Frankly, I don’t have a recommendation of what term you should use to describer the workplace drug or alcohol user who presents as a possible threat to the organization. But I do recommend two things...to teach in a DOT supervisor training course. These are recognition of addiction as a classic disease syndrome and helping learners understand tha the terms mentioned above are pretty much all the same thing.
Educate DOT supervisors to see all of these terms as interchangeable when referring to the use of psychoactive substances that are addictive and mood changing.
If they do not learn this upfront during your training, they will play a key role in enabling and confusing others with whom they interact. They will also have weaker documentation, generate diagnostic sounding documentation, and increase risk to the organization from each of these things being pretty worthless because they lack more concrete language that documents what can be seen and experienced.
Many alcoholics have used other drugs, legally prescribed or not, that are addictive. These other drugs also serve as relapse triggers later if they ever seek treatment. And when employee relapse, typically they still look great at work even though they are at-risk for accidents and other horrible drug-related costs.
Side note: I like the terms addictive disease or chemical dependency because they help educate the general public to understand that any mood altering substance is off bounds for those recovering from addictive disease. Any mood altering substance is a relapse. Any employee in a DOT regulated position who goes to treatment for heroin addiction has relapse if they ever pick up a drink of alcohol.
Use of alcohol or drugs begins with experimentation or peer pressure for almost any drinker. Physiologic susceptibility determines from that point forward what the progression of the disease will be. But other factors can influence severity and course of the disease.
The good news is that research shows most people believe alcoholism (addiction) to be a disease, however, this belief does not contribute easily to self-diagnosis because of denial.