Page 82 - Age of onset of disruptive behavior of residentially treated adolescents -Sjoukje de Boer

To describe the sample, participants were interviewed by research assistants to gather bio-demographical information. These research assistants were psychology students in the final year of their master program, who were trained and supervised by the researcher.
Participants
All 226 inpatients admitted during a 14-year period (1995-2009) were approached to participate. Two had committed suicide during treatment and were therefore excluded. The sample was comprised of 52 female and 172 male participants with a mean age of 17.7 years. Although the level of intelligence (mostly measured at the institutions that requested the admission) of the sample was approximately average, the educational attainment was relatively low. In addition to their psychiatric problems, all participants displayed severe disruptive behaviour.
Measures
Data for the study were collected with different instruments. Some of the data originated from a client interview, some of the data were collected through file review and some by self-report instruments. In order to capture the relevant behaviour characteristics as comprehensive as possible, some information (e.g., criminal offending, substance use) were obtained from interview as well as file review. This information was gathered on standardized forms used in the context of ongoing program evaluation conducted at the facility. Drug usage was queried by type and age at onset. Criminal offending was queried by type, frequency and age at onset.
Interview
Participants were interviewed on socio-demographic information (e.g., sex, age, ethnicity), academic functioning, substance usage, and criminal offending by research assistants. During the intake procedure, the participant, his parents and the referring professional (e.g., guardian or probation officer) were also interviewed by the therapist involved, in order to obtain elaborate information about relevant characteristics as complete as possible (e.g., substance use, criminal offending).
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