Depression often requires long-term treatment.
Yet many patients quit medication as soon as they feel better, prompting a relapse. The FDA didn't require Lilly to prove weekly Prozac is equivalent to the daily version, just that it works compared with a placebo or dummy pill. Indeed, the FDA warned doctors to switch patients back to daily pills if they appear to decline on Prozac Weekly. Lilly studied 500 patients whose initial depression was controlled by daily Prozac. Some continued taking daily pills, others got weekly pills and others a placebo.