A proposed revision to the definition of addiction by mental health specialists could lead to millions of additional people receiving an addiction diagnosis, The New York Times reports. The changes could lead to big consequences for both health insurers and taxpayers, according to the newspaper.

The revisions are being proposed for the new edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM), scheduled for release in May 2013. The manual would enlarge the list of recognized symptoms for drug and alcohol addiction, and reduce the number of symptoms needed for a diagnosis.

The new manual would include gambling as an addiction for the first time, and may introduce a category called "behavioral addiction—not otherwise specified," that some public health experts say might be used too often to diagnose various addictions, including shopping, video games, sex or the Internet.

The DSM is important because it determines whether insurers, including Medicare and Medicaid, will pay for treatment, and whether schools will finance specific special-education services. The court system uses the DSM to evaluate whether criminal defendants are mentally impaired. Drug manufacturers rely on the manual when making decisions about research.

Some economists predict the new definition of addiction could add 20 million people, leading to additional costs running into the hundreds of millions of dollars.

"The chances of getting a diagnosis are going to be much greater, and this will artificially inflate the statistics considerably," Thomas F. Babor, an editor of the journal Addiction, told the newspaper. He said many people receiving a diagnosis of addiction under the new guidelines would have only a mild problem, siphoning off scarce drug treatment resources in schools, prisons and health care settings.

While the American Psychiatric Association scientific review panel has asked for more evidence to support the revisions on addiction, several researchers involved with the manual noted the panel is unlikely to significantly alter the proposed revisions.