Page 32 - Age of onset of disruptive behavior of residentially treated adolescents -Sjoukje de Boer

were admitted to De Fjord between 2001 and 2008. The average age at admission was 17.3 year (SD = 1.13 year; range 15-19 year). They were referred to the orthopsychiatric residential treatment facility by child and adolescent psychiatric institutions, youth care or judicial institutions. About a third was judicially imposed. The patients had an average 2.6 clinical diagnoses (axis I; range 1-5, SD = 1.24). Patients were diagnosed with conduct disorders, oppositional defiant disorder, schizophrenia and related disorders, mood disorders, pervasive developmental disorders and Attention Deficit Hyperactivity Disorder (APA, 2000). Although the level of intelligence (mostly measured at the institutions that requested the admission) of the sample was about average, compared to the general population the educational attainment was relatively low.
The control sample
The control group was selected from the general population and was matched to the inpatient sample based on gender and year of birth (between 1983 and 1992). Only respondents with no reported history of behavioral or psychiatric disorders were selected. It was attempted to trace 55 files, of those 7 (13%) could not be traced and of 7 files (13%) the information about the examination in the second grade was missing. The control group used in present study consisted of 25 males and 16 females.
Procedure
After a verbal description of the study to the subjects, written informed consent was obtained to gather information from their YHC files. Respondents of the patient group were informed that they could refuse cooperation without any consequence for their treatment. The YHC files, in which all information was recorded, were usually stored at the Municipal Public Health Service (MPHS) of the district where the child resided at the age of twelve. Every MPHS used the same file format, with standard (sub)headings to register notes (e.g., length, weight, illnesses, speech, hearing, temper tantrums). Of both samples, the YHC files were requested at the designated MPHS. The tracked files were viewed by the researchers at the office of the MPHS, and screened on remarks on behavior problems. Because many of the obtained files were incomplete on a later age, it was decided to focus the study on the
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