At least half of first depressive episode appear before adulthood. A negative cognitive bias is present among individuals who suffer from major depression. This bias is also reported among individuals at high risk of major depression (e.g. child of depressed mother). When present, cognitive vulnerability may predispose to major depression. No study to date aimed to evaluate the cognitive vulnerability of siblings of depressed individuals.

To review the principles behind cognitive vulnerability. To assess cognitive vulnerability in depressed adolescents, in healthy siblings and in a control group.

Eighty adolescents (27 adolescents treated for depression, 24 healthy siblings and 29 controls), aged between 12 and 20 years old, were recruited and assessed using validated measures of bio-psycho-social vulnerabilities. All diagnoses were confirmed using a K-SADS interview. Cortisol level samples were obtained through morning saliva. Cognitive vulnerability was assessed using self-report questionnaires (CES-D, LEIDS-R, EPQ) as well as computer-based tasks (Ekman's tasks of facial recognition and the movie for assessment of social cognition [MASC]). We translated the MASC from German to French. The parents of the adolescents also filled the LEIDSR and the CESD.

The LEIDS-R presented a significant increase in certain subscales (hopelessness, aggression and rumination) compared to the healthy siblings and the controls. Interestingly, there was also a correlation between the LEIDS R results of the parents and of the depressed adolescent (r = 0.43, P = 0.04).

The LEIDSR appears to be the most sensitive task to detect cognitive vulnerability. A relation between the parent response and the depressed adolescent response could be found.

The authors have not supplied their declaration of competing interest.