Co-registration This review is co-registered within both the Cochrane and Campbell Collaborations. A version of this review can also be found in the Cochrane Library. Keywords Contributions Karlsen conceived of the idea and commissioned the review. All reviewers were involved in planning the review. Smedslund wrote the methods section of the protocol. Karlsen and Smedslund wrote the background. Hammerstrøm developed the search strategy, performed the original searches and the final search in November 2010. All authors were involved with screening of studies. Smedslund and Berg did the risk of bias and data extraction. Berg and Smedslund graded the results. Smedslund did the analyses and wrote the results and discussion. Support/Funding Norwegian Knowledge Centre for the Health Services, Norway Potential Conflicts of Interest None.

Co-registration This review is co-registered within both the Cochrane and CampbellCollaborations. A version of this review can also be found in the Cochrane Library. KeywordsContributions Karlsen conceived of the idea and commissioned the review. All reviewers were involved in planning the review. Smedslund wrote the methods section of the protocol. Karlsen and Smedslund wrote the background. Hammerstrøm developed the search strategy, performed the original searches and the final search in November 2010. All authors were involved with screening of studies. Smedslund and Berg did the risk of bias and data extraction. Berg and Smedslund graded Motivational interviewing for substance abuse (Review)

Co-registration This review is co-registered within both the Cochrane and CampbellCollaborations. A version of this review can also be found in the Cochrane Library. KeywordsContributions Dalsbo and Smedslund wrote the protocol. All reviewers independently screened literature, reviewed potential trials, and extracted data. Smedslund analysed the data. Smedslund wrote the text of the completed systematic review. Dalsbo coordinated and wrote the 2010 updated version. Steiro, Winsvold and Clench-Aas contributed by giving comments, assessing studies and acting as mediators if necessary. Responsibility for updating the review is jointly shared between Dalsbo and Smedslund.

Background: Early trauma-focused cognitive-behavioural therapy (TFCBT) holds promise as a preventive intervention for people at risk of developing chronic post-traumatic stress disorder (PTSD). The aim of this review was to provide an updated evaluation of the effectiveness of early TFCBT on the prevention of PTSD in high risk populations.

Co-registration This review is co-registered within both the Cochrane and Campbell Collaborations. A version of this review can also be found in the Cochrane Library. Keywords Contributions Karlsen conceived of the idea and commissioned the review. All reviewers were involved in planning the review. Smedslund wrote the methods section of the protocol. Karlsen and Smedslund wrote the background. Hammerstrøm developed the search strategy, performed the original searches and the final search in November 2010. All authors were involved with screening of studies. Smedslund and Berg did the risk of bias and data extraction. Berg and Smedslund graded the results. Smedslund did the analyses and wrote the results and discussion. Support/Funding Norwegian Knowledge Centre for the Health Services, Norway Potential Conflicts of Interest None.