**Abstract** ------------ **Aims:** To test whether patterns of impulsive decision-making (1) differ between individuals with DSM-5 substance use disorders (SUD) or non-substance-related addictive disorders (ND) and healthy controls, and (2) predict the course of SUD and ND severity. **Methods:** In a prospective-longitudinal community study, 338 individuals between age 19 and 27 were included in one of three groups: SUD (n=100), ND (n=118), or healthy controls (n=120). After one year, we assessed 312 participants again (92%). We analyzed group differences in four impulsive decision making facets applying Bayesian linear regression with the priors: delay discounting (mean= 0.37, variance= 0.02), risk-seeking for gains and for losses (each -0.16, 0.02), and loss aversion (-0.44, 0.02). We analyzed predictive associations between decision-making and SUD/ ND severity with the Bayesian prior: mean= 0.25, variance= 0.016. **Results:** Compared to controls, the SUD group displayed steeper delay discounting and lower risk-seeking for losses and the ND group displayed lower risk-seeking for losses (posterior probabilities >98%). SUD symptom change after one year was predicted by steeper delay discounting and lower loss aversion; ND symptom change was predicted by lower risk-seeking for losses and lower loss aversion (posterior probabilities >98%). We found low evidence for predictive relation between decision-making and the quantity-frequency of addictive behaviors. **Conclusions:** Impulsive decision-making characterizes SUD and ND and predicts the course of SUD and ND symptoms but not the engagement in addictive behaviors. Strength of evidence differed between different facets of impulsive decision-making and was mostly weaker than a-priori expected.