"I was crying so bad. I wanted to go back home my first year," says Mamic, now 27 and a third-year medical student at Loyola University's Stritch School of Medicine in suburban Chicago. "You have to start from scratch."
But Mamic had a strong support system — a tightknit family and a large and active community of Croatian immigrants. He also had sports, a shared love for basketball that helped bridge the gap.
And, he says, he and his sister were very social and made friends easily, a factor that Greenberg says is key.
"Kids who are flexible, kids who are engaging, kids who have a likeability factor ... and who can engage both adults and kids — these are the ones who are most resilient," she says.
Tabakh, the Russian immigrant in New York, says she also watched her mother work her way through dental school here because her Soviet dental degree wasn't fully recognized in the United States. Tabakh's parents then set up a dental practice that still exists today.
That gave her motivation to succeed, she says.
But for teens who arrive today, there can be a whole new set of pressures.
In Minneapolis — where a number of disaffected young Somali men have been recruited to fight with a terrorist group in their former homeland — community members such as Abdirizak Bihi are attempting to build a support network. Bihi, whose nephew died in Africa after being recruited, says he and others are trying to teach parents to recognize when a child is being recruited, and involve kids from a young age in positive activities like sports.
He said an early, erroneous report about a black immigrant being connected to the marathon bombings had the community worried, "and when they found out it was not a Somali, there was a tremendous sense of relief."
Young immigrants who lack legal status face additional stresses. One support effort for them was a handbook for schools written by a 21-year-old Polish immigrant in Chicago, Sylvia Rusin. Among other things, the book suggests creating "safe zones" so students can openly talk about their immigration status and get support. Many of those students deal with depression and anxiety.
The Boston bombings have only added to the anxiety — by creating more anti-immigrant sentiment and potentially increasing opposition to proposals to allow more immigrants legal residence.
"It's very difficult to develop a sense of belonging, especially if you're part of a community that is not positively recognized," says Leisy Abrego, an assistant professor of Chicano studies at UCLA.
That often includes Muslim and Arab immigrants, says Saeed Khan, a lecturer at Wayne State University in Michigan, whose expertise includes ethnic identity and Muslim culture.
"They come into a culture that has really been defined by 9/11," Khan says, as the Tsarnaev brothers, both Muslim, would have done.
Hassan Bawab, a native of Lebanon, was a college student in Texas when the Sept. 11, 2001, attacks happened.
"All of that put extra pressure on me. They think that you are THAT person," says Bawab, who came to this country at age 18 and sometimes has faced taunts and aggression.
Some friends changed their names to blend in, he says, but he chose not to.
"I'm proud of where I came from and I'm proud of who I am," says Bawab, who eventually started a web development business called Magic Logix in suburban Dallas.
Now 32, he also became a U.S. citizen recently — and says he'd rather focus on helping people in his adopted homeland better understand who he is.
"You have to accept the fact that you're coming into their country," Bawab says. "You have to be patient."
That can be difficult for a young person.
But when it comes to the Boston bombings, Khan also thinks it's a mistake to focus only on the suspects' immigrant status.
"We're missing a point of a broader social malaise," Khan says, noting that the suspects in the Colorado movie theater and Connecticut school shootings were not immigrants.
"We're living in a time where alienation of youth is becoming an epidemic."
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