When it comes to concussion treatment, Dr. Michael Kirkwood, co-director of the Concussion Program at Children’s Hospital Colorado, tells a cautionary tale. One day, a 15-year-old boy suffered a concussion during a high school soccer game. After a day of rest, the young man returned to school; after a week, he seemed fully recovered. Then, 10 days following the injury, he started feeling tired and suffering headaches.

After an urgent care visit followed by rest at home, his symptoms worsened. When another attempt to return to school failed, he stayed home for weeks worrying about permanent brain damage. As a result, he became isolated and depressed. But after the boy visited Children’s Hospital, Kirkwood realized that he was another victim of what’s known as a “nocebo effect.” The boy’s prolonged recovery was due not only to the original brain injury, but also to misconceptions about concussion symptoms and rest.

“Ten years ago, a lot of people were saying go sit in a dark room, don’t interact with your friends, don’t listen to music, don’t go to school,” says Dr. David Howell, director of the Colorado Concussion Research Laboratory at the Anschutz Medical Campus. But that advice was “accepted clinical wisdom” with no actual evidence to support it, adds Kirkwood.

Earlier this year, Kirkwood, along with University of Colorado colleagues Howell and Dr. Julie Wilson, warned physicians about the nocebo effect in patients with concussions in a sports medicine journal.

A nocebo could be described as the evil cousin of a placebo effect—the latter of which refers to the astounding psychological benefit that can come from positive expectations about an illness, injury, or its treatment. (Take, for instance, a study in which the performance of competitive bicyclists was improved with non-caffeinated drinks they thought were caffeinated.) On the other hand, a nocebo effect can promote physiological harmful outcomes by setting negative psychological expectations with treatment.

For example, a doctor who warns you about the side effects of a medication can almost triple the chances that you will suffer those side effects. About half the asthma patients who inhaled a harmless saline solution suffered shortness of breath when they were told the solution contained an allergen.
In regard to head trauma, Howell began clinical research to examine the rest that doctors often prescribe following a concussion. By definition, a concussion is a diffuse brain injury that occurs when a serious blow to the head or body compresses, stretches, twists or otherwise distorts the brain tissue.

(Read more: A New Concussion Test Comes to Denver)

Still, the main issue is that, as exhibited by the aforementioned soccer player, fears and anxiety about lingering effects and long-term consequences make it all too easy to attribute the symptoms to a concussion. As Howell discovered, such heightened anxiety and negative expectations can lead to counterproductive behavior. This nocebo effect only worsens symptoms. Rest is still considered by concussion experts to be important during the first couple of days after an injury. But exercise in the weeks following an injury is increasingly being recognized as a boon for recovery.

This year, Howell published a flurry of six papers on the effects of exercise and concussion. One revealed that teens who exercised more than 160 minutes per week had fewer post-concussive symptoms a month after the concussion versus those who exercised less. Another reported that young athletes who exercised more were able to return to sport activities faster than those who exercised less. Increasingly, Howell was finding that patients who exercised more ended up feeling less depressed, anxious, or dizzy, and had better balance. It countered much of the conventional wisdom about concussion recovery.

“Obviously, there are psychological benefits as well as physical benefits to exercise,” Howell says. “Aerobic exercise at a level below what will make you feel worse will help get blood to your brain.” That increased blood flow provides more oxygen and energy that brains need to heal.

However, the appreciation and understanding for the value and timing of exercise for concussion recovery remains spotty in the medical community. In September, Howell reported that of 211 young athletes who came to the Children’s Hospital Colorado concussion clinic 10 days after a concussion, only 35 had exercised before visiting the clinic. Those who hadn’t were almost six times more likely to experience continuing symptoms 28 days after concussion.

“Twenty-five years ago, nobody was paying attention to concussion. You were told if you have your bell rung, to shake it off on the sideline and get back in the football game. But nowadays, it seems like any hit to the head is being called a concussion,” says Kirkwood. “We want to take concussions very seriously because they are a type of brain injury.” He adds that those who feel they exhibit concussion symptoms should immediately be checked by a trained professional. “At the same time, every time a kid hits their head does not mean they have had a concussion.”

Recently, Howell has been developing a “neuromuscular training program” for patients of the clinic to improve and speed recovery from concussions. Early results indicate that it helps recovery and also reduces other injuries in the weeks and months following a concussion.

“Lots has changed over the years,” Kirkwood wrote in an email, “but one thing that hasn’t is that mistaken beliefs about concussions abound.”

If you believe you have suffered a concussion, the concussion pages of the U.S. Centers for Disease Control and Prevention or Children’s Hospital Colorado can offer valuable information and guidance.