One out of every 30 children in the U.S. experienced homelessness last year, that makes nearly 2.5 million children who, in 2013, lived in shelters, on the streets, in cars or doubled up with other families in tight quarters, often moving from one temporary solution to another, according to “America’s Youngest Outcasts,” a report published this week by the National Center on Family Homelessness at the American Institutes for Research.

The report which draws on data from the U.S. Department of Education (DOE) as well as the Census Bureau, found that children are homeless in every county and state across the country. The report also notes that progress has been made in reducing homelessness among veterans and chronically homeless individuals due to concerted efforts by the federal government, but no special attention has been directed toward homeless children and their numbers have increased.

Major causes of child homelessness in the U.S. include: (1) the nation’s high poverty rate; (2) a lack of affordable housing; (3) the continuing impacts of the Great Recession; (4) racial disparities; (5) the challenges of single parenting; and (6) the ways in which traumatic experiences, especially domestic violence, precede and prolong homelessness for families.

Research shows that homeless children are hungry and sick more than children who are housed. The impact of homelessness on children, especially young children, may lead to changes in brain architecture that interfere with leading, emotional self-regulation, cognitive skills, and social relationships. Up to 25% of homeless pre-school children have mental health problems requiring clinical evaluation; this increases to 40% among homeless school age children. Many homeless children struggle in school, missing days and repeating grades until they drop out entirely.

According to the report, effective solutions must combine safe, affordable housing with essential supportive services. All family members must be comprehensively assessed prior to being re-housed to understand what services they need to remain residentially stable. Parents need income, which requires education, job training, transportation, and childcare. Parents may also need mental health and parenting supports to address untreated trauma and depression. Further research is necessary to understand what mix of housing and supports is most effective for which children and families.