While I accept that some people suffer from migraines I do not believe it is as prevalent as it seems. I think that too many people confuse a bad headache with a migraine. I just tell people I don't believe in the condition; as a consequence the sickness rates in my department are about a quarter of that for the organisations I have worked for as a whole.
Similarly everyone used to have RSI and then that died down and was replaced with Chronic Fatigue Syndrome and then that died down and has been replaced with Depression. I personally think that they have all been overstated and, realistically, in twenty years of working I can only think of two people who had genuine RSI and one person with genuine depression. The rest were either trying to avoid work or were overstating their condition in order to get attention. I can just imagine how much worse it must be for a doctor who would see it on an hourly basis. People are convinced that if there is something wrong with them that it is the most serious thing possible and that they need to be booked into intensive care immediately. I imagine that most of these doctors prescribing placebos are doing so in order to get these people out of their clinics so that they can help people with real problems.