In terms of physical health in severe mental illness (SMI), rather than parity we have disparity. People with mental illness receive less screening for breast, cervical and prostate cancer than the general population, less preventive care – such as smoking cessation, in spite of higher rates of smoking – and different standards of treatment. For example, fewer prescriptions for several common medications for medical disorders.

Parity of esteem can be achieved, but it will be a challenge for everyone. Attitude change is important for combating stigma and diagnostic overshadowing, which can raise barriers to treatment. Funding needs to be ring-fenced for equipment, and specific clinical pathways for comorbidity must be developed and commissioned.

Investment in training and education is required, in stigma and diagnostic overshadowing for ‘physical health’ staff and in identifying and monitoring physical conditions for mental health staff.

Parity of esteem is a matter of social justice and fairness because, when access to treatment is unequal, outcomes become unequal too. Mental health nurses need to advocate for the right to equal treatment, which may mean challenging practices.

General life expectancy at birth in the UK in 2021 was about 81. Evidence suggests that people with SMI have a life expectancy 20% lower than those without, which means dying prematurely at about 64, equating to a life expectancy from the 1940s. Surely this is unacceptable in 2023?