clipped from: psychcentral.com 
Of the approximately half-million children and adolescents in foster care in the U.S., experts estimate that 42 to 60 percent of them have emotional and behavioral problems. 
About half of the sample experienced more than three placement changes during their first spell in foster care. Inpatient mental health episodes among white children increased the likelihood of placement instability for them by 75 percent, while such episodes decreased the likelihood of permanence by 24 percent among African-American children.
The study also suggested that there was limited access to and underutilization of mental health services among African-American children.
Foster-care placements come at considerable cost to taxpayers: Placement in therapeutic foster care can cost $30,000 or more annually, and placement in residential psychiatric care considerably more.