Problematic alcohol use (PAU) presents a major burden on health worldwide. Sampson and Laub’s Age-Graded Theory of Informal Social Control provides a unique lens through which to investigate desistance from PAU. This study explored the potential of relationship adjustment to act as a turning point, promoting desistance from PAU across the lifespan. Seventy-three participants (58 females, 15 males) who had previously experienced a period of PAU responded to an anonymous online survey. Contrary to the hypothesis, results showed that relationship adjustment did not act as a turning point predicting desistance from PAU across the lifespan in this sample. However, further analyses revealed that relationship adjustment did predict desistance for those aged 25 years and under. The findings provide partial support for the use of Sampson and Laub’s theory in the alcohol use literature, and highlight the importance of relationship adjustment in the drinking behaviors of youth. Replication and further research are needed. Implications for therapeutic practices, health promotion, and theoretical frameworks are discussed.