This paper examines the conceptual and empirical connections between competence and psychopathology, two historically rich traditions for the study of adaptation in development, and what might be gained from their integration. Historical roots of these two traditions are reviewed, then overlaps in their definition are considered, with a focus on the ways in which judgments about competence enter into the nosology of mental disorders. DSM-IV is analyzed from the perspective of competence, and the debate about "harmful dysfunction" in defining mental disorder is discussed in relation to competence. Different models explaining the empirical associations of competence and psychopathology are delineated, and illustrative empirical evidence is provided. Potential explanations include confounded concepts and methods, symptoms undermining the effectiveness of adaptation in the environment, failures in age-salient developmental tasks leading to emotional and behavioral problems, transactional influences, shared vulnerability or risk factors producing both kinds of difficulties, and more complex models. The potential benefits of integrating competence and psychopathology as two major approaches to adaptation are discussed in regard to theory, classification of mental disorder, research, and intervention.