Despite mounting calls to increase the involvement of people with lived experience in global mental health (GMH) research, there are few examples from low- and middle-income countries (LMICs). This thesis draws on a Theory of Change-driven evaluation of the Brain Gain II peer support project at Butabika Hospital in Kampala, Uganda, to document and derive lessons from efforts to involve peer workers at various stages of the research process. This is a paper-style thesis comprising three published articles and two manuscripts under preparation. First, an 18-month rapid review reports an increase in the rate of publication on involvement in mental health systems strengthening in LMICs, but identifies only one possible example of involvement in the actual conduct of research. Second, a critical review of the literature on psychosis in sub-Saharan Africa highlights the material consequences of exclusion from GMH research. Third, a protocol documents how peer workers were involved in conceptualising and collecting data for a quasi-experimental study evaluating the effectiveness of Brain Gain II’s peer support. The fourth paper shares findings of the Brain Gain II knowledge, attitudes and practices survey, which was developed in collaboration with peer workers. Finally, a qualitative study explores the benefits and unintended consequences of efforts to involve peer workers in data collection for Brain Gain II. This thesis demonstrates that it is possible to involve people with lived experience in carrying out mental health research in a low-resource setting and highlights a number of possible benefits. However, Brain Gain II peer workers were often in exceptionally vulnerable situations, skirting a fine line between empowerment and exploitation. GMH research projects that seek to involve people with lived experience should critically reflect on how involvement is ultimately experienced and share their insights in order to avoid either "reinventing the wheel" or repeating past mistakes.