> Placebos work in general as long as the problems are psychological.

There was a study [0] about the placebo effect in heart failure patients: "In a 1999 Swedish Study, doctors implanted an active pacemaker into 40 heart failure patients. Another 40 patients underwent the same surgery, believing they were receiving active pacemakers. But their pacemakers were never turned on: they were, in essence, placebo pacemakers." - [1]

Now as a disclaimer, I did not complete read or understand this study nor do I know if there are counter studies, but it's my favorite bit of information about the placebo effect.

[0] http://www.ncbi.nlm.nih.gov/pubmed/10190407

[1] http://blog.placeboeffect.com/reverse-heart-disease/ (laymen conclusion)

Not really. The placebo effect is real and strong and works even on some maladies that aren't psychosomatic.

Be cautious with the phrase "psychological problems". Placebo seems to work well for pain, and peoe will get very angry if you describe the pain they feel as a psychological problem.

But wishful thinking is a powerful influence, it triggers all sorts of internal processes which may indeed be more powerful and beneficial than medicine. Similarly, religion is nothing more than placebo, but that has influenced (and perhaps benefited) mankind since forever.