Medicine Has a Rat Problem

Thirty years ago, antidepressant research seemed on the verge of a major breakthrough. Years of experiments with laboratory rats and mice—animals long considered “classic” models for the condition—had repeatedly shown that a new drug called rolipram could boost a molecule in the rodent brain that people with depression seemed to have lower levels of. Even guinea pigs and chipmunks seemed susceptible to the chemical’s effects. Experts hailed rolipram as a potential game changer—a treatment that might work at doses 10 to 100 times lower than conventional antidepressants, and act faster to boot.

But not long after rolipram entered clinical trials in humans, researchers received a nasty surprise. The volunteers taking rolipram Terrible bouts of nausea were leading some participants to quit taking the