There’s an opioid shortage too and for the same apparent reason: the federal government setting limits on manufacturers.

I don't know much about the opioid shortage, but for Adderall it seems to be more complicated than just the quotas.... https://www.bloomberg.com/news/newsletters/2023-02-28/are-adderall-dea-quotas-contributing-to-the-shortage

If a manufacturer asks for an increased quota and the DEA denies it, they have to do so publicly, with a notice. Guess what, no notices.

Another source:

Shortages, particularly of generic drugs, have been a longstanding problem. The industry has consolidated and some manufacturers have little incentive to solve shortages because cheap generics generate thin profits.

https://www.livemint.com/news/world/whats-behind-shortages-of-adderall-ozempic-and-other-meds-in-us-11682897998433.html

And another https://www.painnewsnetwork.org/stories/2023/8/3/fda-and-dea-leaders-call-for-more-adhd-meds-but-ignore-rx-opioid-shortages