• Utviklingspsykologi (Developmental psychology)

• Psykososiale vansker blant barn og unge (Psychosocial difficulties among children and youth)

• Sosial kompetanse (Social Competence)

• Evaluering av intervensjoner og forebyggende tiltak (Intervention and prevention research

• Implementering (Implementation)

- Evaluering av MATCH–ADTC: Modulbasert behandling av barn med angst, atferdsproblemer, traumer og depresjon.

- KOBA: Kunnskapsoverføring i barnevernet: Bedre skoleprestasjoner for barn i risiko.

Barn som pårørende – en multisenterstudie.

Barne-, ungdoms- og familiedirektoratets ekspertgruppe for utvikling av faglige anbefalinger om «Trygghet og sikkerhet i barneverninstitusjoner» (2015–2016).

Engell, T., Løvstad, A. M., Kirkøen, B., Ogden, T., & Hagen, K. A. (2021). Exploring how intervention characteristics affect implementability: A mixed methods case study of common elements-based academic support in child welfare services. Children and Youth Services Review. Volume 129, available online 22 July 2021. https://doi.org/10.1016/j.childyouth.2021.106180

Aase, H., Lønnum, K., Sørlie, M.-A., Hagen K.A., Gustavson K. & Utgarden, I.-H. "Barn, unge og kriminalitet. Hvordan forhindre at barn og unge kommer inn i eller fortsetter med en kriminell løpebane? Oppsummering og vurdering av virksomme tiltak, behandling og organisering". Rapport 2020. Oslo: Folkehelseinstituttet, 2020.

Engell, T., Kirkøen, B., Aarons, G. A., Hagen, K. A. (2020). Individual level predictors of implementation climate in child welfare services. Children and Youth Services Review. https://doi.org/10.1016/j.childyouth.2020.105509.

Engell, T., Kirkøen, B., Hammerstrøm, K. T., Kornør, H., Ludvigsen, K. H. og Hagen, K. A. (2020). Common Elements of Practice, Process and Implementation in Out-of-School-Time Academic Interventions for At-risk Children: a Systematic Review. Prevention Science. doi.org/10.1007/s11121-020-01091-w.

Apeland, A. & Hagen, K. A. (2019) Diagnoser på godt og vondt. KONTEKSTonline, 3. ISSN 2535-4825.

Hagen, K. A., Backer-Grøndahl, A., Idsøe, T., Olseth, A. R., & Frønes, I. (2019) Tiltak mot utenforskap finnes, men tas ikke i bruk. Aftenposten.

Hagen, K. A, Olseth, A. R., Laland, H., Rognstad, K., Apeland, A., Askeland, E., Taraldsen, K., Christensen, B., Kjøbli, J., Ugueto, A. M., Bearman, S. K., & Weisz, J. (2019). Evaluating Modular Approach to Therapy for Children with Anxiety, Depression, Trauma and Conduct Problems (MATCH-ADCT) in Norwegian child and adolescent outpatient clinics: Study protocol for a randomized controlled trial. Trials. doi: 10.1186/s13063-018-3074-9. (Open access.)

Hukkelberg, S., Amlund Hagen, K. & Askeland Sandbu, R. (2019). MATCH-ADTC – transdiagnostisk behandling for barn og unge i psykisk helsevern. BestPractice.

Kirkøen, B., Engell, T., Andersen, A., & Hagen, K. A. (2019). Barn i barnevernet og skolefaglig utvikling. Norges barnevern.https://doi.org/10.18261/ISSN.1891-1838-2019-04-04.

Hilsen, M., Kallander, E., Ruud, T., & Hagen, K. A. (2016). Health related quality of life in a Norwegian sample of children and adolescents living in families with parental physical or mental illness or substance abuse. Manuscript under review.

Hagen, K. A., & Ogden, T. (2016). Predictors of changes in child behavior following parent management training: Child, Context, and Therapy Factors. International Journal of Psychology, doi: 10.1002/ijop.12365. [E-pub ahead of print].

Stavnes, K., Hagen, K. A., & Ruud, T. (2016). Lov i praksis: Helsevesenets oppfølging av pasienters barn. Rus og samfunn, 9, 33–37.

Ogden, T., & Hagen, K. A. (2014). Adolescent mental health: prevention and intervention. London: Routledge.

Gere, M. K., Hagen, K. A., Villabø, M. A., Arnberg, K., Neumer, S-P., & Torgersen, S. (2013). Father's mental health as a protective factor in the relationship between maternal and child depressive symptoms. Depression and Anxiety, 30, 31–38.

Ogden, T., & Hagen, K. A. (2012). System-oriented Interventions in Europe. I: Persisters and desisters in crime from adolescence into adulthood: explanation, prevention and punishment. Ashgate 2012. ISBN 978-1-4094-3192-3. s. 413–429.

Hagen, K. A., Ogden, T., & Bjørnebekk, G. (2011). Treatment Outcomes and Mediators of Parent Management Training: A One-Year Follow-Up of Children with Conduct Problems. Journal of clinical child and adolescent psychology, 40, 165–178.

Hagen, K. A., & Christensen, B. (2010). Atferdsproblemer hos ungdom: Utvikling, risikofaktorer og behandling. I: Sårbare unge: Nye perspektiver og tilnærminger. Oslo: Gyldendal Akademisk.  

Ogden, T., Hagen, K. A., Askeland, E., Christensen, B. (2010). Implementing and Evaluating Evidence-Based Treatments of Conduct Problems in Children and Youth in Norway. Intervention: International Journal of Mental Health, Psychosocial Work and Counselling in Areas of Armed Conflict, 8, 207–222.

Kjøbli, J., & Hagen, K. A. (2009). A Mediation Model of Interparental Collaboration, Parenting Practices, and Child Externalizing Behavior in a Clinical Sample. Family Relations, 58, 275–288.

Ogden, T., & Hagen, K. A. (2009). What works for whom? Gender differences in intake characteristics and treatment outcomes following Multisystemic Therapy. Journal of Adolescence, 32, 1425–1435. 

Ogden, T., Hagen, K. A., Askeland, E., & Christensen, B. (2009). Implementing and evaluating evidence-based treatments of conduct problems in children and youth in Norway. Research on social work practice, 19, 582–591.

Ogden, T., & Hagen, K. A. (2008). Treatment effectiveness of Parent Management Training in Norway: A randomized controlled trial of children with conduct problems. Journal of Consulting and Clinical Psychology, 76, 607–621.

Sørlie, M-A., & Hagen, K. A., & Ogden, T. (2008). Social Competence and Antisocial Behavior: Continuity and Distinctiveness Across Early Adolescence. Journal of Research on Adolescence, 18, 121–144.

Ogden, T., Hagen, K. A., Andersen, O. (2007). Sustainability of effectiveness of a programme of multisystemic treatment (MST) across participant groups in the second year of operation. Journal of Children's Services, 2, 4–14.

Ogden, T., Sørlie, M-A., & Hagen, K. A. (2007). Building strength through enhancing social competence in immigrant students in primary school. A pilot study. Emotional and Behavioural Difficulties, 12, 105–117.

Hagen, K. A., & Ogden, T. (2006). Evaluering av multisystemisk behandling i Norge. Tidsskriftet Norges Barnevern, 83, 3–12.

Ogden, T., & Hagen, K. A. (2006). Multisystemic Treatment of Serious Behaviour Problems in Youth: Sustainability of Effectiveness Two Years after Intake. Child and Adolescent Mental Health, 11, 142–149.

Ogden, T., & Hagen, K. A. (2006). Virker MST? Kommentar til en systematisk oversikt og meta-analyse av MST. Nordisk sosialt arbeid, 26, 222–233.

Hagen, K. A., Myers, B. J., Mackintosh, V. H. (2005). Hope, Social Support, and Behavioral Problems in At-Risk Children. American Journal of Orthopsychiatry, 75, 211–219.

Hagen, K. A. (2004). Stress, emotion regulation, and social competence in high-risk children: Testing moderator and mediator models via structural equation modeling. Virginia Commonwealth University: Dissertation Abstracts International: Section B: The Sciences and Engineering, 65(4-B), 114 s.

Hagen, K. A., & Myers, B. J. (2003). The Effect of Secrecy and Social Support on Behavioral Problems in Children of Incarcerated Women. Journal of Child and Family Studies, 12, 229–242.

Myers, B. J., Smarsh, T. M., Hagen, K. A., & Kennon, S. (1999). Children of Incarcerated Mothers. Journal of Child and Family Studies, 8, 11–25.