I just found this fascinating aside on Sherlock Holmes in a 1973 paper on amphetamine psychosis, suggesting that the cocaine-using Holmes displayed the classic repetitive behaviour often seen in frequent users of dopamine-acting stimulants.
The paper discusses what was known about the pharmacology of amphetamine in the early 1970s and how it relates to psychosis, but starts with an excellent description of the effects of chronic speed use.
One of these constellations involves an intense feeling of curiosity, often manifested by repetitious, stereotyped examining, searching, and sorting behaviors. This repetitious activity has been variously called “punding”, “hung-up activity”, “obsessive-compulsive tendencies”, and “knick-knacking” (by inhabitants of the Haight-Ashbury scene).
Its characteristic feature is engagement in tasks that primarily involve small bits or minutiae and a marked enhancement of perceptual acuity directed toward these minute objects. At times there are perceptuo-motor compulsions, manifested as repetitious stringing of beads or as acts of arranging, sorting, and lining up pebbles, rocks, or other small objects. Most of the so-called “speed art” is replete with complicated syntheses of a multitude of minute details, often depicting universal themes or mandalas. Speed users are frequently observed taking apart such objects as television sets, watches, radios, and phonographs.
Subsequently, the parts may be analyzed, arranged, sorted, filed, and cataloged and, rarely, put back together. Many patients report a sense of satisfaction associated with this compulsive-like conduct. Perhaps the best-known example of searching and examining behavior is that of Sherlock Holmes, whose cocaine habit was described by Dr. Watson:
Finally he thrust the sharp point home, pressed down the tiny piston, and sank back into the velvet-lined arm-chair with a long sigh of satisfaction. Three times a day for many months I had witnessed this performance…
‚ÄúIt is cocaine,‚Äù he [Holmes] said, ‚Äúa seven-per-cent solution… I suppose that its influence is physically a bad one. I find it, however, so transcendently stimulating and clarifying to the mind that its secondary action is a matter of small moment…
‚ÄúMy mind,‚Äù he said, ‚Äúrebels at stagnation. Give me problems, give me work, give me the most abstruse cryptogram, or the most intricate analysis, and I am in my own proper atmosphere. I can dispense then with artificial stimulants. But I abhor the dull routine of existence. I crave for mental exaltation. That is why I have chosen my own particular profession, or rather created it, for I am the only one in the world…
“To the trained eye there is as much difference between the black ash of a Trichinopoly and the white fluff of a bird’s-eye as there is between a cabbage and a potato.” “You have an extraordinary genius for minutiae,” I [Watson] remarked (The Sign of the Four, pp. 610-612).
Holmes’s description of his “grooving on” puzzles and cryptograms and his penchant for magnificent synthesis of details to solve a given case are quite analogous to the amphetamine addict’s intense curiosity and preoccupation with minutiae. Even at a low point in the drug-use cycle, these persons will seek out stimulating mechanical or intellectual puzzles. This compulsion for analysis is widely recognized in the “speed scene.”
Of course, cocaine wasn’t the only drug Holmes dabbled in, as he was also a user of opium and tabacco, but it’s interesting that the author of the paper makes a link between Holmes’ cocaine use, and both his investigative style and ‘knick-knacking’ between cases.