Only about one in 10 people who need treatment for addiction to drugs or alcohol receive it, according to a new report. Many who do receive treatment do not receive evidence-based care, according to the National Center on Addiction and Substance Abuse at Columbia University (CASA Columbia).

Many people misunderstand addiction, and think of it as a moral failure or a lack of willpower, instead of a complex brain disease, according to the report, Addiction Medicine: Closing the Gap between Science and Practice. The report finds that doctors are not prepared to intervene or treat addiction, according to The Oklahoman.

“Right now there are no accepted national standards for providers of addiction treatment,” lead investigator Susan Foster, CASA Columbia’s Vice President and Director of Policy Research and Analysis, said in a news release. “There simply is no other disease where appropriate medical treatment is not provided by the health care system and where patients instead must turn to a broad range of practitioners largely exempt from medical standards. Neglect by the medical profession has resulted in a separate and unrelated system of care that struggles to treat the disease without the resources or knowledge base to keep pace with science and medicine.”

According to the report, addiction affects 16 percent of Americans ages 12 and older—about 40 million people. That number is greater than those affected by heart disease (27 million), diabetes (26 million) or cancer (19 million). In addition, 80 million people are considered “risky users,” who use tobacco, alcohol and other drugs in ways that threaten health and safety.

Foster noted that many doctors are not prepared to treat addiction for several reasons. Medical schools’ curriculum generally does not cover addiction, and there is no nationally accepted set of standards for how physicians should treat addiction, she said.