This article describes and analyzes the unique challenges that face psychiatrists and other mental health professionals serving a multicultural population in a limited geographic setting, based on the author's experiences working as a psychiatrist on a mobile crisis unit from 1984 through 1991 on the Lower East Side of Manhattan. Of special importance, the paper presents and provides support for the "interaction hypothesis", which proposes that sociocultural background factors interact with mental disorders to produce dissimilar behavioral expressions of the same disorder among members of different ethnic groups. Concern is voiced that mental health professions, in order to provide effective treatment in multicultural settings, need to understand and accept each ethnic group's idiosyncracies, identity, and background.

Psychiatric disorders on a global scale, combined with rapid national population diversification, demand that mental health professionals worldwide become more informed about the realities of diagnosing and treating a multicultural patient population. Recommendations are offered to enable such professionals to most efficaciously diagnose and treat patients from diverse sociocultural backgrounds.

This article presents a review and assessment of a community Mobile Crisis Intervention Team working on the Lower East Side of Manhattan. Of special importance, a trend is noted involving a changing philosophy and modus operandi. Some reasons are offered to explain the trend and questions are raised about the future of the delivery of mental health services in large urban areas.