PostprintThis is the accepted version of a paper published in Nordic Journal of Psychiatry. This paper has been peer-reviewed but does not include the final publisher proof-corrections or journal pagination.Citation for the original published paper (version of record):Gustafsson, B., Gustafsson, P., Proczkowska Björklund, M. (2016) The strengths and difficulties questionnaire (SDQ) for preschool children: a Swedish validation.

BackgroundThere is a high risk that young children who show early signs of mental health problems develop symptoms in the same or overlapping areas some years later. The Strengths and Difficulties Questionnaire (SDQ) is widely used to screen externalizing and internalizing problems early in life. In Sweden 80–90% of all children aged 1–5 years go to preschool and preschool is thus an appropriate context for finding early signs of mental health problems among children.MethodsThis study is part of a longitudinal project too investigate the frequency of emotional and behavioural problems for children between 1 and 5 years of age in Sweden. The SDQ including the impairment supplement questions were rated by preschool teachers too establish Swedish norms for SDQ in preschool children.ResultsThe sample involved 815 children with a mean age of 42 months (SD = 16, range 13–71 months). 195 children were followed longitudinally for three years. There were significant differences between boys and girls on all subscales except for the Emotional subscale. The prevalence of behavioural problems was similar to other that in European countries, except for Prosocial behaviour, which was rated lower, and Conduct problems, rated higher. Swedish children were estimated to have more problems in the preschool setting, scored by preschool teachers. The development of behaviour over time differed for the different subscales of SDQ.ConclusionsThe teacher version of the SDQ, for 2–4 year-olds, can be used as a screening instrument to identify early signs of emotional distress/behavioural problems in young children. Preschool teachers seem to be able to identify children with problematic behaviour with the use of SDQ at an early age. The development of behaviour over time differs for the different subscales of SDQ. The Swedish norms for SDQ are to a large extent, similar to findings from other European countries.

The main objective of this article was to study the relationship between the different areas of victimization (eg, sexual victimization) and psychological symptoms, taking into account the full range of victimization domains. The final aim was to contribute further evidence regarding the bias that studies that focus on just one area of victimization may be introduced into our psychological knowledge. The sample included 5,960 second-year high school students in Sweden with a mean age of 17.3 years (range =16–20 years, standard deviation =0.652), of which 49.6% were females and 50.4% males. The Juvenile Victimization Questionnaire and the Trauma Symptom Checklist for Children were used to assess victimization and psychological problems separately. The results show that a majority of adolescents have been victimized, females reported more total events and more sexual victimization and childhood maltreatment, and males were more often victims of conventional crime. The majority of victimization domains as well as the sheer number of events (polyvictimization [PV]) proved to be harmful to adolescent health, affecting females more than males. PV explained part of the health effect and had an impact on its own and in relation to each domain. This suggests the possibility that PV to a large degree explains trauma symptoms. In order to understand the psychological effects of trauma, clinicians and researchers should take into account the whole range of possible types of victimization.