For many problem gamblers, it is not just about the money, but the psychological impact of placing a bet, said Keith Whyte, executive director of the National Council on Problem Gambling. Being entered unwillingly into a vaccine lottery could activate the same parts of the brain that light up when people are gambling, prompting recovering addicts to head back to the casino or other problematic behaviors. “When a state government actively promotes gambling, that creates a mixed message for vulnerable citizens,” Whyte said. “The state has to own that, too.” He said an estimated 2 percent of adults in the United States struggle with gambling addictions. After learning about Maryland’s lottery, Aretz, who lives in Severn, spent a day trying to contact state officials about removing his name from the daily drawings. He found himself wishing he had postponed getting vaccinated so he could have avoided the situation altogether — the exact opposite of what the state intended.