Objectives. According to Blatt's theory on personality development, adolescents with high levels of self-criticism and dependency are more vulnerable to diverse types of psychopathology. However, relatively little is known about intervening processes involved in this personality-based vulnerability. The goal of this study is to examine, on the basis of Self-Determination Theory, the explanatory role of the psychological needs for autonomy, competence, and relatedness in associations between self-criticism and dependency on the one hand and adolescents' internalizing and externalizing problems on the other hand. Method. In this cross-sectional and multi-informant study, 284 adolescents (58,5% female; mean age = 14.15; SD = .93) and their parents reported about the adolescent's internalizing and externalizing problems. Adolescents also completed measures assessing self-criticism, dependency, and psychological needs experiences. Data were analyzed using structural equation modeling. Results. Self-criticism and dependency were significantly related to higher levels of both internalizing and externalizing problems, with psychological need frustration fully mediating these associations. No evidence for a mediating role of need satisfaction was found. Conclusion. This study suggests that psychological need frustration is an important explanatory mechanism in personality-related vulnerability for adolescent psychopathology. More generally, it provides further evidence for the integration between two major theoretical approaches in the domain of adolescent development and psychopathology.