In a room in East Oakland, Calif., photos of children are projected on a screen. “Who is that?” asks Briana Moore, a licensed clinical social worker in private practice and a master trainer for the East Bay Agency for Children’s Trauma Transformed program. “Bill Clinton,” responds one of the 20 employees of the East Oakland Youth Development Center (EOYDC).

Sengthong Sithounnolat, Jeris Woodson, Donald Greene, Ashley Blanco On a recent Saturday, 10 people gather around a table at the offices of Trauma Transformed in Oakland, Calif., where quotes from figures like Frederick Douglas, Nelson Mandela, and Coretta Scott King grace one wall as light streams in from a skylight above. The group is known as the Resident Warriors, which meets weekly. One participant talks of her recovery from addiction and her mother’s murder. Another mentions being...