A pathognomonic symptom of bipolar disorder

To the Editor

In the letters pages of ANZJP, April 2012, Pek Ang proposes “extremes in the speed of thought” as a pathognomic symptom for bipolar disorder and goes on to suggest that “we could consider the slower pole of depression as ‘psycho-retardation’ and the faster pole of mania as ‘psycho-acceleration’”. He then queries whether “these ideas have been previously expressed”.

In response to his question, I made what I think is a substantially similar suggestion in an article titled “The Classification of the Functional Psychoses” (Ollerenshaw, 1973). I have excerpted the relevant paragraph from page 527 of that issue, as follows:

“Although most authorities seem to accept that the primary feature of the affective psychoses is the mood change – either elation or depression, it is probably true that most psychiatrists have seen the occasional case which they unhesitatingly diagnose as mania in which the mood is not elated; and, similarly cases of endogenous/psychotic depression in which depression of mood is not one of the patient’s main symptoms – Schneider’s “depressio sine depressione” (Schneider, 1939). In the present writer’s experience, however, there is one of Henderson and Gillespie’s (1927) triad of symptoms which is invariably present in florid manic or depressive psychoses – increased or decreased (retardation) psychomotor activity. That being so, it would seem a logical step to assume the existence in the brain of some ‘pacemaker’ whose function can be ‘accelerated’ or ‘retarded’ in some way to cause increase or decrease in psychomotor activity and other effects – on speed of thinking processes (to produce pressure of speech or poverty of thought)….”