In the New England Journal of Medicine, Atheendar S. Venkataramani and Alexander C. Tsai point out that the Deferred Action for Childhood Arrivals (DACA) program has proven to have a quite remarkably positive effect on the health of "dreamers":

“A recent quasi-experimental study compared changes in mental and physical health outcomes among persons who were eligible for DACA with those of a similar group of noncitizens who did not meet at least one of the eligibility criteria. The study showed that rates of moderate or severe psychological distress in the DACA-eligible group fell by nearly 40% relative to rates in the DACA-ineligible group after DACA’s passage. Similarly, descriptive studies of DACA beneficiaries have revealed remarkable improvements in psychological well-being after the program’s implementation. The most recent contribution to this literature has shown, using data on Emergency Medicaid beneficiaries in the state of Oregon, that the mental health benefits of DACA extended across generations: among the children of DACA-eligible mothers — the majority of whom are U.S. citizens by birth — rates of adjustment and anxiety disorders fell by more than half after DACA was implemented.”

Rescinding DACA - as Trump has announced he will do, despite some recent indications that maybe he won't, who knows - "will have profound adverse population-level effects on mental health.