1 Department of Psychology, Université du Québec à Montréal, Montreal, Canada; Research Centre, CHU Sainte-Justine, Montreal, Canada.
2 Research Centre, CHU Sainte-Justine, Montreal, Canada; Department of Psychiatry and Addictology, Université de Montreal, Montreal, Canada; Department of Psychology, Concordia University, Montreal, Canada.
3 Research Centre, CHU Sainte-Justine, Montreal, Canada; Department of Psychiatry and Addictology, Université de Montreal, Montreal, Canada; Department of Psychiatry, CHU Sainte-Justine, Montreal, Canada.
4 Department of Psychiatry, University of British Columbia, Vancouver, Canada.
5 Department of Psychology, Université de Montréal, Montreal, Canada.
6 Research Centre, CHU Sainte-Justine, Montreal, Canada; Department of Psychology, Université de Montréal, Montreal, Canada.
7 Department of Psychology, Université du Québec à Montréal, Montreal, C

Background and objectives: Depression has been associated with alterations in social functioning. Decoding and understanding others' mental states and adaptive reasoning are important for social functioning. This study examined theory of mind (ToM) and socio-moral reasoning (SMR) in adolescent girls with and without depression. Within the depression group, we examined associations between relevant clinical features (depression severity, anxiety symptoms and borderline personality traits) and ToM and SMR.

Methods: A cross-sectional study was conducted, whereby 43 adolescent girls (mean age = 16.19, SD = 1.24) meeting full or subthreshold criteria for depression and 40 adolescent girls (mean age = 15.44, SD = 1.24) with no psychiatric diagnosis were recruited. ToM was assessed using the Movie for the Assessment of Social Cognition; SMR was evaluated via the Socio-Moral Reasoning Aptitude Level task.

Results: Analyses of covariance indicated that adolescents with depression did not differ from controls in ToM abilities but showed lower socio-maturity scores on the SMR task. This difference disappeared after controlling for the number of words used to justify responses. Amongst adolescents with depression, multiple linear regression analyses revealed that higher levels of borderline personality traits were associated with lower levels of mentalization (ToM task), and more severe depressive symptoms were associated with lower socio-moral maturity stages (SMR task) LIMITATIONS: Directional associations were not studied, and the sample included only girls.

Conclusions: Findings may help to explain clinical heterogeneity in social cognitive functioning observed in individuals with depression.