I'd bet a 1000-piece mono-color puzzle that close to 50% of currently written software is done on those drugs.
In my 18 years of in-house software dev experience (several countries, companies of different sizes), not once have I even heard (in the real world, not online) of people using any sort of drugs like the ones mentioned in the article.
I'm not saying that you're wrong. But based on my personal experience, I also could bet the opposite of what you're saying and feel just as confident.
Doubly so if they're taking them illegally
I guess it depends on your environment. Silicon Valley seems particularly prone to it.
It would be an interesting study, though.