A teenager’s daily step count may improve more than their physical health — it may also help protect their mental health.Researchers tracked more than 5,500 adolescents, around age 12, using Fitbits, brain scans and mental health assessments.After one year, teens who took 12,000 or more steps a day had fewer mental health symptoms than those who took fewer than 5,000.More steps were also associated with greater thickness in two regions of the brain involved in motor and cognitive functions.Dr. Claudine Higdon, a child and adolescent psychiatrist at Northwell Health, was not part of the study but calls the findings exciting. “The good thing about it is this particular brain region is really linked with decision making; the attention part of the brain. And so that can thereby improve choices and improve impulse control. And that might also lead to improved mental health.”The researchers say physical activity may release feel-good chemicals like dopamine and serotonin, while lowering cortisol and inflammation, which may help ease anxiety and depression.Dr. Higdon says the takeaway for parents and kids is simple.“Parents: Really encourage your children to walk more throughout the day. Kids: Movement is so key. Just any little bit of walking can make a big difference.”Source: JAMA Network OpenAuthor “Affiliations: Kings College London, University of Massachusetts Amherst .Sign up for our weekly HealthDay newsletter