I have followed Professor Nassir Ghaemi since he published his book The Concepts of Psychiatry.1 Two psychiatrists from Chile translated the book into Spanish in 2008 and I recommended it to the Spanish psychiatric residents working with me at the time (incidentally, in Spanish the title was translated to Psiquiatría: Conceptos). When On Depression was published in 2013, I had recently moved to live and work in Canada.2 I immediately bought and read it (and subsequently recommended to a few of the patients under my care).

Two reviews of OD I noticed as I prepared for this sojourn into Ghaemi's book. One is published in the British Journal of Psychiatry by a senior psychiatric trainee, Alexander Langford, who praised the book, but the review was somewhat austere and dull.3 The other is written by a historian, David Herzberg, and appeared in the Bulletin of the History of Medicine.4 This one is less terse, also sympathetic but takes issue with Ghaemi's attacks on postmodernism and postmodernist thinkers, whom he calls "Pretenders." Herzberg repeats the well-known criticism made by professional historians who dislike other professions invading their field of expertise: Ghaemi is accused of a "proudly Whiggish faith in science" (BHM 629).

The two reviewers do not give justice to OD. This is a book written with great passion and exquisite intellectual rigor. It made me think of what Edmund Gosse said once about style, paraphrasing the French naturalist Buffon: "le style est l'homme même." "To attain this," Gosse goes on to say, "the writer must be sincere, original and highly trained."5 Do not lose sight of these first two adjectives and Ghaemi's scientific expertise, as I shall come back to them in what follows.

Barney Carroll, psychiatrist and an Australian expatriate, once wrote, "To understand depression is to understand psychiatry."6 It is under this statement we can truly appreciate the depth of Ghaemi's thinking and the daunting task he undertakes in his book. In a previous publication he had strongly and eloquently recommended going beyond a pragmatic nosology and thus "taking disease seriously."7 His book OD is therefore the culmination of an intellectual trip that started years ago in which he brings together a pluralistic perspective inspired and based on Karl Jaspers' General Psychopathology and what he has learned from Rollo May, Elvin Semrad, Paul Roazen and, in particular, Leston Havens, who are called his guides.8 Ghaemi's expertise and distilled phronesis, both as a clinician and a researcher, is present throughout the book.

It is obvious that Ghaemi does not shy away from controversial issues; on the contrary, he embraces them with gusto and with a deliberate and uncompromising objective of finding out what is true, reflecting his profound sincerity and love for clear thinking. This is manifestly clear in his diatribe against postmodernism and, in particular, in his chapter on Pharmaggedon.

In dealing with the reception of GP in the United States, Andrés Heerlein and Carlos Cornaglia mention in a laudatory way Ghaemi's recent reintroduction to psychiatry of Jaspersian concepts such as "pluralism," "Transcendence" and "limit situations."9 These authors dedicate a few lines to explain the reasons why GP is still not widely known (or clinically applied) beyond a few psychiatrists of the East Coast including Ghaemi. It could be said that the first German edition of GP came out exactly during the emergence of psychoanalysis and that psychoanalysis became overwhelmingly successful; to make matters worse for GP, Jaspers positioned himself against psychoanalysis. The possible influence on American psychiatry of the publication of its translation by Hoenig and Hamilton in 1963 was thwarted by the emergence of the psychopharmacological revolution and biological psychiatry, and a few years later by the success of what Josef Parnas and Pierre Bovet called "operational psychiatry" (referring to DSM-III and its successive iterations).10

I think that Ghaemi's originality resides, at least in part, in his effort to revitalize Jaspers' pluralism in the face of the ferrous epistemological cage of the DSM classificatory system in general—as it pertains to Psychiatry—and in particular, as it is reflected in his approach to depression. In OD he establishes a distinction between recurrent severe depression as "depression disease" and neurotic and single episode depression as "depression non-disease." This classification sui generis becomes more complex as we get deeper into his book; further, he delves into the issue of manic-depressive illness, in which he enters in a collision course with David Healy. This initial dichotomous classification Ghaemi expanded and covered elsewhere, in a brilliant and conceptually superior article on biological existentialism.11

I have left the issue of Ghaemi's expertise to the end: in an era dominated by evidence-based medicine, the opinion of the expert ranks low in the hierarchy of knowledge. This is ironical because some of the wisest lines of OD can be found in the chapters dedicated to Paul Roazen, Karl Jaspers and, especially, Leston Havens. I think that the historical perspective of Roazen and the clinico-existential approach of Havens enrich Ghaemi's method-based psychiatry, clearly inspired by Karl Jaspers' philosophy and psychopathology. In the current psychiatric landscape of North America, torn apart by two diverging and reductionist perspectives (exemplified in DSM-5 versus research diagnostic criteria, RDC), Ghaemi's vision is the only one that could take psychiatry beyond its transformation into applied Clinical Neuroscience as a famous new employee of Google once suggested:

That the life sciences team at Google would establish a major exploration into mental health is by itself a significant statement—recognizing the burden of illness from psychosis, mood disorders, and autism as well as the opportunity for technology to make a major impact to change the world for the millions affected.12