Universal Credit (UC) is harmful to the mental health of claimants and has a particularly detrimental impact on the mental health of lone parents, creating stress, anxiety and financial hardship. This rapid response briefing shares findings from the Changing Realities research programme, which works in partnership with over 100 parents and carers living on a low income from across the UK. It combines quantitative analysis of the mental health impacts of UC with the accounts of lone parents and carers, charting their experiences of navigating UC and the additional challenges of doing so without the financial and emotional support that can come from a partner.