Elise Lam was taking multiple SSRI / SNRI drugs. The timing and consistency of her intake is unknown. The numbers cited in the inventory of her meds are all over the place - some possibly indicating intake after the prescription date and others showing a surplus above the last prescription amount.
Without knowing whether the set of January 11 prescriptions represented the entirety of her traveling stockpile, it's impossible to know for certain how much she'd taken, much less when she'd taken it.
Even without requiring any over-dosage ...
The potential inter-psychomed and overall inter-med interactions made Lam a prime candidate for Serotonin Syndrome:
https://en.wikipedia.org/wiki/Serotonin_syndrome
https://www.mayoclinic.org/diseases-conditions/serotonin-syndrome/symptoms-causes/syc-20354758
This potentially life-threatening syndrome is triggered by a build-up of excess serotonin. In terms of both cause and effects, it mimics the somatic effects of many hallucinogens.
Agitation, restlessness, and confusion are common symptoms in even a mild occurrence.
Interestingly (in relation to Lam's case) a severe Serotonin Syndrome episode is typically accompanied by hyperthermia / high fever, and whole-body cooling is the recommended treatment for this particular symptom.
Bottom Lines:
- I strongly suspect she was effectively 'tripping' (at least physiologically) during her time at / in the elevator. Whether it was the result of over- or under-intake of her prescribed meds is an open question. The possible involvement of Serotonin Syndrome doesn't even require variance from her prescribed regimen.
- If there had been a triggering event leading to stress and / or over- or under-medication, it may well have had something to do with losing her phone (her comm lifeline) sometime after sending the last email, and probably after her sightings on January 31.
- Such a triggering event is not required for explanatory purposes. If she'd suffered an episode of Serotonin Syndrome, she could have lost the phone as an outcome rather than a contributing cause.
- If the documented February 1 date for the elevator video is correct, she could have been wandering around or hiding within the hotel (upstairs from the lobby, and quite possibly invisible to the staff ... ) for as much as a day while suffering a medication-induced incident. Such a wandering / hiding period of wandering might even have extended for more than a day. After all - the February 1 video is the last evidence, and it doesn't necessarily peg her last day alive.
- I won't go so far as to suggest going out on the fire escape (the only non-alarmed route to the roof) and / or self-immersion in cold water - either or both in response to severe overheating - is solid enough to frame as a theory, but it's an interestingly suggestive factor that conceivably could have been in play.
NOTE: None of this rules out the involvement of someone else during the course of events. If she were in the throes of Serotonin Syndrome, she would have been vulnerable to manipulation / exploitation / whatever.