She suffers from a disorder and has been without her medication for more than two weeks.
Her parents are asking for help finding her.
The father of 16-year-old Anna Evans posted an emotional video of his daughter on YouTube.
He last saw her on the night of March 3rd inside their Clifton Heights, Delaware County home.
"We watched American Idol together. We kind of hung out, and she seemed pretty happy; nothing amiss," said Tom Evans. "And then she went to bed, and when I woke up, she wasn't home."
Tom and Natalie Evans adopted Anna from Russia when she was 10. Her parents say she is just like any normal teenager who wants to fit in.
They also say she has a fascination with the hip hop culture. They believe she may have gone to Upper Darby or the Philadelphia area to experience "the mean streets" for herself.
They worry because she was recently diagnosed with Reactive Attachment Disorder and is on medication.
"That is what typically adopted children go through. Anna was adopted at the age of 10 from another country. She was recently diagnosed with that, and has been in intensive therapy treatments just recently," said Natalie Evans.
Anna has black hair and grey eyes. She stands 4'10", and weighs about 85 pounds. She may go by the name "Nina".
The Citizens Crime Commission is offering a $2,000 reward. If you know Anna's whereabouts, call the Tipline at 215-546-TIPS.
Her parents posted a "Find Anna Evans" Facebook page. There are already over 1,600 followers. And her parents say they want Anna to know that she is not in trouble.
"Anna, your mom and I miss you so much, and we want you to come home," said Tom Evans.
"Any problems that you are going on, and you think can't get fixed, they can get fixed. Just give us a call. We love you very much," said Natalie Evans.
--------RELATED: "Find Anna Evans" Facebook page
