Mentalization and depressive symptoms in a clinical sample of adolescents and young adults

Background: Increasing evidence supports that mentalization deficits may have a role in the genesis of young age depression; however, few studies examined this issue in clinical populations. Methods: Outpatients aged 14–21, suffering from various psychiatric disorders, were assessed using the Mentalization Questionnaire (MZQ), the Beck Depression Inventory (BDI), and the Childhood Trauma Questionnaire (CTQ), using data from age-matched healthy students for comparison. The relationship between CTQ, MZQ, and BDI scores was examined at the cross-sectional level, including mediation analyses, and longitudinally, in a subsample who underwent a psychotherapy intervention. Results: Of 83 subjects, 33 (39.8%) had mentalization levels that were 1 standard deviation below those of comparison subjects. In the whole sample, the levels of mentalization were inversely associated with BDI (r = −.68, p <.001) and CTQ scores (r = −.30, p =.006). Moreover, MZQ scores mediated a large part of the effect of childhood trauma on depression (total effect: 10.6, 95% CI: 5.3, 15.9; direct effect: 6.5, 95% CI: 2.1, 10.8; indirect effect: 4.1, 95% CI: 1.5, 7.4). This effect was almost entirely explained by the Affect Regulation subscale. In patients re-evaluated after four sessions (n = 37), the decrease in BDI scores correlated with the increase in MZQ scores (r =.40, p =.02). Conclusions: In a juvenile clinical sample, deficits of mentalization abilities were associated with the severity of depression and explained part of the depressogenic effects of childhood trauma.