David Chen's parents sent him to Fujian to be raised by his grandparents before he was 1 year old. When he was 5, they brought him back to New York to start school.

Chen, now 26 and a student at Touro College of Osteopathic Medicine in New York, said: "I didn't know who they were - they were strangers to me. I was pretty distant with them."

To pay for him to go to China, his parents worked 14 hours a day at different restaurants, often seven days a week. The time the family spent together was limited.

By the time Chen started in the third grade, he was starting to have suicidal thoughts because of being separated from his grandparents, the difficulty of learning English, and bullying at school.

But instead of sharing his thoughts with his parents, he chose to keep his feelings to himself. "I definitely had my emotions bottled up," he said.

A mother working in Boston's Chinatown, who requested anonymity, sent her son to her hometown in China after he was born in the US. "Even though I missed him all the time, there's just no way you can get everything you want. You want to make money, but you also want to take care of your kid ... so we had to give something up," she said.