In the UK, approximately 1.18 million people are accessing secondary mental health services, of which 136,00 have a serious mental health condition, such as psychosis or bipolar disorder. These mental health disorders are some of the most commonly reported working-age disabilities and an often-cited reason for claiming unemployment and sickness-related benefits. During the past decade, substantial changes have been made to the benefit system such as the introduction of the “Universal Credit” benefit to replace several other benefits. There are concerns around the impact of these changes on particularly vulnerable claimants including people affected by mental health disorders, yet there is a lack of evidence on the profiles of these benefit claimants and the types of interventions and support programs that are most and least helpful for helping this group gain and remain in work. This project aims to explore the complex relationships between employment status, social welfare and benefit receipt among people with mental health disorders using linked data from the Department for Work and Pensions (DWP) and the Work and Health Unit and NHS mental health medical records from secondary care services in South London and Maudsley (SLAM), providing a unique data set of 400,000 working age adults. The first research question will explore whether information on diagnosis for benefit claims to the DWP taken from GPs is consistent with secondary care service mental health data. I will explore the correspondence between benefit claim descriptions in the DWP data compared to diagnoses recorded in the SLaM data. The second research question will look at the changes to the benefit system such as the introduction of Universal credit (UC) and how this impacts the amount of benefits received and time spent on benefits before returning to work. The third research question will assess which sociodemographic factors such as ethnicity and age impact the number and type of benefits received, and time spent 3 / 14 on benefits. I will also explore what types of mental health interventions and support provided by both SLaM and DWP are available and improve return to work, and how this differs by diagnosis, ethnicity and age. Finally, I will conduct interviews to find out about the facilitators and barriers people with serious mental health disorders experience in returning to work or finding suitable alternatives, and whether they feel adequately supported. Findings will provide knowledge around what is required and most appropriate to help people affected by a range of mental health disorders to gain and maintain work or find suitable alternatives. Together with the patient and public involvement group and stakeholders I will develop practical recommendations based on the findings in order to improve upon policies relating to benefit receipt. The findings will be published in scientific journals. Findings will also be summarised using clear info-graphics that will be shared via social media and I will attend public speaking events, conferences, and community gatherings to ensure my research is disseminated widely.