This is the example I'm shocked more people don't invoke in these discussions. Gambling addiction is indisputably real, and slot machines (or craps tables or the ponies down at the track) don't even have stick a needle in you to get you hooked. Actions and reactions are more than enough.

Compulsive overeating relies on the same behavioral/reward mechanisms, with the added bonus of food being something you do physically ingest in the process.

Gambling addiction also has the highest suicide rate among addictions, so definitely serious. The Atlantic had an article recently arguing that allowing sport gambling in the USA was a mistake, imposing huge costs on the most vulnerable.

It’s also popular in other forms these days. Wallstreetbets options gambling, most of crypto, the way many people are “trading” these is purely gambling with some bro-astrology.

When I was a poor teenager I was gambling online and it is an incredible way to lose money unlike anything. With the click of a button you can throw $100 or $1000 into the void- and you often follow it up until your account is empty. Hard to do with many other substances.