>> reporter: for lauren huddle and her family, a day like today used to feel impossible. >> i have pretty anxiety and depression, too. i just wanted to stay inside and not do much, and it wasn't working. it was getting worse and worse. >> reporter: lauren's 9-year-old son was dealing with similar issues, so the huddles' family physician wrote them a prescription, not for pills or drugs, but for a big dose of mother nature. five times a week, spend 30 minutes at this park near their home. >> now, i consider it more important than any medication i can prescribe. >> reporter: it's a growing field of medicine called ecotherapy. pediatrician dr. robert czar started park rx america, a national initiative which now includes more than 50 doctors in 11 states. why not just go to a gym? what's the evidence behind going outside? >> scientists have actually looked at this, and what we've found out is that moving out doors is actually better, more health than moving indoors. >> reporter: studies show ecotherapy can help patients with depression, attention deficit disorder, and chronic diseases like di

. >> reporter: lauren huddle got her prescription three weeks ago. >> going out there little bit by little bit my temperament was better and my anxiety started to decrease. >> reporter: when good shelt as cinch. >> you're sting going. >> reporter: as a walk in the park. dr. john torres, nbc news, washington. >> sound of water. >>> when we come back, the long journey home for the man who never should have been sent to prison in the first place. >>> the richest person in the world became even richer this holiday weekend. jeff besos saw his net worth top $100 billion after amazon stock jumped more than 2% on black friday. that translated into a more than $2 billion bump in his net worth. not too bad for one day's work. >>> the fortunes of another man changed dramatically this week as well. after four decades in prison, he was pardoned by california's governor after dna tests showed he was wrongfully convicted. steve patterson has more. >> my first thanksgiving in 38 years. >> reporter: for craig coley, it's the little things. like leftovers after thanksgiving. free for the first time in after

stay outside get exercise and we'll all be warm if we huddle together right lauren. >> jenny joyce, iook bundled up. that's good. stay warm out there. all right. 7:33 at this hour. >>> now to developing story out of radnor. creepy case ends with an arrest of a guy who police say is a socio our area to track down a local teenager who is a social media star. and then contacted the teenager teenager's parents. dave kinchp from there. >> reporter: it's the face 18-year-old male instagram star in delaware county. >> this was a significantly serious incident. >> reporter: radnor police say 30-year-old michael leib drove all the way from michigan to quote hook up with an 18-year-old entertainer well known on youtube. after leib was spotted at their house tuesday cops pretended to be the boy using his cell phone to lure the suspect until he was in cuffs. >> because the parents had their child and the parents the police school district prior to arresting him making sure that the family was safe, the school was safe. >> reporter: copsib started messaging the teen on instagram weeks ago using a