This is not a dictionary in the usual sense. Most dictionaries simply define words and phrases at their entry points. Some also explain etymologic origins and indicate pronunciation. Campbell's dictionary can more accurately be described as a one-volume terminologic encyclopedia. Some definitions hold to the brevity expected in a dictionary, but others are, in effect, short articles that include much more than simple definition. For example, the entry for "instinct, death" runs to a column and a half; that for "ion channel" occupies two and a half columns. The book's preface discusses both the advantages and disadvantages of this encyclopedic approach. The main advantage appears to me to be in enabling nonpsychiatrists to benefit from a better understanding of the contextual settings of unfamiliar concepts.

Is a specialized dictionary like this one worth the purchase price for someone who already owns a major comprehensive medical dictionary, such as Stedman's? The value of Campbell's encyclopedic format is pointed out above. The book also has a second value: It defines terms not defined in general medical dictionaries. For example, Stedman's does not define P as the "Rorschach scoring symbol for a popular response" but gives only "symbol for phosphoric residue." Stedman's does not define "paired helical filaments," a characteristic of Alzheimer disease, or "paleophrenia."

This dictionary has other assets. Some of its definitions are more precise than the equivalent definitions in Stedman's; for example, it provides a clearer definition of "incidence," a term often used sloppily in clinical literature. I am personally pleased to see that Campbell has joined some of the rest of us in preferring the nonpossessive to the possessive form of eponymic terms: "Down disease" rather than "Down's disease," "Paget disease" rather than "Paget's disease."

If you frequently read contemporary psychiatric, psychological, or sociologic literature, you should own this dictionary. That it has continued into a seventh edition is probably more convincing praise than I can give. If you own the sixth edition, you should consider buying the new one: Campbell has added more than 2000 new terms and has taken pains to incorporate new terms and diagnostic criteria from the Diagnostic and Statistical Manual IV of the American Psychiatric Association. And for a book of this size and content, its price is eminently fair.