The lived experience of major and treatment-resistant depression in England: a mixed-methods study

Introduction: Major depressive disorder (MDD) is a common, frequently recurrent condition associated with decreased well-being and increased healthcare-related costs. Mixed-methods research provides multiple ways of illustrating the phenomenon to better understand patient experience, including where treatment is not working, referred to here as treatment-resistant depression (TRD). Methods: A mixed-methods study investigated the experiences of people with symptomatic MDD, symptomatic TRD or TRD in remission, surveying 148 adults recruited from English clinical sites to measure symptom severity (Patient Health Questionnaire-9 [PHQ-9]), HRQoL (EQ-5D-5L/World Health Organisation Brief Assessment of QoL [WHOQOL-BREF]) and work productivity/activity impairment (WPAI:D). Interviews with 26 survey respondents were analysed thematically. Integrated datasets explored areas of convergence and divergence, with concepts mapped against the EQ-5D-5L. Results: Qualitative data explained low WHOQOL-BREF domain scores and the interrelation of psychological, emotional, cognitive and physical difficulties. Tiredness, lack of energy and motivation impacted daily activities, socialising and career goals. Low work performance scores were explained by poor concentration, decisionmaking and motivation. Participants also described the influence of social support and housing insecurity. Only 19 % of HRQoL qualitative codes mapped to the EQ-5D-5L. Themes dominant in patients with TRD were inability to cope, self-care challenges, dissatisfaction with mental health services and treatment pessimism. Limitations: Limited data collected on people with TRD in remission. Conclusions: The EQ-5D-5L and WPAI:D likely underestimate how depression impacts the HRQoL and work of people with MDD or TRD. Qualitative data suggest increased distress for people with TRD compared to those with MDD. Clinical management and treatment access decisions should consider the broader impacts of depression and environmental factors affecting the patient's experience.