Mogens Schou’s My Journey with Lithium, written on the invitation of Johan Schioldann

Paul Grof’s comments on Barry Blackwell’s additional comments


More hindsight thoughts

        Barry Blackwell’s two sets of comments (2019a,b) on Mogens Schou: My journey with lithium revisit events that happened five decades ago. It’s helpful to look at the happenings, in hindsight, to see what we can still learn.

        While incorrect, Blackwell and Shepherd’s 1968 critique of lithium studies (Blackwell and Shepherd 1968) was beneficial and served a crucial function. I had stated that repeatedly. At that time, Mogens Schou, Jules Angst and I wavered to proceed to a placebo test of our findings. Without Blackwell and Shepherd’s article, a strict placebo test and the subsequent introduction of lithium into stabilizing bipolar treatment may have been delayed for a long time. Many bipolar patients would have missed stability.

        As Leonardo Tondo correctly stresses (Tondo 2019) our intense hesitation to conduct a double-blind discontinuation trial was based on concerns about patient well-being. Patients included in our open studies were not like patients who nowadays start taking lithium after a brief illness. The several hundred patients included in the open evaluation (Baastrup and Schou 1967; Angst, Grof and Schou 1970) had often been sick for countless years before starting lithium; many had also attempted suicide. While on lithium, they remained in remission for the first time in their life.

        Convincing such patients to enter a discontinuation trial with placebo was important for science, but for patients the participation was dangerous or possibly disastrous. This dilemma was much greater than in the usual double-blind studies. In particular, Mogens Schou’s compassion for manic depressive patients was profound. As I wrote earlier: “Upon receiving one of many awards, he said: ‘For me, every single patient whose life was changed radically by lithium outweighs honors and awards. I trust that you understand and agree. . .’” (Grof 2006).

        Had it not been for the biting criticism of the 1968 “Myth” article, the double-blind discontinuation (Baastrup et al. 1970) may not have been initiated. Yet, it was the strongly positive result of the blind discontinuation study that started altering the previously negative view of lithium. It has triggered the official approvals. Moreover, the use of sequential analysis made it possible to terminate the experiment after a mere six recurrences on placebo.

        As I understand Barry Blackwell’s comments, their concern about the absence of double-blind studies was prompted by many uncritical clinical reports that afterwards failed the double-blind tests. Blackwell and Shepherd concluded that the only way to eliminate bias, false optimism and unfounded enthusiasm was via a placebo-controlled double-blind study.

        One also needs to appreciate the context: The 1960s was a golden era of introducing double-blind studies into psychiatry en masse. For instance, in our psychopharmacological department, Psychiatric Research Institute in Prague, the enthusiasm went so far that all psychotropic medications had only experimental numbers; none had an identifying label.

        As researchers, we all are bound to make mistakes, but we react to them differently. I remember vividly that when I met Barry for the first time, much to his credit, he without hesitation conceded that their conclusions were unjustified. What a sharp contrast with Michael Shepherd who was later asked on various occasions about their 1968 article. I never heard him admit that he made a mistake.

        In hindsight, I feel that I have learned two relevant, methodological lessons. First one was pointed out in several explorations. If one investigates changes in the bipolar course using mirror image method, and wants to arrive at interpretable, replicable findings, the patient sample must exceed about 100. The size must make up for the large individual variability of the course (Grof 1994).

        Missing this point led Blackwell and Shepherd to one wrong conclusion that unfortunately Barry reiterates in his comments here: “Seldom acknowledged in the ensuing debate was the fact that we demonstrated equivalent efficacy for imipramine using the same statistical methodology on a small sample of bipolar patients from the Maudsley database.” I believe Barry is referring here to a report on13 Maudsley patients published by Saran (1968). On the other hand, our cohorts included more than 250 patients.

        Second, double-blind placebo-controlled trials are vital but not a panacea. Such trials are necessary for most of the problems in psychopharmacology, but at times they are not essential or feasible. Schou, for example, compared the results of open and double-blind trials carried out with lithium stabilization and the findings were indistinguishable. Presumably, it depends on the severity and type of pathology one assesses.

        Similarly, when dealing with issues such as pregnancy or mortality, one cannot use a double-blind methodology yet must answer vital clinical questions by compiling relevant observations. In addition, the double-blind method does not always provide the correct answers. Misapplied, for example, to very heterogeneous samples, it may offer misleading conclusions.



Angst J, Weis P, Grof P, Baastrup PC, Schou M. Lithium prophylaxis in recurrent affective disorders. Br. J. Psychiatr. 1970;116:604-14.

Baastrup PC, Schou M. Lithium as a prophylactic agent. Arch. Gen. Psychiat. 1967;16:162-72.

Baastrup PC, Poulsen JC, Schou M, Thomsen K, Amdisen A. Prophylactic lithium: Double-blind discontinuation in manic-depressive disorders. Lancet 1970;II:326-30.

Blackwell B, Shepherd M. Prophylactic lithium: Another therapeutic myth? An examination of the evidence to date. Lancet 1968;I:968-71.

Blackwell B. The lithium controversy: a historical autopsy. June 19, 2004.

Blackwell B. Barry Blackwell’s comment (Mogens Schou: My journey with lithium). March 21, 2019a.

Blackwell B. Barry Blackwell’s additional comments (Mogens Schou: My journey with lithium). June 6, 2019b.

Grof P. Mogens Schou (1918-2005): Obituary. Neuropsychopharmacology 2006;31:891-2.

Grof P. Designing long-term clinical trials in affective disorders. J Affect Disord. 1994;30(4):243-55.

Saran, BM. Prophylactic lithium? Lancet. 1968;2(7562):284-5.

Tondo L. Leonardo Tondo Comment. (Mogens Schou: My journey with lithium). February 7, 2019


October 31, 2019