Le retentissement des troubles dépressifs du sujet jeune en termes d'adaptation psychosociale, leur évolution possible vers une maladie dépressive récurrente et leur comorbidité psychiatrique élevée, soulignent l'importance d'une réflexion à propos de leur prévention chez des enfants et adolescents « à risque ». Des facteurs de vulnérabilité familiaux et individuels ont été identifiés. Les premiers impliquent l'hérédité mais aussi l'environnement et les interactions parents-enfants. La vulnérabilité individuelle aux troubles dépressifs fait appel aux notions de schémas cognitifs, d'impuissance apprise, d'attribution négative, d'estime de soi, de compétence sociale, et au concept de tempérament qui tient une place importante dans l'approche développementale de la psychopathologie. Pris isolément, les facteurs de vulnérabilité dépressive ont une valeur prédictive variable vis-à-vis de la survenue d'un trouble de l'humeur. C'est l'existence de plusieurs facteurs de vulnérabilité, surtout si ceux-ci s'associent à un contexte environnemental défavorable, qui permet d'identifier des enfants ou adolescents « à risque » pour les troubles de l'humeur, susceptibles de bénéficier d'interventions ciblées de prévention. Des programmes de prévention ont été développés: les uns à base cognitivo-comportementale, destinés aux enfants et adolescents ayant une symptomatologie dépressive subclinique, les autres de type guidance éducative, pour les familles dont l'un des parents est atteint d'un trouble de l'humeur. Les perspectives d'avenir offertes par une meilleure connaissance des facteurs de vulnérabilité dépressive sont ainsi discutées en termes d'applications potentielles.

Depression in children and adolescents is associated with poor psychosocial functioning, high psychiatric comorbidity, risk of recurrent episodes or onset of bipolar disorder. These findings emphasize the importance of early identification of children and adolescents having elevated risk for future depression and further development, evaluation and greater availability of prevention strategies. Our review aims an update about depressive vulnerability in children and adolescents in the perspective of better identification of at-risk populations and targeting of prevention programs. Psychopathology, in particular anxiety and disruptive disorders are well identified risk-factors for later depression. Subclinical depressive symptomatology, also termed “demoralization”, also identifies high-risk populations, likely to become incident cases of depression. It is still unclear whether this condition is prodromal depression, a specific clinical entity or the expression of biological and/or cognitive vulnerability. Familial risk for depressive disorders involves both genetic and psychosocial factors. Marital discord, poor communication and dysfunctional parenting practices are often present in families with affective disorders and can be implicated in increased depressive vulnerability in the offspring. Research on individual vulnerability in children and adolescents has focused on temperamental and cognitive characteristics. Temperament traits describe individual differences in reactivity and behavior. High emotionality, defined as the tendency to become upset easily and intensely has been associated with an increased risk for subsequent major depression. However, as the majority of high scorers will not become depressive cases, emotionality should not be the only criterion for selection of at-risk populations. Cognitive style including poor self esteem, low social competence and negative attributions are also associated with increased likelihood of depressive symptoms, but their predictive value for the onset of clinical depressive episodes needs further investigation. Familial and individual vulnerability is likely to heighten the depressogenic impact of life events and psycho-social adversity. Prevention interventions have been developed in the United States for children and adolescents at-risk for depression. In France, clinicians witness growing demands from families with affective illness concerned with risk of parent-child transmission of depressive vulnerability, prevention and early identification of symptoms. To meet this kind of emerging needs and to prevent family dysfunction, a preventive program targets offspring of depressed parents and uses clinician-based family approaches. Family and individual sessions aim a better understanding of illness experience and encourage the parents to identify and foster resilience in their children <sup>[11BEARDSLEE WR, SALT P, PORTERFIELD K et al. Comparison of preventive interventions for families with parental affective disorder. J Am Acad Child Adolesc Psychiatry 1993 ; 32 : 254-63.

Cliquez ici pour aller à la section Références]</sup>. Another type of preventive intervention focuses on children and adolescents with subclinical depressive symptoms, eventually associated with behavioral problems ou high level of parental conflict, recruited in school settings <sup>[17CLARKE GN, HAWKINS W, MURPHY M et al. Targeted prevention of unipolar depressive disorder in at-risk sample of high school adolescents : a randomized trial of a group cognitive intervention. J Am Acad Child Adolesc Psychiatry 1995 ; 34 : 312-21.

Cliquez ici pour aller à la section Références] [28JAYCOX LH, REIVICH KJ, GILLHAM J et al. Prevention of depressive symptoms in school children. Behav Res Ther 1994 ; 32 : 801-16.

Cliquez ici pour aller à la section Références]</sup>. These school-based interventions combine cognitive and social problem-solving techniques. Both familial and school-based preventive interventions have proven applicable and promising in high-risk children and adolescents. Perspectives are more systematic identification of risk groups, including youngsters with past or current non affective symptoms who might benefit from depression prevention, long-term evaluation and cross-cultural applications of prevention programs.