: Studies showed that affective temperaments and attachment are associated with depressive symptoms, and that they bi-directionally influence each-other. The aim of this study is to explore mechanisms underlying the relationship between the affective temperaments (i.e., depressive, cyclothymic, irritable, hyperthymic and anxious), interview-based attachment, and depressive symptoms.

: A sample of 61 adolescents and young adults outpatients were asked to complete the Temperament Evaluation of Memphis, Pisa, and San Diego Autoquestionnaire (TEMPS-A) and the Hamilton Rating Scale for Depression (HAM-D). Attachment was assessed through the Adult Attachment Interview (AAI) and employing a dimensional approach to obtain continuous measures. Mediation models were performed with the affective temperaments as predictor, depressive symptoms as the criterion variable, and attachment dimensions as mediators.

: Findings showed significant direct effects between all the affective temperaments and depressive symptoms. Only the cyclothymic (β = 0.22; SE = 0.1; 95% IC = 0.05, 0.42) and irritable (β = 0.21; SE = 0.09; 95% IC = 0.04, 0.4) temperaments showed an indirect effect on depressive symptoms through secure-insecure attachment. Dismissing attachment did not predict either the affective temperaments nor depressive symptoms. Preoccupied attachment significantly predicts depressive symptoms and, when controlling for it, the hyperthymic temperament no longer directly associates with depressive symptoms.

: The cross-sectional study design limit conclusion about causation and directionality.

: Secure attachment could be a protective factor for depressive symptoms for individuals with a cyclothymic or irritable temperament. Differently, the hyperthymic temperament loses its protective role toward depressive symptoms when accounting for preoccupied attachment.