These callers are not alone in their anxieties. Since sports betting on mobile phones was legalized in Massachusetts on March 10, advocates worry that this new form of gambling, so easily accessible in the palm of one’s hand, might lead to an increase in problem gambling in Massachusetts.

“You can now gamble anywhere,” said Rebecca Bishop, director of the Massachusetts Center of Excellence on Problem Gambling Prevention. “You can gamble at home, at school, at work, even treatment programs.”

Still, it’s too soon to know the full consequences of the state’s expanded gambling landscape. The helpline seems to have seen an increase in call volume lately but doesn’t expect to be inundated, said Jen Cyran, managing director of behavioral health at the agency that runs the helpline, Health Resources in Action.

In Ohio, calls to the addiction helpline have tripled in the year since sports betting was legalized. A few years after New Jersey legalized online sports betting in 2018, the prevalence of gambling disorder was found to be three times the rates seen in other populations that had been studied.

In Massachusetts, researchers hired by the Massachusetts Gaming Commission say they expect the effect of legalization to be “modest.” That’s because Massachusetts gamblers were already betting online at rates similar to those in states where sports betting was allowed; they could easily access out-of-state sites, even though it was illegal.

A similar phenomenon occurred when casinos first opened in Massachusetts, according to the researchers. People who wanted to gamble had already been frequenting casinos in Connecticut; the number of gamblers didn’t increase — they just gambled closer to home.

That said, researchers from the University of Massachusetts School of Public Health and Health Science caution that opening the floodgates to mobile betting could draw in new groups of people vulnerable to its allure — such as adolescents, young adults, women, immigrants, individuals in recovery from gambling problems, and college athletes.

Keith Whyte, executive director of the National Council on Problem Gambling, expects Massachusetts “to see an increase in the severity of existing gambling problems and perhaps an increase in the rate of gambling problems.”

But he says he is less worried about Massachusetts because the state “has a statewide plan to address problem gambling. Few other states have that.”

A Public Health Trust Fund funnels a percentage of gambling revenue into efforts to mitigate its harms. The state’s Office of Problem Gambling Services, which started in 2016 within the Department of Public Health, received $12 million from the trust fund this year. The money pays for the helpline as well as prevention and treatment programs.

For the vast majority of people, gambling is a form of harmless entertainment. But for an estimated 1 percent to 3 percent of US adults, it becomes a destructive compulsion. A big win can trigger a powerful feeling that some gamblers yearn to experience again and chase into financial ruin.

Some 97 percent of people who have a gambling addiction already have experienced an addiction to drugs or alcohol or have a mental illness, said Victor Ortiz, director of the state’s Office of Problem Gambling Services.

“People of color are disproportionately impacted by gambling disorder,” said Ortiz, adding that problem gambling is interconnected with a host of other social issues. “The two major risk factors that drive people from recreational stages of gambling to problematic stages are low educational attainment and low economic status.”

Teenagers and young men are of particular concern. “Sports betting may strongly appeal to young boys,” Whyte said. “There’s some evidence that young boys of color are even more likely to bet on sports and develop problems.”

And, cautioned Rachel A. Volberg, the UMass professor who has led the state’s gambling research, “the younger you are when you start gambling, the more likely you are to develop a problem.”

You can tell gambling might be getting out of hand if it stops being fun, and instead makes you irritable and anxious. Other signs are hiding your gambling from family and friends and continuing to gamble despite financial troubles.

In its diagnostic guide, the American Psychiatric Association groups gambling disorder with other addictive disorders, because it involves many of the same features, including compulsively continuing an activity despite the harm it causes. “The same brain mechanism is involved in all these addictive disorders,” Volberg said.

So when people call the state’s gambling helpline, they’re actually calling the same line that Health Resources in Action operates to help people concerned about drug and alcohol addiction. Three years ago, the agency added gambling to its portfolio, and today two-thirds of helpline callers are engaged in gambling. Nearly three-quarters of those who call about gambling are men and the largest age group is 20 to 29.

All the staff members answering the phone are trained to answer questions about either issue. They can guide callers in assessing their risk and direct them to resources, including one of 22 outpatient treatment programs. Another option: voluntary self-exclusion, a program in which gamblers can have themselves barred from gambling for a certain period, or for life.

The numbers of people opting for voluntary self-exclusion “have gone through the roof” among those who want to avoid online betting, said Marlene D. Warner, chief executive of the Massachusetts Council on Gaming and Health. “They may have signed up for an account and quickly realized how overwhelming it can be to be sucked into the excitement of it all,” she said.

Also sucking people in is the ubiquitous advertising for sports betting, some offering deals that can be hard to resist.

“These ads are everywhere. No one can really get away from them,” Bishop said. “I have a 7-year-old — they were coming up on his tablet, which has youth settings on there. … It’s quite scary for people working on this issue.”

Mark Vander Linden, director of research and responsible gaming at the Massachusetts Gaming Commission, said the state’s advertising rules are already among the most rigorous in the country. Still, the commission recently adopted a few of the changes recommended by Attorney General Andrea Joy Campbell, such as requiring operators to strengthen their methods for excluding people younger than 21 and to disclose when an influencer has been paid to endorse a betting platform.

The commission also did a study to characterize what they call “positive play” — gambling behavior that doesn’t cause problems. They identified three characteristics: the willingness to set a limit before starting to gamble; an understanding of how the games work and what the true odds are; and “honesty and control,” that is, a realistic view of gambling’s role in one’s life, and the ability to keep it under control.

If every gambler engaged in this “positive play,” would the operators be able to make a profit? Vander Linden paused, and called that “a difficult question.”

The commission’s mission is to ensure an economic boost for the state and “an appropriate return” for operators — and also to mitigate gambling harms, he said. Vander Linden acknowledged a “tension” between those goals. But he said the commission would work “to the maximum extent that we can” to prevent gambling harms.

Felice J. Freyer can be reached at [email protected]. Follow her on Twitter @felicejfreyer.