**5.4 Discussion**

This study was designed to determine the prevalence rates of behavioural and emotional problems for different informants among 3-6-year-old preschool children and to evaluate demographic factors which may be associated with prevalence.

In conclusion, 5 - 6 % predominantly clinically relevant internalizing problems were found. From the total of 447 children, 12 – 13 % met the criterion of the clinical range of internalizing mental health problems. Thus, an important finding across informants was higher prevalence for internalizing than externalizing problems in preschool children. Other studies in this age group have found higher rates of externalizing as opposed to internalizing problems (Bongers et al., 2003; Campbell, 2006). Therefore, this result was unexpected and might be important in understanding mental health in the preschool years. Such discrepancies may result from different assessment measures, procedures, and normative data. The use of the CBCL ASEBA preschool forms (Achenbach & Rescorla, 2000) is a particular strength of the study, as the CBCL is a well-established measure of mental health morbidity. While this advantage is important, the study was limited by the lack of representativeness. So far, no comparable studies using ASEBA preschool instruments have been published. When interpreting the results, it should be taken into account that the child mental health status was assessed by a symptom checklist questionnaire. Given a large number of subjects and multiple informants, the questionnaire approach is economical and offers useful information, but lacks the specificity and additional depth that structured psychiatric interviews might provide.

When compared with other studies of older children, many similarities are seen concerning the associations between prevalence and demographic factors. In the current study, parental education, income, and immigrant status were also significantly associated with mental health problems of preschool children. In contrast to earlier studies, we observed effects specific to internalizing problem behaviour. In this context, it is essential to underline the fundamental longitudinal results of Wadsworth and Achenbach (2005), who found more interactions of SES over time, indicating increasing socioeconomic differences for child behaviour problems. The results for odds ratios are consistent with those reported by Harland et al. (2002) for a larger range of children's age.

The results of the present study revealed that the psychopathology of preschool children was already as high as has been found in studies of school children and adolescents. An increased utilization of child mental health services by older children, who already show disturbance in preschool years, has important implications for early preschool recognition of child mental health problems and indicates the need for the prevention and development of a differentiated delivery of child mental health services for preschool children. Clinicians working in primary care, day care, or school systems need to be attentive to opportunities for early detection and intervention regarding preschoolers' emotional and behavioural problems, particularly since efficacious prevention and treatment exists for the psychopathology of young children (e.g. Weisz et al., 2005).
