More than one in four Medicaid recipients have a diagnosed addiction problem, researchers said this week, and the cost of providing behavioral healthcare and medical care for these individuals runs into the hundreds of millions of dollars annually when compared with Medicaid recipients who don't have alcohol or other drug problems.

A new study from the Substance Abuse Policy Research Program looked at the medical records of about 150,000 Medicaid recipients in six states, and concluded that the 29 percent of patients diagnosed with alcohol or other drug addictions cost these six states alone an extra $104 million for medical care and $105.5 million for behavioral healthcare.

"We found that the medical-care costs for all health problems among those with substance abuse issues are quite significant, which means that there could be a huge cost savings if prevention or early treatment programs were started to improve the health of substance abusers," said Robin E. Clark, Ph.D., associate professor of family medicine and community health at the University of Massachusetts Medical School's Center for Health Policy and Research.

Costs did vary widely from state to state, however, reflecting differences in available behavioral-health treatment services.

General medical costs rose steeply as people with addictions got older, the study found -- even more than costs for addiction and mental-health care.

Researchers attributed this finding to higher rates of illness among older people, the impact of long-term alcohol and other drug use, greater reluctance to seek specialty addiction treatment among this population, and more severe chronic disease among older, addicted patients.

The study, "The Impact of Substance Use Disorders on Medical Expenditures for Medicaid Beneficiaries with Behavioral Health Disorders," was published in the January 2009 issue of the journal Psychiatric Services.