Diagnostic overshadowing occurs when symptoms of physical illness are attributed to the service user’s mental illness. This increases the risks of treatment delay and the development of complications. The situation may arise due to stigmatisation of the mental condition and negative attitudes among healthcare practitioners, together with a lack of education and training in physical or mental health, or a lack of confidence in clinical skills and symptom recognition.

Preventing diagnostic overshadowing is challenging because it requires staff to reflect continually on their attitudes, skills and education needs, and practice.