Background/Aims To measure the association between problem gambling severity and nineteen different gambling activities among emerging adults (aged 16-26).

DESIGN An online non-probability longitudinal survey collecting data in two waves: wave 1, July/August 2019; wave 2, July/September 2020.

SETTING Great Britain PARTICIPANTS: 2080 emerging adults participating in both waves.

MEASUREMENTS Problem gambling scores were collected using the Problem Gambling Severity Index (PGSI). Binary variables recorded past year participation in nineteen different gambling forms, ranging from lotteries to online casino and gambling-like practices within digital games (e.g., loot box purchase, skin betting). Controls included socio-demographic/economic characteristics, the Eysenck Impulsivity Scale and the number of gambling activities undertaken.

FINDINGS Zero inflated negative binomial model lacked evidence of an effect between past year participation in any individual activities and subsequent PGSI scores. However, negative binomial random effects models for current gamblers (n=497) showed that skin betting (Incidence-Rate Ratio [IRR] 2.32; 95% confidence interval [CI]: 1.69-3.19), Fixed Odd Betting Terminals (IRR: 2.21, 95% CI: 1.61-3.05), slot/fruit machines (IRR: 1.43, 95% CI: 1.07-1.91), online betting on horse/dog races (IRR: 1.53, 95% CI: 1.17-2.00) and online betting on non-sports events (IRR: 1.44, 95% CI: 1.11-1.89) were associated with increased PGSI scores. Online casino gambling had a significant interaction by wave: the impact of online casino betting in wave 2 on PGSI scores increased by a factor of 1.61.

CONCLUSIONS Past year participation of emerging adults (aged 16-26) in certain forms of gambling does not appear to be associated with future Problem Gambling Severity Index (PGSI) scores. Among emerging adults who are current gamblers, past year participation in certain land-based (e.g. electronic gambling machines) and online forms (e.g. skin betting) of gambling appears to be strongly associated with elevated PGSI scores.