This refers to the phenomenon wherein a patient undergoing medical treatment may suffer from negative side effects purely due to her own negative expectations. This is in contrast to the placebo effect where a patient enjoys better health due to positive expectations regarding her treatment. Negative psychological expectations are believed to cause physiological changes in a patient’s body, leading to negative health effects. Scientists have that found that patients who were warned about negative side effects of a certain medicine actually suffered these side effects even though they were only served harmless fake pills.