The state regulator said unlicensed sites can bypass self-exclusion and other protections required of Michigan licensees.
The increase was concentrated among younger men, with most gambling-related emergency presentations involving another mental-health or substance-use condition.
The voluntary rules ban youth-oriented imagery, campus ads and risk-free claims, and feed into a new certification programme.
The 126-page commission report targets live wagers, credit cards, autoplay, VIP perks and ad saturation as lawmakers weigh the next step.
The process starts at £5,000 over 24 hours for over-25s and is meant to flag financial distress without affecting credit scores.
A survey of more than 320 gamblers found missed bills and weaker savings were far more common among people betting online than among those betting in person.
Patients averaged fewer than two treatments over 13 years, even as researchers say the disorder often needs long-term care.