This study evaluates the role of familial support and dysfunctional attitudes in depression, delinquency and the concomitance of these disorders in an adolescent population from a middle-class community in the Trois-Rivieres area. The Beck Depression Inventory and the Mesure d'adaptation sociale et personnelle pour adolescents quebecois-MASPAQ (Measure of social and personal adaptation in Quebec adolescents) were used respectively to evaluate depression and delinquency. The Mesure de la perception du soutien familial (Measure of perceived social support-family) and Echelle des attitudes dysfonctionnelles (Dysfunctional attitude scale) served to evaluate the familial and cognitive variables of the study. The findings confirm that a higher incidence of disorders concerning depression and delinquency in adolescents is associated with a lower level of familial support. Moreover, whereas dysfunctional attitudes concerning dependence and achievement are related to the presence of internal disorders such as depression, dysfunctional attitudes concerning self-control are linked to external problems such as delinquency. Findings of the test on the mediating role of dysfunctional attitudes in the relationship between familial support on the one hand and depression and delinquency on the other, do not support the presence of such a role. (Contains 3 tables.)