If ever a book could be called timely, this is it. Sleep disorders medicine has made rapid advances in recent years. The field has attained growing respectability, with a textbook recently published, a congressionally man dated National Commission on Sleep Disorders Research, and a growing public awareness of the importance of sleep disorders. However, this rapid growth has made the discrepancy among certain components of the field all the more obvious. Thus, we find that patients who complain of insom nia are almost never in the majority of those seen in sleep disorders centers, in spite of...