Psychiatric studies of immigrants have yielded contradictory findings regarding rates of mental illness. Current evidence suggests that rates of schizophrenia (and probably other disorders) among immigrant groups are low compared with native-born populations when sending and receiving countries are socially and culturally similar. The rates for immigrants are higher when sending and receiving countries are dissimilar, probably because of multiple social problems faced by immigrants in the receiving country. Refugees who flee their own country because of fears of violence or starvation often have had extremely traumatic experiences, which may result in PTSD and sometimes chronic impairment. Asylum seekers who arrive illegally to seek refuge in a foreign country also may have multiple traumas and experience further distress from their uncertain residency and legal status. Although much is known about the effects of migration, competent culturally sensitive services for migrants remain inadequate to meet the need.