New State Report Examines Gambling Prevalence In Maryland

What affects the prevalence of gambling disorders in a given area? Is it access to gambling activities in general, access to a specific type of gambling activity, demographic characteristics, local norms, the presence of an underlying addictive syndrome, or some combination of these factors and others? These questions have been asked for many years and have inspired much debate in both political and academic circles. Studying a question like this requires competent and willing researchers, but also a favorable situation for research.

Unlike clinical trials, people cannot be randomly assigned to live within a certain distance of a casino, to prefer a particular gambling activity, or to have some particular demographic trait. This limitation can be overcome by taking advantage of “natural experiments,” times when some variable in a community changes and researchers can isolate the effect that variable has on the prevalence of gambling disorders in the community.

One such natural experiment will take place in Maryland over the next several years with the legalization of slot machines. The results of the first study measuring baseline disordered gambling in the state has just been released to the public, and further studies will be completed over the next several years to assess the effect (if any) of the addition of slot machines to existing gambling opportunities (Shinogle, Norris, et al., 2011).

The researchers conducted a telephone study of approximately 5,500 residents of Maryland and administered a variety of survey instruments, including 17 questions about lifetime gambling problems from the National Opinion Research Center DSM-IV Screen for Gambling Problems (NODS) (Gerstein, Murphy, et al., 1999). The NODS can be used to diagnose lifetime or past year gambling disorders, or both. A lifetime symptom is one that a person has experienced at any point in their life, as in “Have you ever gambled as a way to escape from personal problems?” The researchers found that 1.5 percent of respondents qualified for lifetime pathological gambling (having experienced 5 or more symptoms in their lifetime), and another 1.9 percent qualified for lifetime problem gambling (having experienced 3 or 4 symptoms in their lifetime). Lifetime prevalence for any individual or age group is always equal to or higher than past year prevalence.

The baseline prevalence rates found in this study are comparable to those found in similar studies, including a study of Maryland by one of the same researchers from 1989 (R A Volberg & Steadman, 1989). The 1989 and 2010 studies both found a prevalence rate for pathological gambling at 1.5 percent. The 1989 study had problem gambling at 2.4 percent while the 2010 study found it at 1.9 percent. These rates are in line with the rates found in large national surveys such as the 1999 meta-analysis of the United States and Canada (1.6 percent lifetime pathological gambling) (H. J. Shaffer, Hall, & Vander Bilt, 1999), and the 2008 National Comorbidity Survey Replication (0.6 percent lifetime pathological gambling) (Kessler et al., 2008).

The ultimate question this study is aimed at answering is what will be the impact, if any, of the expansion of gaming by adding slot machines to Maryland’s racetracks. There are two competing schools of thought that the Maryland experiment will inform. The first is the “exposure” theory that assumes the more exposure people have to gambling activities, the higher the rates of problem and pathological gambling. This theory has begun to give way to a newer “adaptation theory”. Adaptation theory suggests that “after the novelty of initial exposure, people gradually adapt to the risks and hazards associated with potential objects of addiction” (H. J. Shaffer, 2005, p. 1227). Adaptation theory sees the rise in gambling problems that had been previously viewed as evidence of the exposure theory as a temporary “bump” that will decrease as the community adapts to the stimulus. We discussed one example of this pattern of bump and decline in gambling among Minnesota youth in aFebruary Gambling Disorders 360˚ blog post.

The researchers conducting the current study suggest that the rates of problem gambling may rise “three- or four-fold,” though it is not clear from the study where this prediction comes from (Judith Shinogle, Norris, et al., 2011, p. 9). The paper makes reference to three studies that found an increase from .8 to 1.3 percent (H. J. Shaffer et al., 1999), a doubling (D. Gerstein, Murphy, et al., 1999), and a 90% increase in gambling problems (Welte, Wieczorek, Barnes, Tidwell, & Hoffman, 2004), for an average increase of about 80%, well below the 200-300% increase predicted by the authors.

Only time will tell if new gambling opportunities will impact gambling problems in a state that already has access to local racetracks, a lottery and casinos in bordering states. We look forward to the results from Maryland’s natural experiment and what they tell us about exposure and adaptation.

The full study isavailable for downloadon the University of Maryland Baltimore County’s website (the link goes directly to the study PDF). Do you have thoughts or questions about this research? Let us know in the comments section below!


Gerstein, D., Murphy, S., Toce, M., Hoffmann, J., Palmer, A., Johnson, R., Larison, C., et al. (1999).Gambling Impact and Behavior Study: Report to the National Gambling Impact Study Commission. Chicago: National Opinion Research Center.

Kessler, R. C., Hwang, I., LaBrie, R., Petukhova, M., Sampson, N. A., Winters, K. C., & Shaffer, H. J. (2008). DSM-IV pathological gambling in the National Comorbidity Survey Replication.Psychol Med,38(9), 1351-60. doi:S0033291708002900 [pii] 10.1017/S0033291708002900

Shaffer, H. J. (2005). From disabling to enabling the public interest: natural transitions from gambling exposure to adaptation and self-regulation.Addiction,100(9), 1227-30; discussion 1235. doi:ADD1200 [pii] 10.1111/j.1360-0443.2005.01200.x

Shaffer, H. J., Hall, M. N., & Vander Bilt, J. (1999). Estimating the prevalence of disordered gambling behavior in the United States and Canada: a research synthesis.American Journal of Public Health,89(9), 1369-76.

Shinogle, J., Norris, D. F., Park, D., Volberg, Rachel A., Haynes, D., & Stokan, E. (2011).Gambling Prevalence in Maryland: A Baseline Analysis(p. 55). Baltimore, MD: Maryland Institute for Policy Analysis & Research.

Volberg, R A, & Steadman, H. J. (1989). Prevalence estimates of pathological gambling in New Jersey and Maryland.The American Journal of Psychiatry,146(12), 1618-1619.

Welte, J. W., Wieczorek, W. F., Barnes, G. M., Tidwell, M.-C., & Hoffman, J. H. (2004). The relationship of ecological and geographic factors to gambling behavior and pathology.Journal of Gambling Studies / Co-Sponsored by the National Council on Problem Gambling and Institute for the Study of Gambling and Commercial Gaming,20(4), 405-423. doi:10.1007/s10899-004-4582-y

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