Implications of gambling problems for family and interpersonal adjustment: results from the Quinte Longitudinal Study

AIMS: To evaluate (1) whether gambling problems predict overall trajectories of change in family or interpersonal adjustment and (2) whether annual measures of gambling problems predict time‐specific decreases in family or interpersonal adjustment, concurrently and prospectively. DESIGN: The Quinte Longitudinal Study (QLS) involved random‐digit dialling of telephone numbers around the city of Belleville, Canada to recruit ‘general population’ and ‘at‐risk’ groups (the latter oversampling people likely to develop problems). Five waves of assessment were conducted (2006–10). Latent Trajectory Modelling (LTM) estimated overall trajectories of family and interpersonal adjustment, which were predicted by gambling problems, and also estimated how time‐specific problems predicted deviations from these trajectories. SETTING: Southeast Ontario, Canada. PARTICIPANTS: Community sample of Canadian adults (n = 4121). MEASUREMENTS: The Problem Gambling Severity Index (PGSI) defined at‐risk gambling (ARG: PGSI 1–2) and moderate‐risk/problem gambling (MR/PG: PGSI 3+). Outcomes included: (1) family functioning, assessed using a seven‐point rating of overall functioning; (2) social support, assessed using items from the Non‐support subscale of the Personality Assessment Inventory; and (3) relationship satisfaction, measured by the Kansas Marital Satisfaction Scale. FINDINGS: Baseline measures of ARG and MR/PG did not predict rates of change in trajectories of family or interpersonal adjustment. Rather, the annual measures of MR/PG predicted time‐specific decreases in family functioning (estimate: −0.11, P < 0.01), social support (estimate: −0.28, P < 0.01) and relationship satisfaction (estimate: −0.53, P < 0.01). ARG predicted concurrent levels of family functioning (estimate: −0.07, P < 0.01). There were time‐lagged effects of MR/PG on subsequent levels of family functioning (estimate: −0.12, P < 0.01) and social support (estimate: −0.24, P < 0.01). CONCLUSIONS: In a longitudinal study of Canadian adults, moderate‐risk/problem gambling did not predict overall trajectories of family or interpersonal adjustment. Rather, the annual measures of moderate‐risk/problem gambling predicted time‐specific and concurrent decreases in all outcomes, and lower family functioning and social support across adjacent waves.