In this interesting article about the placebo effect there are some funny things:

Two comprehensive analyses of antidepressant trials have uncovered a dramatic increase in placebo response since the 1980s. One estimated that the so-called effect size (a measure of statistical significance) in placebo groups had nearly doubled over that time.

It's not that the old meds are getting weaker, drug developers say. It's as if the placebo effect is somehow getting stronger.

The fact that an increasing number of medications are unable to beat sugar pills has thrown the industry into crisis. The stakes could hardly be higher. In today's economy, the fate of a long-established company can hang on the outcome of a handful of tests.

And:

As a psychiatrist, Potter knew that some patients really do seem to get healthier for reasons that have more to do with a doctor's empathy than with the contents of a pill.

Potter discovered, however, that geographic location alone could determine whether a drug bested placebo or crossed the futility boundary. By the late '90s, for example, the classic antianxiety drug diazepam (also known as Valium) was still beating placebo in France and Belgium. But when the drug was tested in the US, it was likely to fail. Conversely, Prozac performed better in America than it did in western Europe and South Africa.

But we also get some explanations like these:

US scientists had found that a drug called naloxone blocks the pain-relieving power of placebo treatments. The brain produces its own analgesic compounds called opioids, released under conditions of stress, and naloxone blocks the action of these natural painkillers and their synthetic analogs.

Placebo-activated opioids, for example, not only relieve pain; they also modulate heart rate and respiration. The neurotransmitter dopamine, when released by placebo treatment, helps improve motor function in Parkinson's patients. Mechanisms like these can elevate mood, sharpen cognitive ability, alleviate digestive disorders, relieve insomnia, and limit the secretion of stress-related hormones like insulin and cortisol.

It makes me believe that we can say that a placebo has an healing effect because it reduces stress. And this makes me think that maybe forgiveness is good for the health (see my blog post about it) because it reduces stress too.

In fact there was this quote in my article where "stress" appears:

people who won't forgive the wrongs committed against them tend to have negative indicators of health and well-being: more stress-related disorders, lower immune-system function, and worse rates of cardiovascular disease than the population as a whole. In effect, by failing to forgive they punish themselves.

This makes me think that we underestimate a lot the good effect that calm, and things that can bring us calm, have on us. So let's think more often about these things that can bring us calm like: seeing a beautiful landscape, seeing friends, seeing a holy place, meditating, hearing some light music, yoga, ...