"There's a lot of exciting things going on, " says Kleber.

FORBES: Reinventing Rehab

Some schools, like Columbia, have raised the time spent to more like 20 hours, but the inevitable "fourth-year amnesia" sets in, Kleber says, as students focus on their residencies.

FORBES: Reinventing Rehab

Criolo, born Kleber Gomes, draws on the grit and poverty of his childhood as the son of a metalworker and a teacher in the Jardim das Imbuias favela, or shantytown.

WSJ: Brazilian Rapper Criolo: From Favela to Summerfest

"I want as many arrows in my quiver as possible, " says Herbert Kleber, director of the division on substance abuse at Columbia University and a former deputy drug czar under President Clinton.

FORBES: Reinventing Rehab