The placebo effect is the well-known phenomenon of a person’s physical or mental health improving after taking a treatment with no pharmacological therapeutic benefit – a sugar pill, or a syringe full of saline, for example. While the exact biological, psychological and genetic underpinnings of the placebo effect are not well understood, some theories point to expectations as the primary cause and others argue that non-conscious factors embedded in the patient-physician relationship automatically turn down the volume of symptoms.