OK, a note on this since one of the things I do/have done is drug testing.
I'm not sure how I would describe it but let me lay out the observed data from the multiplied thousands upon thousands of drugs tests I've run:
a) it has been VERY rare to find a person positive for one "illicit" drug without them also being positive for THC (note: yeah, I get positive Barbiturate tests or TCA anti-depressants that may be prescribed but (for example) it is next to never that I get a positive cocaine result but negative for THC.
b) that, of course, begs the question, "But how do you know they STARTED with THC," which is a good question. In the cases where I've done review and had access to prior data, I can find many cases of someone who (say) 3 years ago had a positive THC only and now both, but I've yet to find pos COC three years ago but negative THC. It would require more microanalysis than I can possibly do to validate this better.
c) it is not uncommon to see Patient A was positive for THC only three years ago and now is on four different things.
d) the number of opioid positive tests has gone up God knows how many times (10? 15?) in the last 12 years when I began sort of noticing trends. Meth use was rising for a long time but at least appears to have leveled off.
Again - don't say "you're saying X." I don't think we can take something like this down to a bumper sticker slogan that we can throw out there to answer all criticism. All I'm basically saying is that is has been my observation reviewing (and performing) drug testing in a suburb of one of the largest cities in the USA that it appears more likely than not that if a person is positive for "another" drug (most specifically COC and OPI) in the panel, they are positive for THC as well - and for those repeat patients, you can find (more often than not - again) they used THC and added the others.
I've seen my share of drug screens over the years and agree with your description generally.
Yes, I know it's not a "controlled" study" yadda yadda but just take that for what it's worth.
Every other chemist/med tech I've spoken with the last 15 years has observed the exact same thing (when we discuss it - which is rare).
I think we would agree that the social acceptance of drugs goes something like:
1. Rx'd drugs like opioids and benzos
2. alcohol (and maybe switch up the top two or three here)
3. weed
4. probably something else
5. tobacco
6. other stuff
Point being that the trend is from greater socially acceptable drugs trending toward less socially acceptable drugs.
And the top first psychoactive drug by far is alcohol. Most do go through tobacco, alcohol, and cannabis before ever getting to the harder drugs. And although Rx drugs get a bad rap you have to get to 5th or 6th choice drugs before the majority have used Rx opioids, benzos, or stimulants - all of which have become demonized of late.
My point was centered on cannabis being singled out as a gateway drug when alcohol is really the first drug most use. In reality, cannabis is just the first semi-illicit drug most people use. In fact, it's completely legal here on the state level and the social acceptability of it continues to grow. In places where medical and/or recreational is allowed its use is not automatically seen as "abuse" simply based on use. Many real honest to God Almighty healthcare professionals recommend people use it medically, both in low and high THC varieties.
To that: A funny dispensary story. I went to a dispensary in Reno and they were having a little trouble with our registration process so I was called back up to the window. As I stood there waiting an elderly couple walked in - they looked to be in their seventies. The very prim and proper lady came up to the window and said her doctor had recommended she come off her opioid (she may have mentioned tramadol or something else - can't remember) and begin using cannabis (she may have said CBD, just to be as specific and fair as I can be - but even low THC products contain THC, just in very low amounts that are often enough to trigger a positive UDS). That country song "Everybody's gone country (but with cannabis substituted)" popped into my head.
Back to alcohol, it's legal in all 50 states despite being psychoactive and by the time even a chronic abuser gets to the facility it's often not detectable, even if we did check (which we often did in the ER for various reasons).
I've found that most, if not very close to all, who go on to use the harder drugs have a history of mental illness and/or abuse. We don't spend nearly the public money on that as we do drug enforcement. Misplaced priorities in my book.
I never argued that most don't try cannabis before the harder drugs, but I do question the gateway drug theory as the reason for that (and besides, where does alcohol fall in that argument?). There are more variables in play: h/o abuse or mental illness, social acceptability, and others. The gateway drug theory is more a model based on criminality, the assumptions being that using one illicit substance makes one more likely to use another (but what about states where it's legal?) and that users go looking for a more and more intense effect. I look at it more from a medical/health perspective, which is not terribly concerned with the legal arguments aside from the well-being of the whole person.
And what of the people who use alcohol or cannabis or tobacco and never go on to use harder drugs?
From the National Institutes of Health National Institute on Drug Abuse:
"
These findings are consistent with the idea of marijuana as a "gateway drug." However, the majority of people who use marijuana do not go on to use other, "harder" substances. Also, cross-sensitization is not unique to marijuana. Alcohol and nicotine also prime the brain for a heightened response to other drugs52 and are, like marijuana, also typically used before a person progresses to other, more harmful substances.
It is important to note that other factors besides biological mechanisms, such as a person’s social environment, are also critical in a person’s risk for drug use. An alternative to the gateway-drug hypothesis is that people who are more vulnerable to drug-taking are simply more likely to start with readily available substances such as marijuana, tobacco, or alcohol, and their subsequent social interactions with others who use drugs increases their chances of trying other drugs. Further research is needed to explore this question."
https://www.drugabuse.gov/publications/research-reports/marijuana/marijuana-gateway-drug
If these drugs are gateways then why don't the majority go on to harder substances?
It's my opinion that the gateway theory and emphasis on it is a simplistic explanation that stands in the way too often of getting to the real root causes and therefore the solutions for better health, physical and mental. In any case, it is a gateway (just using the terminology and not giving a stamp of approval) in a minority of people who use cannabis.
To be clear, I understand you are not making the argument that it is a gateway. You are simply noting your observations. My experience is similar, though I often do not have access to old data. You'd have to look hard to find someone who does not see the same progression in the majority of cases (in which case I'd have questions).
Out of curiosity, are you able to mentally retrieve Mrs. Smith's INRs for the last 5 years?
Half joking, but still curious.
ETA: The gateway drug theory does little to nothing to help guide treatment for those who use drugs. It is therefore of little to no use to me in practice aside from counseling to avoid harder drugs that may be more problematic from both health and legal perspectives.
