Symptom Burden and Quality of Life in Patients With Severe Mental Disorders Initiating Cancer Treatment

BACKGROUND: Patients with pre-existing severe mental disorders (SMDs), defined as moderate to severe depression, bipolar disorder, or schizophrenia, face barriers to optimal cancer care and may experience elevated mental and physical symptom burden and reduced quality of life. AIMS: To assess health-related quality of life (HRQoL) and psychiatric symptom burden among patients with SMD before initiating cancer treatment. METHODS: In this case-control study, 120 patients with lung, breast, or head and neck cancer were included. The patients were matched 1:2 with controls without SMD, using sex, age (±5 years), cancer type, and treatment intent. Recruitment occurred at the first oncology visit (January 2023-June 2025). HRQoL and psychiatric symptoms were measured using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core-15 Palliative and Symptom Checklist-92 questionnaires. Patient characteristics were extracted from electronic medical journals. Means with confidence intervals (CI) and mean ratios were calculated to compare the two groups. RESULTS: Patients with cancer and pre-existing SMD reported significantly poorer HRQoL than matched controls, with a mean of 56.67 (95% CI 48.75-64.58), compared to patients without SMD (mean: 69.01 (95% CI: 65.20-72.90)). Similarly, both physical and emotional functioning were lower in the SMD group, and the psychiatric symptom burden was substantially higher among patients with SMD. CONCLUSIONS: Patients with cancer and pre-existing SMD initiate cancer treatment with substantially poorer HRQoL, higher emotional and physical symptom burden, and markedly elevated psychiatric symptom burden compared with controls. These findings highlight the need for early, integrated psychiatric and supportive care to improve outcomes in this high-risk group.