Children in foster care have an increased risk of exposure to adverse experiences during childhood and across the lifespan. In current studies of interventions children in foster care are often excluded, or they are too few to be included in statistical analyses of outcomes. As a consequence, knowledge on feasibility of treatment methods for some of the most exposed and maltreated children in society is sparse.

Child-Parent Psychotherapy (CPP) is an intervention for children 0-6 years who have been exposed to adverse and traumatic events. CPP is currently being implemented in Sweden. The aim of this study is to investigate the feasibility of CPP for children in foster care.

Aim. The aim of the current study is to investigate the feasibility of CPP for young children who have an increased risk of exposure to adverse and traumatic experiences with negative effects on their health and development. Feasibility will be conceptualized as acceptance of the method by therapists, caregivers, and children; practical applications of the method; any need for modifications; and observed outcomes.

Research questions The main research question is: Is CPP feasible for children in foster care? Additional research questions are: 1) How do children in foster care experience participating in CPP? 2) How do foster parents experience participating in CPP? 3) How do clinicians experience using CPP with children in foster care and their caregivers? 4) What outcomes can be observed in treatment with children in foster care in terms of increased psychological health in children and foster parents; decrease in symptoms of post-traumatic stress in children and foster parents; and foster parents' experiences of their caregiving capacity and relationship with the child.

Method Design. The project has a naturalistic mixed-methods study design. Qualitative and quantitative research methods will be used to collect and analyze data. Qualitative data concerning childrens', caregivers', and clinicians' experiences of the treatment method as well as quantitative data concerning practical applications of the method, any modifications made, and reported levels of symptoms will be studied.

Participants. Nine agencies in different regions of Sweden offering CPP as part of their regular services have accepted to participate in the study. Participants are consecutively recruited at the participating agencies. Inclusion will be terminated when 20 children have been included (whereof at least 12 children aged 3-6 years).

Procedure. At treatment start caregivers and custodians (this can include foster parents, social services, and biological parents) will be informed about the study and asked for consent to participate. Because of their low age children aged 3-6 will be informed and asked for consent to participate in connection to the interviews. Quantitative data will be collected by self-report instruments completed by the foster parents before treatment and after 20 sessions or at termination, if treatment if terminated earlier. Participation, fidelity, and modifications are registered by clinicians continuously. Foster parents and clinicians will be asked to schedule interviews by one of the researchers in the project after 20 sessions or at termination, if treatment if terminated earlier.

Background information. Demographical and background data will be collected using a form designed for this purpose, before treatment and after 20 sessions or at termination, if treatment is terminated earlier.

Instrument. Qualitative interviews focusing acceptance and experiences of the method will be conducted with children, foster parents, and clinicians. The interviews will be conducted by child psychologists experienced in clinical treatment as well as in research with families with young children in in difficult life situations. The interviews will be recorded and transcribed verbatim. Clinicians will register participation, fidelity, and any modifications after each treatment session in a log-book. Quantitative data on outcome concerning exposure, symptoms of post-traumatic stress, psychological health, and caregiving experiences will be collected by self-report instruments completed by foster parents before treatment and after 20 sessions or at termination, if treatment is terminated earlier.

Analyses. The interviews will be analyzed by thematic analysis or interpretative phenomenological analysis, according to the applicability in relation to the research questions and data collected. Descriptive statistical methods will be used to describe exposure, symptoms pre- and post-treatment, and treatment modifications made. Non-parametric statistical methods will be used to analyze and describe indications concerning outcome.

Inclusion Criteria:

• Age 0-6 years
• being offered Child-Parent Psychotherapy as part of their regular treatment

Exclusion Criteria:

• Families in need of translator for interviews.

Children in foster care offered Child-Parent Psychotherapy at any of the nine participating agencies.