No study, American as well as Canadian, has examined the dynamics of change in compulsive, pathological or excessive gambler trajectories. This seeks to improve knowledge about excessive gamblers by analyzing within and between individual changes in 100 excessive gambler trajectories. Participants were recruited in therapeutic resources surrounding the city of Montreal. Monthly variations of monetary bets are analyzed, with special attention given to episodes of abstinence. The use of hierarchical linear models (HLM) allows to consider simultaneously contextual variables (the effect of conventional and deviant life circumstances), and personal characteristics (impulsiveness, gender, etc). Results show that life circumstances have an impact on the intensity of gambling and episodes of abstinence. More specifically, they highlight the importance of deviant life circumstances (criminal earnings, loan shark, alcohol and drug consumption) to understand major changes in gambling habits.