WASHINGTON – The number of grandparents who are raising their grandchildren is going up, and increasingly it's because their own children are addicted to heroin or prescription drugs, or have died from an overdose. For some, it's a challenge with little help available.

In 2005, 2.5 million children were living with grandparents who were responsible for their care. By 2015, that number had risen to 2.9 million.

Child welfare officials say drug addiction, especially to opioids, is behind much of the rise in the number of grandparents raising their grandchildren, just as it was during the crack cocaine epidemic of the 1980s and '90s. An estimated 2.4 million people were addicted to opioids at last count.

Caseworkers in many states say a growing number of children are neglected or abandoned by parents who are addicted. That has forced them to take emergency steps to handle a growing crisis in foster care — and often to turn first to grandparents for help.

"Obviously, the numbers have grown because of the current national opioid epidemic," said Maria Moissades, who heads Massachusetts' Office of the Child Advocate. "You've got grandparents who thought they were going to spend their retirement fishing and traveling. Now they're raising [as many as] five grandkids."

Federal law requires that states consider placing children with relatives in order to receive foster care and adoption assistance. And grandmothers and grandfathers often are the first — and best — choice when state and local caseworkers have to take a child out of a home and find someone else to take custody, said Angela Sausser, executive director of the Public Children Services Association of Ohio, a coalition of public child safety agencies in the state.

In some instances, caseworkers say, grandparents are also struggling with addictions. In Ohio, for instance, the opioid epidemic has grown so large that caseworkers sometimes have a hard time finding any relatives who can step up, said Kim Wilhelm, protective services administrator for Licking County Department of Job and Family Services.

For every child in foster care who has been placed with a relative, another 20 children are being raised by relatives outside the system, said Jaia Lent, deputy executive director of Generations United, a Washington, D.C.-based family research and advocacy group.

Many grandparents face a host of emotional and financial challenges in their renewed parenting role. Twenty-one percent of grandparents caring for grandchildren live below the poverty line, according to Generations United. About 39 percent are over 60 and 26 percent have a disability. And because many are not licensed in the system, they are not eligible for the same services and financial support as licensed foster parents.

"Can't y'all make it easier for grandparents? That's my request," said Dot Thibodeaux, founder of the grass-roots support group Grandparents Raising Grandchildren Information Center of Louisiana. "Most of us are on Social Security. When the family grows, the Social Security does not. You have to make do with whatever you were getting, and that's kind of hard."