Citing Hippocrates on depression in epilepsy

When writing about the bidirectional etiological relationship between depression and epilepsy, neuropsychiatrists often cite Lewis (1934) [Lewis AJ. Melancholia: a historical review. Journal of Mental Science 1934; 80: 1-42] who cited Hippocrates - namely, "melancholics ordinarily become epileptics, and epileptics, melancholics". In this paper, the complicated reference for this citation from Lewis (1934) was critically reappraised.

The Greek-Latin edition of Hippocratic writings by Ermerins to which Lewis (1934) referred and most volumes of the standard Greek-English edition of the Hippocratic writings in The Loeb Classical Library were freely available as facsimile pdf documents in the Internet Archive (archive.org).

Melancholia (i.e., "the black bile disease") is defined as a persistent mental state of fear and sadness ("Aphorisms", section 6, aphorism 23) which appears more consistent with a dysthymic disorder or depressive personality disorder than an acute (episodic) depressive disorder. Confusingly, the term melancholia also signifies a humoral etiology, namely a surplus of black bile, which causes several distinct diseases including epilepsy (aphorism vi/56). The quote addressing the conversion of melancholia into epilepsy and vice versa was taken from the writing "Epidemics" (book 6, section 8, paragraph 31). The famous treatise on epilepsy, "De Morbo Sacro", does not mention melancholia but instead, attributes epilepsy to two other humors: phlegm and (yellow) bile. This writing proposes an etiological relationship between (inherited) personality and epilepsy, wherein a phlegmatic temperament represents an epilepsy risk while a bilious (choleric) temperament offers protection against epilepsy.

With only a few clarifications, the neuropsychiatric quotation from Hippocrates and the reference to Lewis (1934) could generally be approved as appropriate. However, the proper framework of the quote seems to be personality and not mood. A more precise reference to a standard edition of "Epidemics" book 6 is also suggested.