The placebo effect is a phenomenon where a person experiences a real improvement in their condition after receiving a treatment that has no therapeutic value, such as a sugar pill or saline injection. This effect occurs because the individual believes they are receiving an effective treatment, which can trigger psychological and physiological responses in the body. Research shows that the placebo effect can influence various conditions, including pain, depression, and anxiety. It highlights the power of the mind in healing and raises important questions about the ethics of using placebos in clinical trials and medical practice, especially when considering patient consent and expectations.