Informing National Health Service patients about participation in clinical research: A comparison of opt-in and opt-out approaches across the United Kingdom.

Findings suggest that 'opt-out' is more beneficial than 'opt-in', with the potential to vastly increase patient access to research opportunities and to enable greater equality of information provision for currently marginalised groups. This should ensure that healthcare research is more representative of the entire population, including those with a mental health diagnosis.