A neurotic hypocondriac of sorts, over the years he took numerous medicines, including trional, philogyne, veronal, dial, opium, adrenalin, caffeine, morphine, evatmine, cola, and others for his ailments.
"Trional frequently has a remarkable effect on the nervous tone. You mention trional, have you any idea what it is?"
"Well... I’ve heard people say that it is a drug to make one sleep."
"You are not answering my question," replied the Professor, who, thrice weekly, at the Faculty, sat on the board of examiners. "I don’t ask you whether it makes you sleep or not, but what it is. Can you tell me what percentage it contains of amyl and ethyl?"
Proust on the power of Veronal on the mind, to wipe out the ridiculous yet retain the sublime:
The moments of oblivion that come to us in the morning after we have taken certain narcotics have a resemblance that is only partial, though disturbing, to the oblivion that reigns during a night of natural and profound sleep.
Now what I find myself forgetting in either case is not some line of Baudelaire, which on the other hand keeps sounding in my ear,
it is not some concept of one of the philosophers above-named,
it is the actual reality of the ordinary things that surround me —if I am asleep—
my non-perception of which makes me an idiot;
it is, if I am awakened and proceed to emerge from an artificial slumber, not the system of Porphyry or Plotinus, which I can discuss as fluently as at any other time,
but the answer that I have promised to give to an invitation, the memory of which is replaced by a universal blank.
from Cities of the Plain, chapter 3 (line breaks added)
However, MP complained that, even after he took the stuff, he still could not sleep.
Some notes from Nietzsche and Gide that pull together a possible connection between Veronal and solitude are here, at the very cool Florilegium site.
MP on his failed attempts to quit caffeine to reduce feelings of paranoia:
For the physical improvement which the reduction of my caffeine effected almost at once did not arrest the evolution of that grief which my absorption of the toxin had perhaps —if it had not created it— at any rate contrived to render more acute.
Dr. Richard Chessick in a review of two Proust biographies (which included the astounding one from 2002 by William C. Carter), points out that MP died shortly after an accidental, self-administered adrenaline overdose.
Carter's bio clarifies that the adrenaline was a dry powder that Proust failed sufficiently to dilute, after he had not slept for a week; that the chemical burned his digestive tract; after which he subsisted on ice cream and cold beer ordered in from the restaurant at the Ritz Paris.
Some possibly relevant info from a neuropharmacologist/neurobiologist on the effects of adrenaline on the recollection of memories is here.
Finally, Carter recounts the testimony of MP's pal, Paul Morand, from his 1949 Le Visiteur du Soir, in which he described the speed freak logic and structure of a typical sentence uttered by MP in spoken conversation. The sentence was like this:
singing, caviling, reasoned, answering objections the listener would never have thought of making, raising unforeseen difficulties, subtle in its shifts and pettifoggery, stunning its its parentheses -- that, like helium balloons, held the sentence aloft -- vertiginous in its length, well constructed despite its apparent disjointedness; as you listened spellbound, you risked becoming enmeshed in a network of incidents that was so tangled that you would have been lulled by its music had you not suddenly been alerted by an observation of unbelievable profundity or brilliant comedy.
MP's written sentences obviously are not dissimilar.
Edmund White's awesome biography of Genet suggests that Proust and Genet revised their drafts (and their thoughts) in a similar way.
When they thought of an adjective, they could sort of "click on" it, to expand it into a phrase. Then they could "click on" the phrase, to expand in into a sentence. Then the sentence could be expanded into a paragraph, etc. It was almost like they could access a system by which their brains worked like a series of embedded hyperlinks, ever circling around, plunging deeper.