Ellis friend and spokeswoman Gayle Rosellini said he died of kidney and heart failure in his Manhattan home -- above the institute he founded -- after a long illness, The New York Times reported Wednesday.

Ellis developed a technique called rational emotive behavior therapy, or R.E.B.T., in the 1950s. The approach was a stark contrast to the slow-moving methodology developed by Sigmund Freud, the expert followed by most psychotherapists at the time.

R.E.B.T called for short-term therapy that encouraged patients to focus on the present and take immediate action to change unhealthy behaviors.

"Neurosis," Ellis once said, was "just a high-class word for whining."

He founded his Manhattan institute in 1959.

"I was hated by practically all psychologists and psychiatrists," he told the Times in 2004.

He said they thought his approach was "superficial and stupid," and "they resented that I said therapy doesn't have to take years."

Ellis is survived by his wife, Debbie Joffe-Ellis, a psychologist and former assistant.