Objectives: There is a need for updated population-based epidemiological
data that address mental health disorders among children and adolescents in
the child welfare system in order to develop social and mental health services.
We fill the gap in the literature by examining: 1) the prevalence of ADHD and
disruptive behavior disorders (DBDs) such as ODD or conduct disorder; and 2)
the impact of the degree of ADHD vs ADHD and co-occurring DBDs on the
likelihood for out-of-home care placements in children.
Methods: The Southwest Finland Birth Cohort (SFBC) consists of all live-born
children in the Hospital District of Southwest Finland born from January 2008
to December 2010 (N ¼ 14,946; 51.2% males). The data originated from the
following national registers: the Care Register for Health Care and the Register
of Child Welfare (maintained by the Finnish Institute for Health and
Welfare), and the Prescription Register (maintained by the Social Insurance
Institution). The follow-up ended on May 31, 2019.
Results: The cumulative prevalence of ADHD in SFBC children was 5.5%. In
addition, 0.7% of the cohort children were diagnosed with ADHD and cooccurring
DBD, or DBD only. A total of 360 children had been placed into outof-
home care during the follow-up (2.4%). Compared with the cohort children
without ADHD or DBD, the crude OR for out-of-home care in children with
ADHD was 4.6 (95% CI, 3.5-6.1; p < 0.001), and for those with ADHD and cooccurring
DBD or DBD only, the OR was 22.0 (95% CI, 14.4-33.6; p < 0.001).
Conclusions: In this total population cohort study, we discovered that ADHD
and co-occurring DBD, or DBD only, in particular, is related to the likelihood
for out-of-home care in children. Further research is needed to better understand
the extent to which different symptom dimensions (eg, irritability)
increase the risk for out-of-home care in children with ADHD in order to
inform treatment planning.