Mental Illness and Suicide Risk Drive Hospitalization in Gambling Disorder

Gambling disorder has long been treated as the quiet addiction, a behavioral condition that ruins finances and relationships while rarely announcing itself in hospital records. A new retrospective matched case-control study from Quebec, published in the International Journal of Mental Health and Addiction, now provides one of the most detailed pictures yet of which patients with gambling disorder end up in hospital beds, and why. Drawing on administrative health data linked to addiction treatment center records, the research team led by Ovidiu Tatar and Marie-Josée Fleury of the Douglas Hospital Research Centre and McGill University found that comorbid mental disorders, suicidal behavior, and substance-related disorders tower above all other predictors of hospitalization, while certain patterns of outpatient care appear to shield patients from it.

The scale of the analysis is notable. The cohort consisted of patients recruited from addiction treatment centers across Quebec in 2012 and 2013 who received a diagnosis of gambling disorder at any point between 2009 and 2022. The investigators linked these clinical records with provincial health administrative databases, allowing them to track diagnoses, service use, and hospitalizations over more than a decade. Using the discharge date from each patient’s last hospitalization carrying a gambling disorder diagnosis as the index date, they identified 470 hospitalized patients and matched them by age and sex to 1,606 patients with gambling disorder who had never been hospitalized. Controls qualified only if they had received their gambling disorder diagnosis within the three years preceding the index date, a constraint designed to ensure that the two groups were genuinely comparable in the recency of their diagnosis.

Methodologically, the study relied on conditional logistic regression stratified by age and sex, a technique appropriate for matched case-control designs because it compares each case with its matched controls while automatically accounting for the matching variables. The models produced adjusted odds ratios, a statistical measure expressing how much each factor changes the odds of hospitalization after controlling for everything else in the model. This approach matters because hospitalization in psychiatric populations is rarely the product of a single cause; it emerges from an interplay of illness severity, treatment history, social circumstances, and the way health systems respond to crises. By separating these strands statistically, the researchers could ask which factors carry independent weight.

The answer, in descending order of magnitude, was striking. Patients with comorbid mental disorders in the three years before the index date had nearly ten times the odds of hospitalization compared with those without such comorbidity, an adjusted odds ratio of 9.81. Suicidal behaviors more than doubled the odds, at 2.88, and comorbid substance-related disorders raised them by more than half, at 1.58. These figures align with a growing international literature. A Finnish nationwide register study published in Addiction in 2024 documented elevated somatic and psychiatric comorbidity among people with diagnosed gambling disorder, and a systematic review and meta-analysis in the Australian and New Zealand Journal of Psychiatry found psychiatric comorbidity to be the rule rather than the exception among treatment-seeking problem gamblers. Research from Denmark has similarly linked gambling disorder treatment with heightened comorbidity, criminality, and healthcare costs.

The suicide signal deserves particular emphasis. Gambling disorder carries one of the highest suicide rates of any addiction, and studies of treatment samples in Austria and national inpatient data in the United States have repeatedly documented elevated rates of suicidal ideation and attempts among people with gambling problems, especially when depression is present. The Quebec findings quantify this danger in service terms: a history of suicidal behavior in the preceding three years nearly triples the odds that a patient with gambling disorder will require hospitalization. For clinicians, this suggests that suicide risk assessment should be a routine, systematic component of every encounter with a patient receiving treatment for gambling disorder, not an occasional add-on reserved for obvious crises.

Service use patterns in the year before the index date also proved predictive. High emergency department use carried an adjusted odds ratio of 2.45, and any hospitalization in the prior year raised the odds by 79 percent. These findings echo a broader pattern documented in patients with substance-related disorders, where frequent emergency department visits and prior hospitalizations reliably flag patients at risk of subsequent acute care. Emergency departments, in this sense, function as early warning systems, but also as symptoms of a system under strain. Studies of frequent emergency department visitors have shown that these patients often report unmet primary care needs, suggesting that heavy emergency use reflects gaps in community-based care rather than simply greater illness. The Quebec data now extend that insight to the gambling disorder population.

Perhaps the most actionable findings concern what protects patients. High-intensity outpatient care in the year before the index date halved the odds of hospitalization, with an adjusted odds ratio of 0.50, and high continuity of care reduced the odds by 26 percent, at 0.74. Continuity of care, a concept with a long history in health services research dating back to work on primary care in the 1970s, refers to the extent to which a patient sees the same providers or a coherent team over time rather than a rotating cast of strangers. Research on patients with serious mental illness has shown that family practice continuity reduces unplanned hospital use, and studies of general practitioner regularity have linked it to lower rates of high-use hospitalization. The Quebec study demonstrates that the same principle applies to behavioral addiction: patients whose outpatient care is intensive and consistent are markedly less likely to crash into the acute care system.

Sociodemographic factors added their own texture. Unemployment raised the odds of hospitalization by 45 percent, and living in semi-urban or rural areas increased them by 51 percent, a pattern that likely reflects both the socioeconomic stress associated with joblessness and the thinner supply of specialized addiction services outside major urban centers. Intriguingly, living alone was associated with lower odds of hospitalization, at 0.61, a counterintuitive result the authors note as significant. One possible interpretation is that patients living alone who reach treatment may differ systematically from those with co-residing partners or family, or that cohabiting patients are more often pushed into care by distressed relatives at moments of crisis that otherwise might have escalated to hospitalization. The authors frame the overall picture through the lens of vulnerability: unemployment, rural residence, and social isolation mark patients whose clinical needs intersect with limited community support.

The study’s framework draws on Andersen’s behavioral model of health services use, a foundational framework in health services research that organizes predictors into predisposing, enabling, and need characteristics. This theoretical scaffolding helps explain why both clinical severity and service system factors appear side by side in the results. Gambling disorder, classified as a behavioral addiction in both the DSM-5 and the ICD-11, remains frequently underdiagnosed and undertreated, partly because of stigma. Research on perceived social stigmatization of gambling disorders shows that stigma deters help-seeking and shapes how patients and professionals view treatment, while systematic reviews of general practitioners’ management of gambling disorder reveal persistent gaps in knowledge and screening. Patients may therefore cycle through primary care and emergency departments with depression, anxiety, or substance problems while the underlying gambling disorder goes unrecognized.

The Lancet Public Health Commission on gambling, published in 2024, framed gambling as a significant and growing public health concern, and the Quebec study adds a concrete service-delivery dimension to that call. The authors’ conclusion is direct: the key clinical needs and vulnerabilities among patients with gambling disorder should be addressed through outpatient interventions that prioritize high continuity and intensity of care. In practical terms, that means building treatment pathways in which a patient with gambling disorder sees a stable, coordinated team that can manage comorbid depression, screen for suicide risk, treat concurrent substance use, and maintain contact over time, rather than relying on episodic crisis-driven care. The chronic disease management model long advocated for addiction, which treats addiction as a relapsing condition requiring sustained monitoring rather than a discrete episode to be cured, fits these findings closely. As jurisdictions worldwide expand legalized gambling and online platforms multiply access, the population of diagnosed patients will likely grow, and the Quebec data offer a template for identifying, early and precisely, those most at risk of hospitalization, and for designing the outpatient systems that could keep them out of hospital beds altogether.

Subject of Research: Clinical, service use, and sociodemographic predictors of hospitalization among patients diagnosed with gambling disorder in Quebec, Canada.

Article Title: Predictors of Hospitalization Among Patients with Gambling Disorder: a Retrospective Matched Case–Control Study

Article References: Predictors of Hospitalization Among Patients with Gambling Disorder: a Retrospective Matched Case–Control Study. (n.d.). https://doi.org/10.1007/s11469-026-01729-w

Image Credits: AI Generated

DOI: 10.1007/s11469-026-01729-w

Keywords: gambling disorder, hospitalization, comorbid mental disorders, suicidal behavior, substance-related disorders, emergency department use, continuity of care, outpatient treatment, case-control study, Quebec, behavioral addiction, health services research