During the past three decades, legalized gambling revenues in America have ­exploded. Commercial and Indian casinos and state ­lotteries now collectively rake in about $100 billion in profits annually.

In its upcoming term, Congress will be weighing a variety of gambling-related measures, including some that would spur that growth and others that might slow it down. And lawmakers also may be getting closer to passing a measure that for the first time would give a federal agency the authority to begin studying the “harmful consequences” of gambling addiction.