A provincial study suggests that visits to the ER for gambling problems after the launch of the online market rose, and the rate was 154% higher than expected by mid-2025
Ontario’s expansion of online gambling was followed by a sharp rise in emergency department visits linked to gambling disorders.
A population study published this week in the American Journal of Preventive Medicine tracked more than 17.3 million Ontario residents from January 2012 through June 2025.
Researchers identified 952 gambling disorder emergency visits involving 757 people during that period. The average quarterly visit rate was 31.3% higher after market liberalisation than before it.
The increase did not occur immediately after Ontario opened its regulated private online market in April 2022. Instead, the rate began climbing by 7% each quarter.
By the second quarter of 2025, it was an estimated 99% above the level expected from earlier trends.
Young men accounted for much of that change. Among males aged 10 to 29, the rate was 154% higher than expected by mid-2025.
It was 116% higher among men aged 30 to 44. Researchers found no statistically significant increase among women.
Those arriving at emergency departments often had problems extending beyond gambling. Mental health or substance use conditions appeared in 72.1% of visits.
Major depression was recorded in 33.3%, while acute stress reactions appeared in 21.8%. Nearly one-third of gambling-related visits led to hospital admission.
Researchers described the cases as severe manifestations of gambling harm, rather than a measure of overall problem gambling.
They also cautioned against assigning the increase to one regulatory change. Ontario’s private market launch overlapped with wider access to legal single-event sports betting. The study therefore measured their combined effect rather than separating the two.
Ontario market sees rapid expansion
Ontario introduced its private regulated internet gambling market in April 2022. Its growth since then has been substantial.
During the 2024-25 financial year, players wagered C$82.7bn through private operators. That was 32% higher than a year earlier.
Gaming revenue climbed 31% to C$2.9bn. The market ended the year with 50 active operators and more than 2.6m active player accounts.
Casino games remain the largest part of Ontario’s regulated online gambling business. They accounted for the clear majority of wagering during 2024-25.
The scale of that market matters when considering gambling-related harm. Mobile betting gives players continuous access to casino games and sports markets without visiting a physical venue.
Single-event sports betting has also widened the range of products available. In-play betting allows wagers to be placed repeatedly while a sporting event is underway.
Other research points to rising gambling harm
The emergency department findings add to other research examining gambling behaviour since online betting expanded.
A separate Ontario study examined more than 37,000 gambling-related contacts with the province’s mental-health and addiction support service.
Researchers found that contact rates increased substantially after online gambling expanded. The largest increases were again concentrated among younger males.
US research has produced similar warning signs. A 2025 study examining internet searches found increased demand for information related to gambling addiction after sportsbook legalisation.
The increase was particularly noticeable in states offering online sports betting.
The Ontario emergency department study goes further because it measures acute healthcare encounters rather than searches or support-line contacts.
Researchers stressed that emergency cases remain rare. They also noted that many people experiencing gambling harm never seek formal treatment.
That suggests hospital data captures only the most severe end of a much broader problem.