he field of talk therapy is highly subject to fads and pop marketing, in part because good therapists are often charismatic story tellers, and any advice that helps demystify relationships and soothe mental turmoil is like intellectual catnip.

Self-help aisles throb with new titles every year, and daytime talk show hosts regularly chew over psychological issues. Academic researchers can only swallow their objections and hope these waves of pop psychology are doing more good than harm.

Not without charisma herself, Dr. Marsha Linehan, the founder of dialectical behavioral therapy, commands standing-room-only audiences when she gives talks, conducts seminars or presents findings at professional conferences. She has admirers around the world, and acolytes who believe she is a miracle worker who has found the answers.

The therapy she first devised more than 20 years ago has become one of the most talked-about new approaches in decades, and Dr. Linehan has established a company to train therapists and distribute her manuals and materials.

Yet in this case neither therapy nor therapist has lost standing among psychological researchers.

For one thing, Dr. Linehan has completed seven studies of her dialectical approach that are as rigorously controlled as any psychological trials. The National Institute of Mental Health has provided regular support for her work. And her book on the subject is a technical and painstakingly sourced text that reflects a command of psychological research, theory and history. As for the company Dr. Linehan founded, Behavioral Tech of Seattle, she receives no profits from its sales.

The people Dr. Linehan treats have far more serious mental problems than could be responsibly handled with a good self-help book or on a call-in radio show. One patient she saw as a young therapist was a woman with borderline personality disorder who was obsessing about suicide, and seemed to be getting worse in therapy.

The woman was harming herself more often and landing in the hospital, where she felt protected.

"I felt we were really on the edge," Dr. Linehan said. "She was scared, she wanted to die, and there's so little room for error" in these cases.

It was the need to get through to patients like this one - and to do so quickly - that gave rise the central ideas of dialectical therapy, including the combination of understanding for the patients' most bizarre behaviors and relentless insistence that they change them.

Like a parent whose child is throwing a tantrum at the grocery store because he isn't allowed a box of sugary cereal, Dr. Linehan had to find a way of refusing to reward the bad behavior without leaving the child stranded in the aisle.

"You can't walk away, and you can't get the Cocoa Puffs either," she said. "You have to get these people not to go to the hospital when they're feeling suicidal and at the same time have them feel that they're not being left on the floor, that they have some skills to manage."

Dr. Linehan has been careful not to make grand claims for dialectical therapy, beyond that it helps keep some suicidal people alive and out of the hospital. This restraint makes her an unusual figure: an academic researcher and clinician who has managed to promote her brand of therapy without selling out.

"I have seen enthusiasts of this therapy making claims that it's a complete treatment for borderline disorder," said Dr. Drew Westen, a professor of psychiatry, psychology and behavior sciences at Emory University, "but I have never heard Marsha oversell it."

Although dialectical therapy is being used more widely, it may take some work to find a therapist who is trained in the approach. Some practitioners have not undergone formal training, but still incorporate aspects of the therapy into their work. And many clinics have worked with Dr. Linehan's company. The company's Web site, www.behavioraltech.org, includes a list of therapists who are trained in dialectical therapy.