Techniques being used to treat psychological lapses from traumatic brain injuries, the signature wounds suffered by troops in Iraq and Afghanistan, appear to be helpful, but lack rigorous scientific support, a government-appointed panel reported Tuesday after completing the most comprehensive analysis of the evidence to date.
The report, completed by the Institute of Medicine at the request of the Defense Department, concluded that some specific methods — the use of special daily diaries, for instance, to improve memory — were backed by more evidence than others. But it concluded that the evidence base over all was too thin to support any guidelines for which therapies to provide to whom.
Since 2009, the Pentagon has provided more than 71,000 hours of so-called cognitive rehabilitation, and its insurer, Tricare, has covered an additional 54,000 hours in private clinics for active duty, National Guard and retired service members, according to Cynthia O. Smith, a Department of Defense spokeswoman.
Such rehabilitation methods have come under intense scrutiny from family members of veterans who suffered traumatic brain injuries, including those caused by nonpenetrating blasts, as well as wounds from bombs, bullets or blows to the head. Some 20 percent of service members wounded in Iraq and Afghanistan have suffered blows to the face, neck or head, and the number of brain injuries has nearly tripled in the past decade, to more than 30,000 from 11,000.
About 1.7 million American civilians each year suffer traumatic brain injury, many from car accidents.
"I think the panel had a slight bias toward wanting these therapies to work, but at the same time it did not overstate the evidence," said Dr. Jordan Grafman, director of the Traumatic Brain Injury Research Laboratory at the Kessler Foundation Research Center in West Orange, N.J., who was not on the committee.
Dr. Grafman said that applying cognitive rehabilitation techniques, which focus on improving memory, attention and decision making, "is almost a no-lose proposition. It's like going to school; you should get better at what you practice and you shouldn't get worse."
How much better is still an open question.
The expert panel reviewed 90 studies published from 1991 to 2011, involving thousands of patients. Some of their injuries were mild, causing subtle memory deficits; others were severe and disabling. The therapies aimed to improve overall functioning, or to achieve more specific goals, like remembering appointments and chores or organizing and planning tasks.
The panel rated two types of treatment, one focused on memory and the other on social skills, as having a "modest" evidence base. It rated other techniques — for sharpening organizational skills, sustaining focus or improving overall functioning — lower still, with only a hint of evidence to back them up.
Dr. Ira Shoulson, a professor of neurology at Georgetown University Medical Center and chairman of the expert panel, said that evaluating traumatic brain injury treatment was inherently difficult because the severity of injuries varies so widely, techniques are often tailored to individuals, and veterans in particular come in with compound problems, including chronic pain, post-traumatic stress and depression.
The people providing the therapy — nurses, social workers, doctors, psychologists and, ultimately, family members — also vary from case to case. And the approach for each individual often has several components, leaving scientists to ask which made a difference.
"That's a lot of moving targets," Dr. Shoulson said. He and fellow panel members called for larger, better-designed trials that use agreed-upon tools to measure effects — something the field is only just beginning to develop.
Therapies for brain injuries are not well studied "because the whole field is Balkanized," said Dr. Nicholas Schiff, a neuroscientist at Weill Cornell Medical College in New York. "Because there's no infrastructure, no organized plan of attack for what happens after a brain injury, at all stages, you're simply not going to find many" large, well-designed studies, he said.
As a rule, therapists do not begin intensive cognitive rehabilitation until months after an injury, to give brain tissue a chance to heal. But the underlying molecular processes are not well understood, Dr. Grafman said.