The aim of the study was to investigate the potential association between gambling disorder and symptoms of sleep problems including insomnia and hypersomnolence. Gambling disorder is a behavioural addiction featuring persistent, recurrent gambling resulting in distress and impairment of function. Lifetime prevalence of gambling disorder is estimated at 0.6–0.9%, though high quality data in the UK are lacking. Psychiatric comorbidity is common; as are physical health problems such as hypertension. The association between sleep problems and other addictions such as alcohol misuse disorder, smoking and substance misuse has been established; however, research into gambling disorder and sleep problems is limited. It was hypothesised that, compared to controls, individuals with gambling disorder would have significantly greater disturbance of sleep, as indicated by increased scores in: 1) specific sleep items on the Hamilton Anxiety Rating Scale (HAMA) and Hamilton Rating Scale for Depression (HAMD), 2) total score on the HAMA and HAMD and 3) the Epworth Sleepiness Scale (ESS).

A secondary analysis of a subset of previously published data by Grant and Chamberlain (2018) on gambling and impulsivity. A total of 152 non-treatment seeking adults, aged 18–29 years, who had gambled at least five times in the past year were recruited. Individuals were stratified into three groups: controls, those at risk of gambling disorder, and those with gambling disorder, as per DSM-5 criteria. One-way ANOVAs with post-hoc tests were conducted. These were used to show whether the three groups differed significantly in their scores in the sleep items and total scores of the HAMA and HAMD, and the ESS.

The HAMD scale demonstrated a significant increase in all patterns of insomnia for members of the disorder group, when compared to controls. The increase was particularly marked for middle and late insomnia. The HAMA item score demonstrated significantly worse sleep quality in the disorder group, compared to at risk and control groups. Total scores on the HAMA and HAMD scales were also significantly higher in the disorder group, reaching the thresholds for clinical significance for anxiety and depression. ESS scores were not significantly different between groups.

Global disruptions in sleep, as well late- and middle-insomnia, were found to be significantly higher in gambling disorder than controls. Symptoms of anxiety and depression were also significantly higher in the gambling disorder group. Further research could have implications for the identification and treatment of sleep disorders and psychiatric comorbidities in gambling disorder.