['We tested the hypothesis that high novelty seeking (NS) (a trait that promotes experimentation) and sweet-liking (SL) (a phenotype that may reflect processing of hedonic stimuli) act independently and synergistically to increase the risk of having alcohol-related problems in young adults.', 'A sample of 163 young adults, ages 18 to 26, was recruited and balanced for gender and evidence for presence of alcohol problems to yield 150 evaluable participants. NS was evaluated using the Tridimensional Personality Questionnaire. Pleasurable response to sweet taste was tested to identify sweet-likers and sweet-dislikers. Alcohol use and problems were assessed by the Alcohol Use Disorders Identification Test and the Rutgers Alcohol Problem Index.', 'NS, but not SL, was positively and significantly associated with alcohol consumption and alcohol problems; however, the effect of NS on alcohol problems was significantly enhanced in the presence of the SL phenotype, thus showing a strong synergistic interaction. The combination of SL and high NS was associated with increased odds of having alcohol problems -20.64 (95% CI: -89.98, 4.74) compared to those with low NS and sweet-disliking. Other combinations did not produce such odds ratios. SL and low NS showed OR = 1.88 (95% CI 0.44, 7.99), and sweet-dislikers and high novelty seekers had OR = 4.07 (95%, CI 1.01, 16.46).'] Is sweet-liking associated with transformation of heavy drinking into alcohol-related problems in young adults with high novelty seeking?