Dropout from gambling treatment in Quebec, methamphetamine as a marker at addiction intake, and a PGSI that monitors populations poorly

November 2, 2026. By Chris Beerman, LCSW, CADC.

Almost half of Quebec gambling-disorder patients drop out of treatment, methamphetamine marks gambling severity at addiction intake, and the PGSI performs poorly as a population monitor.

The week's strongest papers are about the treatment system rather than the gambler: a linked-register cohort from Quebec on who drops out of gambling treatment, and intake data on 9,421 gamblers entering Australian drug and alcohol services. Alongside them, a Rasch analysis asks whether the PGSI should carry Britain's prevalence statistics, and Utah has turned its dispute with Kalshi into a criminal case.

Studies worth reading

Factors Associated with Treatment Dropout Among Individuals with Gambling Disorder: A Retrospective Cohort Study

Journal of Gambling Studies, Canada.

A retrospective cohort of 1,719 patients diagnosed with gambling disorder between April 2009 and March 2021 who had at least one treatment episode at a publicly funded Quebec addiction centre, with centre records linked to provincial health databases. Forty-six percent dropped out of the index episode. Prior dropout was the strongest predictor (adjusted odds ratio 5.65), with bipolar disorder (1.57) and semi-urban or rural residence (1.33) also raising the odds, while treatment lasting more than six months (0.45) and high-intensity (0.62) or regular (0.70) outpatient care lowered them. Administrative data cannot say why anyone left, and the comparison across care intensities is observational. A companion paper by the same group in Administration and Policy in Mental Health follows 907 of these patients for three years and finds that under a third received substantial gambling treatment throughout. Funded by the Fonds de recherche du Québec.

Locating Gambling Severity Within Polysubstance Involvement: The Specific Role of Methamphetamine in 9,421 Adults Entering Treatment

Journal of Gambling Studies, Australia.

Routine intake data from a non-government alcohol and drug provider in Queensland and New South Wales, November 2022 to February 2025: 9,421 of 18,361 adults assessed reported past-year gambling and completed the PGSI, and 34.9 percent of those scored in the high-risk band. High-severity methamphetamine use carried the strongest association with gambling severity (odds ratio 3.66, confidence interval 3.25 to 4.12), broader non-alcohol polysubstance involvement a modest independent one (1.31 per standard deviation), and high-severity alcohol use none once the rest was accounted for. The data are cross-sectional and from one provider, and more than half the sample had used methamphetamine recently. For any addiction service, I read it as a case for routine gambling screening at intake, with a methamphetamine presentation as a reason to be more careful, not less. Free full text; the first author works for the provider, and the senior author reports government gambling-research funding.

Player exclusion and sub-market substitution: synthetic DiD evidence from Germany's gambling machine market

Journal of Regulatory Economics, Germany.

Hesse introduced a player exclusion programme for gambling halls in 2014 but not for the restaurants and bars that also host machines. With biennial machine counts for municipalities of 10,000 or more residents from 2002 to 2020 and synthetic difference-in-differences, the authors estimate that the programme removed about 8 machines per municipality from halls and added about 11 in gastronomy venues, with the shift concentrated in towns of 20,000 or more. These are machine counts, not play or harm, so the paper shows where supply moved rather than whether excluded players followed it. It is still the clearest evidence I have seen that an exclusion scheme covering one venue type pushes machines into the type it does not cover. Free full text.

Problems with the Problem Gambling Severity Index (PGSI): Is it fit for public health monitoring of gambling harms? An analysis with Rasch Measurement Theory

Psychology of Addictive Behaviors, United Kingdom.

Pooled PGSI responses from four British national surveys (15,716 people), analysed with Rasch Measurement Theory. The scale performs reasonably well as a clinical screen, with good precision at the clinical threshold, but person reliability for separating low-, moderate- and high-risk groups was low (0.19 to 0.58), the items were too severe for a general-population sample, the scale appeared to measure two things (behaviours and impacts), most items drifted across surveys and two response categories were redundant. The surveys are British and self-completed, and the paper does not test an alternative. For anyone who reports prevalence by PGSI band, as many US state surveys do, the conclusion is that the categories below the clinical cut-off are measured too imprecisely to track. Funded by GambleAware.

Sports Betting, Lotteries, and State Revenues in the Post-PASPA Era

Public Finance Review, United States.

Monthly lottery sales from 18 states in a staggered difference-in-differences design that uses the state-by-state timing of sports betting legalization after 2018. The authors find no economically or statistically significant effect of sports betting on lottery revenue, across specifications and sub-samples. The paper is paywalled and its abstract names neither the period nor the states. It sits awkwardly beside a June working paper by Coombs, Madonia, Nencka and Smith, which used annual net lottery revenue from 42 states for 2012 to 2023 and found a decline of about 10 percent after legalization. Outcome, states and years evidently matter, and a legislature weighing its lottery's exposure should ask about all three.

Wagering on Unfinished Experiments: Prediction Markets and Clinical Trial Integrity

JAMA, United States.

A Viewpoint from authors at Duke and UT Southwestern, among them the former FDA commissioner Robert Califf, on Kalshi's July announcement that it would list contracts on clinical trial results and FDA decisions, including whether a phase 3 trial of mirodenafil in early Alzheimer disease meets its primary endpoint. Kalshi opens trading only after enrolment closes, requires users to attest that they are not trial personnel and bans trades on material nonpublic information. The authors' objection is that enrolment closing is not the trial ending: follow-up data are still being collected, participants never consented to outsiders betting on their treatment courses, and public odds can become part of the experiment they claim to forecast. It is an argument rather than a study, and the full text is paywalled, so I have not seen the policy actions it calls for.

Policy and public health news

Utah ups the ante in Kalshi gambling fight with felony charges Utah's attorney general charged Kalshi and co-founders Tarek Mansour and Luana Lopes Lara on October 28 with 13 felony counts and a misdemeanour, most of them for online gambling promotion, two days after the CFTC sued Utah to halt the state's civil case.
Polymarket, Kalshi, Nadex sue Louisiana, Missouri, Utah Three preemption suits in two days: Kalshi against Missouri's attorney general and gaming commission (E.D. Mo., October 27), Polymarket US against Louisiana's attorney general and gaming board (E.D. La., October 27) and Nadex against Utah's attorney general (D. Utah, October 26).
Kalshi Inc. v. Ho-Chunk Nation (Seventh Circuit, October 27): order on Kalshi's petition for permission to appeal the Wisconsin ruling that let the Nation's IGRA claims proceed; granted, per reporting citing Daniel Wallach.
Appeal of Win Win Win, LLC (Supreme Court of New Hampshire, October 28): the court affirmed the 2024 ruling that Andy Sanborn was ineligible for the Concord Casino's charitable gaming licence, as reported by NHPR.
Exploring the potential of banking transaction analysis to understand consumers' use of illegal gambling The Gambling Commission's open-banking panel, linked to PGSI scores, finds licensed spending does not fall after someone first pays an unlicensed operator, and that the usual ordering of risk groups is reversed among illegal-market users; not nationally representative.
New Jersey: Rutgers study finds high rate of gambling in those ages 13 to 17 In a survey of 1,677 Americans aged 13 to 27, 42.7 percent of 13- to 17-year-olds had gambled in the past year; 6.6 percent of the full sample had used prediction markets, about 40 percent of them at high risk.
NCPG names Charles Jeffers II interim executive director Effective October 26, after the previous executive director left in September during the controversy over Kalshi's membership; the permanent search begins in January.
Brazil Supreme Court sets out schedule for public hearing on betting ban Justice Luiz Fux will hear 28 entities on November 3 on the provisional measure that bans fixed-odds betting, in the betting association's constitutional challenge.

Also in the index

Forty-one studies entered the index this week, among them a cross-national study of social identification on gambling websites as a correlate of gambling problems, with free full text. All of them, with filters, at gambling-research.com/research; this week's legislative and court activity, including the new Kalshi and Polymarket complaints in Missouri and Louisiana, is at gambling-research.com/bills and gambling-research.com/courts.