Impulsivity and its different facets have been studied for decades as some of the main personality traits linked to psychopathology. However, in recent years, research has emphasized compulsivity as a more proximal risk factor for certain disorders, leading to different theorizations on the relation between impulsivity facets and compulsivity. Building on a model proposed by Nigg (2017), this study identified the factor structure of Compulsivity and Impulsivity facets (Immediate Reward Preference, Cue-Triggered Impulsive Response, and Planful Risk-Taking) and explored their prospective associations with depressive symptoms, alcohol, and cannabis-related problems. A total of 729 emerging adults were measured at two waves of data collection, using the Impulsive-Compulsive Behaviours Checklist, UPPS-P Impulsive Behavior Scale, Sensitivity to Punishment and Sensitivity to Reward Questionnaire, Delay Discounting Task, and questionnaires designed to measure substance-related problems and depressive symptomatology. Confirmatory factor analysis revealed a four-factor orthogonal structure reflecting the lower-level facets in Nigg's model. Compulsivity predicted increased depressive symptoms, whereas CTIR predicted cannabis-related problems. Robustness analyses showed substantial but not complete consistency in findings, pointing to variations in associations depending on specific measures used to assess each construct. This study contributes to understanding the complex interplay of impulsivity and compulsivity and their relevance as vulnerability factors for different mental health conditions.