then a series of postings led the Kolbs around the nation, including several years at the National Hygienic Laboratory in Washington, D.C.

Between 1928 and 1931, the family lived in Dublin, Ireland, which allowed Kolb Jr. to attend Trinity College. He attended medical school at Johns Hopkins, where he specialized in neurology, and he was subsequently certified in psychiatry by the Mayo Clinic. Among his research specialties was phantom limb syndrome; his paper “The Painful Phantom” (1937) was widely discussed.

During World War II, Kolb served as a Navy doctor. He was stationed aboard hospital ships and was put in charge of a battle fatigue clinic in Portsmouth, Va. The sailors he treated for traumatic memories would become the models for work he did on PTSD decades later.

After the war, Kolb joined the newly established National Institute of Mental Health, where he helped organize the research branch.

In 1954, Kolb came to the NYSPI, where he committed the institute to serving community mental health needs by opening the Washington Heights Community Service. He also planned and developed a research annex on the Columbia campus that is named in his honor.

After retiring as state mental hygiene commissioner in 1978, Kolb stayed in Albany and took a position as a distinguished physician with the U.S. Department of Veterans Affairs. He turned his attention to PTSD, then a controversial and little-understood phenomenon that had been in and out of the Diagnostic and Statistical Manual of Mental Disorders over its various revisions.

It was actually a return to a longstanding interest that he had first studied at Johns Hopkins in the 1930s. He suspected that PTSD had something in common with startle reactions, which he had investigated by purchasing a few Tennessee startle goats, famous for fainting when shouted at.

Kolb proposed a physiological basis for the disorder, which he observed in hospitalized Vietnam veterans. In his model, the sensory overload of intense trauma actually caused neuronal changes. In a memoir he wrote in 2005, Kolb was hopeful that early intervention could prevent PTSD from becoming chronic.

“It was Kolb’s laboratory … that provided most of the data to justify the diagnosis of PTSD,” Charles Figley wrote in “Mapping Trauma and Its Wake” (2005).

Kolb’s wife of 51 years died in 1987 and he eventually retired to Sea Island, Ga., where he lived for several years with a girlfriend. Surviving are two daughters and six grandchildren.