摘要:Background Adolescents are a vulnerable group when it comes to the risk of developing depression. Preventing the onset of depressive episodes in this group is therefore a major public health priority. In the last decades, school-based cognitive-behavioural interventions have been a common primary prevention approach. However, evidence on what girls actually are allocated to such interventions when no researchers are involved is scarce. Objective To explore how a selective cognitive-behavioural program (Depression In Swedish Adolescents) developed to prevent depression in adolescents, was implemented in a naturalistic setting in schools in northern part of Sweden. The focus was on characteristics of participants allocated to the intervention. Design Cross-sectional baseline data on depressive symptoms, school environment and socio-economic factors were collected in 2011 by means of questionnaires in schools in a municipality in the northern part of Sweden. Intervention participants were identified in a follow-up questionnaire in 2012. Students (n=288) included in the analyses were in the ages of 14–15. Results Sixty-six girls and no boys were identified as intervention participants. They reported higher levels of depressive symptoms, lower personal relative affluence, more sexual harassment victimization and less peer support compared to female non-participants (n=222). Intervention participants were more likely to attend schools with a higher proportion of low parental education levels and a lower proportion of students graduating with a diploma. Conclusions The developers of the intervention originally intended the program to be universal or selective, but it was implemented as targeted in these schools. It is important for school administrations to adhere to program fidelity when it comes to what students it is aimed for. Implications for effectivenss trials of cognitive-behavioural interventions in the school setting is discussed.