Innovative methods needed to understand links between gambling and self-harm

Associations between problem gambling and different forms of self-harm—including non-suicidal self-injury and suicidal ideation and attempts—have been documented in the literature.^{1, 2} However, the temporal direction and causal nature of these correlations are largely unresolved. Only a few studies have examined the longitudinal and temporal relationship between problem gambling and self-harm, partly due to difficulties reaching the population of interest.² Moreover, these studies have rarely focused on how changes in the levels of these constructs over time might affect each other. In The Lancet Public Health, Heather Wardle and colleagues³ contributed substantially to existing knowledge by showing that increased problem gambling is associated with subsequent suicide attempts.