Past studies have drawn a correlation between gambling disorder and suicidal behaviors but have yet to establish whether this is a direct cause or is influenced by other outside factors such as genetics and environment. Twin studies are important for looking at causal mechanisms of disease as they allow researchers to tease out the effect of genetics and environment. In an attempt to determine whether gambling disorder (GD) is a causal mechanism for suicidal behaviors, Dr. Wendy Slutske, an ICRG Center of Excellence Grant recipient, and colleagues conducted a twin study utilizing members of the Australian Twin Registry.
Slutske et al., 2022 focused this study on the relationship between precursors to suicide, such as suicidal thoughts, plans and attempts and gambling disorder. Past studies have failed to either prove or disprove a causal link between the two.Twin studies are important to public health because they allow researchers to look at the comparative influences of genetics and environment on a certain behavior.
What did they do?
The researchers assembled two cohorts from the Australian Twin Registry, which included 2,995 complete twin pairs. Two phases of assessments were conducted that gathered information on suicidal behaviors, psychiatric disorders, gambling disorder, income and education. Gambling disorder was assessed by using the National Opinion Research Center DSM Screen for Gambling Problems (Gerstein et al., 1999). Suicidal behaviors were assessed by utilizing a script asking various questions about past suicidal thoughts, plans and actions. The researchers also screened for other psychiatric disorders, including major depression, alcohol use disorder, cannabis use disorder, nicotine dependence and conduct disorder. Socioeconomic status and education level were self-reported by participants. After ascertaining the above information on the twin pairs, the research team performed multilevel discordant-twin analyses to determine whether there was a causal link between gambling disorder and suicidal thoughts, plans and actions.
What did they find?
This study established a significant association between gambling disorder (GD) and suicide thoughts, plans and attempts for the very first time in the peer-reviewed literature. Despite finding an association between GD and suicide thoughts, plans and attempts, researchers were unable to confirm that the relationship is causal in the sample unless they removed the influence of shared genetics and environmental risk factors between the twins. The males within the sample showed a stronger possibility of having a causal relationship between gambling disorder and suicidal thoughts, ideas and attempts than women. . This potential causal relationship may have been related to financial problems related to GD instead of just gambling disorder itself. As a result, the researchers emphasized that using financial harms data to identify individuals having financial hardships may be the best option for targeting, screening and intervening with individuals before they reach suicidal ideation.
The authors reported on the limitations of their current study. They observed that the exclusion of interview questions on other psychiatric disorders such as anxiety, post -traumatic stress disorder and panic order might affect the findings, as these disorders may also affect the presence of suicidal ideation. Next, data collection was retrospective in design, which could lead to some inaccuracies when individuals recall specific past actions, thoughts and traits. Finally, the participant pool represented a narrow age group, (27-43), and included only Australian residents. Therefore, the findings of this study cannot be generalized to other age groups or countries.
Gerstein, D., Murphy, S., Toce, M., Hoffmann, J., Palmer, A., Johnson, R., Larison, C., Chuchro, L., Bard, A., Engelman, L., Hill, M. A., Buie, T., Volberg, R., Harwood, H., Tucker, A., Christiansen, E., Cummings, W., & Sinclair, S. (1999).Gambling Impact and Behavior Study: Report to the National Gambling Impact Study Commission. National Opinion Research Center.
Slutske, W., Davis, C., Lynskey, M., Heath, A., & Martin, N. (2022). An epidemiologic, longitudinal, and discordant-twin study of the association between gambling disorder and suicidal behaviors.Clinical Psychological Science, 1–19. https://doi.org/10.1177/21677026211062599