With the recent rapid evolution of molecular technologies, "genetic markers" have been identified for a multiplicity of human characteristics, temperamental traits, and frank psychiatric dysfunctions. This development demands the setting forth of basic concepts and principles to help academicians and clinicians understand the emerging science of genetic origins of psychopathological states.

Genetics of Mental Disorders, a primer on psychiatric genetics whose authors have long experience in genetic research and teaching, is a strong candidate for becoming a basic text for those embarking on careers in research, teaching, or clinical practice. With its admirable blend of fundamental facts and clinical applications, the book will be helpful to professionals in various disciplines.

Particularly useful are the highlighted summary statements labeled "key points" and the nuggets called "clinical tips." These help the reader fixate the more detailed and complex material from preceding sections.

The reading list is current, and most of the references are from the past decade. The authors also usefully identify resources available on the Internet. A comprehensive glossary of applicable terms is a convenient feature for readers seeking to become more articulate in their understanding of genetics. Particularly useful clinically are sections in chapter 3 on comorbidity of psychiatric disorders; the authors clarify what is meant by spectrum conditions as well as their genetic implications.

Rather than offer a reductionist approach that presents human thought, emotions, and behaviors merely as products of neurochemical processes, this book emphasizes the complexity of genetic determinants of clinical disorders interacting with environmental factors, accrued experiences, ongoing familial interactions, psychological processes, and other nonbiologic phenomena.

A familiarity with the basic scientific formulations of genetic research, coupled with the tentative and incomplete knowledge of how identified genes, involved proteins, affected enzyme systems, and environmental factors interact to produce psychopathology or good mental health, will lead us to be both confident and modest in providing genetic counseling about conditions that are clearly familial and inherited. The demand will grow for information about the likelihood of genetic transmission of various clinical disorders.

How to approach families who wish to be informed as they make reproductive choices is well developed in the chapter on clinical applications. Using the metaphor of a tapestry to explain psychopathology, the authors remark, "Flaws in this tapestry can be repaired with the threads of biology, psychological development, insight, spiritual expression, and critical life events."

In a discussion about the future of psychiatric genetics, the need for careful shaping of ethical and legal principles is well developed.

With the inquiring and deliberate approach supported by the authors, we can look forward not only to exciting advances in our understanding of genetic etiologies of mental disorders but also to the application of those findings to diagnosis, prevention, early detection, and more definitive treatment modalities.

Dr. Hostetter is clinical professor at the University of Miami School of Medicine in Miami, Florida, and senior partner of a private practice in Hershey, Pennsylvania.