A new study that will be published in the November issue of "Pediatrics," the journal of the American Academy of Pediatrics finds that gender and family dynamics play a part in how long concussion symptoms last.

The study found that being female, having a mood disorder before the injury, having a lower family income or family discord might play a part in concussion recovery.

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Of the 347 children with a mild traumatic brain injury, a complicated mild traumatic brain injury or an orthopedic injury who were enrolled in this study, 25 percent to 31 percent, depending on which type of injury, still had symptoms a year after the injury. These symptoms included difficulty concentrating, headache or irritability.

Girls had a "significant increase" in symptoms did not resolve within 12 months. They were twice as likely to have concussion symptoms a year later.

RELATED: Girls in sports have more concussions than boys

What does this mean: Children should be followed by their pediatrician after the injury to screen for difficulties at least a year after the injury.