Qualitative Secondary Analysis (QSA) is a research method that utilises existing qualitative data to investigate new research questions or to approach topics from a different angle than was addressed by the original or ‘primary’ study. Secondary qualitative data may include oral histories, social media content or public documents. However, the main focus of recent methodological debate has been around the use of archived research data, predominantly qualitative interviews. In this introductory seminar, Dr Annie Irvine and Cassandra Lovelock will briefly describe some key issues and controversies around QSA, the methodological benefits and challenges, and some ethical issues particular to QSA methodology. They will draw on experiences of an ongoing QSA project which is using archived interview data to look at conceptualisation of mental health among people claiming welfare benefits in the UK during the mid-2010s.