Uninjured athletes reported concussion-like symptoms in a new study that suggests symptom reporting in the absence of recent concussion is related to male or female sex and preexisting conditions, which can include prior treatment for a psychiatric condition or substance abuse, according to an article published online by JAMA Pediatrics.

Every state in the U.S. has passed legislation pertaining to sport-related concussion. In general, the laws mandate that injured student athletes be evaluated by a qualified health care professional before they can return to participating in sports. Decisions about returning to activity are based on symptom reporting.

Grant L. Iverson, Ph.D., of Harvard Medical School, Boston, and coauthors sought to clarify factors associated with concussion-like symptoms in uninjured adolescents using data from more than 30,000 student athletes. It is important for clinicians to understand factors that may be associated with baseline symptom reporting so they can properly make decisions about when athletes may return to activity.

The authors found symptom reporting was more common in girls than boys and that in the absence of a recent concussion, 19 percent of boys and 28 percent of girls reported a group of symptoms similar to postconcussional syndrome.

Preexisting psychiatric, developmental (e.g., attention-deficit/hyperactivity disorder [ADHD] and learning disability) and neurological factors (e.g., migraines) were associated with higher rates of reporting symptoms that resemble postconcussional syndrome at baseline.

Prior treatment of a prior psychiatric condition was the strongest indicator for symptom reporting in boys, followed by a history of migraines. For girls, the indicators were prior treatment of a psychiatric condition or substance abuse and ADHD.

While prior concussions were modestly associated with increased risk for reporting clusters of symptoms, they were less so than preexisting developmental and psychiatric factors.

"When managing a student athlete with a concussion, it has been widely noted that the athlete should be 'asymptomatic' at rest and with exercise before returning to sports, and sometimes athletes are kept out of school for prolonged periods while they wait for symptoms to resolve, which could have negative consequences for their academic, social and emotional functioning and contribute to symptom reporting. These results reinforce that 'asymptomatic' status after concussion can be difficult to define," the study concludes.