Galen believed that depression came from an excess of black bile. If the black bile became overheated or there was also an excess of yellow bile, mania resulted. He was right about the connection between depression and mania, wrong about bile.
Still, nearly 2,000 years later, the search continues for a quirk of body chemistry to explain mental illness. Chromatography, radioisotopes, the whole panoply of techniques available to the modern scientist have not helped much. The biochemical basis for "functional" mental illnesses remains as elusive as ever.
This is not precisely the conclusion of this book, but almost. The authors try to be sanguine about their speciality, ending with the hope that "biochemistry may indeed contribute significantly to the ultimate solution of the mystery of mental illness." Their book, however, provides little support for optimism. It consists almost entirely of "claims and counterclaims" (the authors' words). Little, if anything, is