David rosenhan sent "pseudopatients" to a mental hospital, where they pretended to be disturbed. the results led him to conclude that greatly impacts mental illness.

The results led him to conclude that labeling greatly impacts mental illness.

Labeling refers to the terms and definitions we use to describe ourselves and others. They can have both a positive and negative effect on people. For example when it comes to illness, when you are diagnosed with a health condition that condition becomes a label that can alter your perception of how you view yourself, you come to define yourself in terms of that illness which can have a negative impact on your outlook on life and can physically alter and even make your health worse.