This is an Act of Parliament which applies in England and Wales and came into force in April 2007. Its primary purpose is to provide a legal framework for acting and making decisions on behalf of adults who lack the capacity to make particular decisions for themselves. Prior to the Act such decisions were made under common law and guided by previous case law. This led to uncertainty in the rights and legal protection of patients and treating doctors alike.
Mental Capacity legislation
Link to blog posts featuring legislation as it applies to mental health/illness
— A video from the BMA about the Mental Capacity Act
— A short video reminder of the five principles in the MCA