Psychosocial problems, such as social-emotional and behavioral problems, are prevalent among preschool children; in approximately 8-9 percent of preschool children, child health professionals identify psychosocial problems, such as anxious or depressed feelings and aggressive or disobedient behavior [1, 2]. Psychosocial problems in this age group can interfere with everyday functioning [[3–5]]. Research has demonstrated that problems at preschool age are associated with depressive symptoms, oppositional defiant or conduct disorder, poor peer relationships and social skills, parent- and teacher reported problems with externalizing and internalizing behavior, poor academic performance and psychiatric problems later in life [[6–9]]. A retrospective study  demonstrated that adolescents with psychosocial problems already had neurocognitive, temperament and behavioral problems at age two or three years old.
It has been recommended that psychosocial problems can be detected at a very young age and followed by appropriate management [[11–13]]. Research has shown that detection and treatment of psychosocial problems at a young age significantly reduces problems and increases competencies [14, 15]. Preventive youth health care, as part of community care or paediatrics, offers an opportunity for the early detection of psychosocial problems among preschool children. Child health professionals, such as physicians and nurses who provide preventive care, may apply early detection of psychosocial problems and if necessary adequate referral or short counselling . In the Netherlands, participation of parents with their child in the preventive youth health care is free of charge and on voluntary basis; almost 95% of the parents of preschool children make use of the youth health care service .
Despite the potential impact of psychosocial problems at preschool age and the presence of easily accessible youth health care, only a relatively small number of children with psychosocial problems receive appropriate care [2, 5]. One study showed that only 29% of the children with severe problems, based on a Child Behavior Checklist (CBCL) total problem score in the clinical range, were identified by child health professionals . And, in another study, only 13% of the children who scored in the clinical range of the CBCL total problem score were referred to mental health services .
In current preventive youth health care in the Netherlands, child health professionals apply a structured questionnaire about psychosocial problems that parents complete before coming to the youth health care center, which helps to structure the conversation between child health professionals and parents; there are no validated norm tables or cut-off scores that indicate when the questionnaire signals a problem .
As an alternative to this procedure, it has been recommend to evaluate the use of the Brief Infant-Toddler Social and Emotional Assessment (BITSEA)  for 1-3 year olds, to detect children at-risk for psychosocial problems and to act upon detection in a coherent, effective way .