US, Canada, and other parts of the world, which hold meetings that adhere to a tradition allowing alcoholics to freely express their doubts or disbelief that spirituality will help their recovery, and these meetings forgo the use of opening or closing prayers. Disease concept of alcoholism More informally than not, AA's membership has helped popularize the disease concept of alcoholism which had appeared in the eighteenth century. Though AA usually avoids the term disease, 1973 conference-approved literature said "we had the disease of alcoholism." Regardless of official positions, since AA's inception, most members have believed alcoholism to be a disease. AA's Big Book calls alcoholism "an illness which only a spiritual experience will conquer." Ernest Kurtz says this is "The closest the book Alcoholics Anonymous comes to a definition of alcoholism." Somewhat divergently in his introduction to The Big Book, non-member and early benefactor William Silkworth said those unable to moderate their drinking suffer from an allergy. In presenting the doctor's postulate, AA said "The doctor's theory that we have an allergy to alcohol interests us. As laymen, our opinion as to its soundness may, of course, mean little. But as ex-problem drinkers, we can say that his explanation makes good sense. It explains many things for which we cannot otherwise account." AA later acknowledged that "alcoholism is not a true allergy, the experts now inform us." Wilson explained in 1960 why AA had refrained from using the term disease: Since then medical and scientific communities have defined alcoholism as an "addictive disease" (aka Alcohol Use Disorder, Severe, Moderate, or Mild). The ten criteria are: alcoholism is a Primary Illness not caused by other illnesses nor by personality or character defects; second, an addiction gene is part of its etiology; third, alcoholism has predictable symptoms; fourth, it is progressive, becoming more severe even after long periods of abstinence; fifth, it is chronic and incurable; sixth, alcoholic drinking or other drug use persists in spite of negative consequences and efforts to quit; seventh, brain chemistry and neural functions change so alcohol is perceived as necessary for survival; eighth, it produces physical dependence and life-threatening withdrawal; ninth, it is a terminal illness; tenth, alcoholism can be treated and can be kept in remission. Canadian and United States demographics AA's New York General Service Office regularly surveys AA members in North America. Its 2014 survey of over 6,000 members in Canada and the