Officials in states hit hard by heroin use, such as Ohio, say the drug is a major reason for the increasing number of children being placed in foster care.
"What we're finding more and more is that the parents are addicted to opiates. And more often than not, it's heroin," said Timothy Dick, Assistant Director of Child Protective Services in Clermont County, Ohio.
More than half the children placed in foster care in the county this year have parents who are addicted to opiates, he said.
In Ohio, 23 percent of child welfare cases investigated in 2013 involved heroin or cocaine, compared with 19 percent three years earlier. The Public Children Services Association of Ohio found 70 percent of children less than a year old who were placed in foster care had parents who were using those drugs.
The number of children living in foster care started to increase in 2013, after years of decline, according to The Huffington Post.
In 2014, about 415,000 children in the United States were living in foster care; 15 percent were under age 2.
Nancy Young, Director of the National Center on Substance Abuse and Child Welfare, said while it is not clear how many cases involve parents who abuse drugs or alcohol, caseworkers and judges say most of them do.
In Indiana, 18,925 children were in the child welfare system as of July. Governor Mike Pence linked the high number of children in the system to drug abuse, especially heroin. He hired 113 new caseworkers this year to help handle the increase.
Substance abuse was cited in more than one-third of phone calls to Vermont's child protection hotline. The number of children in state custody rose 33 percent in one year, to 1,326.