Historically, there have always been some patients who report that any treatment for depression—including bloodletting—has worked for them, but science demands that for a treatment to be deemed truly effective, it must work better than a placebo or the passage of time without any treatment. This is especially important for antidepressant drugs—including Prozac, Zoloft, and other selective serotonin reuptake inhibitors (SSRIs), as well as Effexor, Cymbalta, and other serotonin and norepinephrine reuptake inhibitors (SNRIs)—because all of these drugs have uncontroversial troubling side effects.