Before Sept. 11, Muslim Americans were largely ignored in the psychological literature, says Mona M. Amer, PhD, an associate professor of psychology at the American University in Cairo. While there was a more than 900 percent increase in the number of publications in the decade following that terrorist attack, many of those publications have been based on anecdotal evidence rather than empirical data. Because of that, she says, many of the claims made in the psychological literature can't yet be confirmed.

For example, says Amer, many publications talk about how Muslims turn to religion and religious leaders for support when faced with stress and emotional distress. But, she says, polling research shows that most Muslim Americans don't identify with the mosque community.

Researchers face huge challenges, says Amer. In addition to a lack of funding, potential language barriers and difficulties identifying study samples, many Muslim Americans may not want to discuss mental health issues, especially when Muslims are already portrayed so negatively, says Amer. "Many may be suspicious about why they're being asked questions," she says.

Another challenge is the frequent conflation of Muslim Americans and Arab Americans by both researchers and those intent on discriminating against Muslims, says Germine H. Awad, PhD, an associate professor of educational psychology at the University of Texas at Austin.

"Any time anyone talks about Muslims, the picture conjured is of an Arab," says Awad. But, she says, most Muslim Americans aren't even ethnically Arabs. (The largest Muslim American groups are African Americans and South Asians from India and Pakistan, Amer points out.) "And even though most Arabs in the U.S. are actually of the Christian religion," says Awad, "they also experience a lot of discrimination because of the assumption that they're Muslim." Sikhs are also frequently mistaken for Muslims and thus targeted for discrimination.

Meanwhile, the need for more research is urgent. "There's no doubt that the Trump presidency is going to be associated with greater stressors for the Muslim community, which may in turn contribute to distress and mental health symptoms," Amer says.

—Rebecca A. Clay