Now he's worried about the Horseshoe.

"Do you know what that's going to do to the city of Baltimore?" he said. "That is going to [expletive] this city up."

Michael H. Rosen, a recovering gambling addict and social worker at the gambling center, has his own concerns about the new casino.

"It's going to appeal to the people that can least afford it," Rosen said. "The same person who does the scratch-offs is going to do the slot machines," because both provide an instant result, he said.

Rugle, the center's program director, said the message about the dangers of gambling can be difficult to convey to people in economic straits. They're more apt to see gambling not as a problem, but a solution, she said.

Along with the public information campaign, the center — affiliated with the University of Maryland School of Medicine — is studying the prevalence of gambling in neighborhoods near the Horseshoe casino. A survey completed before the opening will be compared with surveys later.

A national study conducted 10 years ago by University at Buffalo researchers found that living within 10 miles of a casino increases the chance of becoming a pathological gambler by 90 percent. However, a follow-up published this year by the same group showed that the prevalence of problem gambling across the country had not changed since 2000, although dozens of casinos have opened in that time.

John W. Welte, the psychologist who led both studies, said one explanation is that the recession meant fewer new gamblers, and fewer people joining the ranks of problem gamblers.

Welte's research group also produced the study last year on disadvantaged neighborhoods as a risk for problem gambling. The study of nearly 5,000 people was one of the largest of its kind and the results were consistent with other work that shows a correlation between disadvantaged circumstances and problem gambling, Welte said.

A study produced by Yale University researchers in 2011 showed that problem gambling also had a racial component. The research showed that black men were twice as likely as white men to have had symptoms of problem gambling in the previous year, and black women were three times as likely.

The American Gaming Association counters that poor people don't make up the bulk of casino customers. It cited the results of a survey conducted for the organization this spring showing that more than two-thirds of casino visitors consider themselves middle or upper-middle class.

The survey also showed that two-thirds of people earning $35,000 a year or less set a budget of up to $100 for their casino visit, and the same percentage said they would not visit a casino in the next year. Only six percent in that income bracket said they would visit 11 times or more.

Bythella Johnson said she doesn't know whether she'll end up trying the slots at Horseshoe. She visited Maryland Live in early August, walking in with a very conservative $50 stake. She won about $300, then lost it all.

"One thing about gambling," she said. "Somebody going to win, but it don't have to be you."

What is problem gambling?

Problem gambling is an informal term for showing symptoms of a gambling disorder, which is included in the most recent edition of the Diagnostic and Statistical Manual of Mental Disorders — the psychiatric handbook — in the same category as addiction to drugs and alcohol. Gambling disorder is defined in the manual — one of several sources that defines the problem — as showing four or more of these behaviors in 12 months:

•Gambling with more and more money to get the same thrill.

•Feeling restless or irritable when trying to cut down or stop gambling.

•Making repeated unsuccessful attempts to cut down or stop gambling.

•Being preoccupied with gambling often.

•Gambling often when feeling distress.

•Going back to gambling to recover losses.

•Lying about gambling losses or frequency.

—•Jeopardizing or losing an important relationship, job or opportunity because of gambling.

•Relying on others for money in financial straits caused by gambling.

Source: The Diagnostic and Statistical Manual of Mental Disorders 5th Edition, or DSM V, published by the American Psychiatric Association, May 2013