The Unseen Burden: Mental Health in Patients with Haematological Malignancies — A Narrative Review

Background Haematological malignancies — including leukaemias, lymphomas, and multiple myeloma — impose a substantial psychological burden on patients that remains systematically underrecognized and undertreated. The complexity of treatment trajectories, prolonged uncertainty, physical debilitation, and existential threat combine to create conditions of exceptional psychological vulnerability. Aim This narrative review synthesizes the evidence on the prevalence, determinants, and clinical consequences of psychiatric comorbidity in patients with haematological malignancies, and examines the evidence base for psychological and pharmacological interventions in this population. Methods A narrative review of peer-reviewed literature published through December 2024 was conducted using PubMed, PsycINFO, and CINAHL. Relevant studies, systematic reviews, and clinical guidelines were identified using search terms combining haematological malignancies, blood cancers, leukaemia, lymphoma, myeloma, with depression, anxiety, PTSD, quality of life, psycho-oncology, and psychological intervention. Results Depression affects 20–40% and anxiety disorders 25–50% of patients with haematological malignancies, with rates varying by disease type, treatment phase, and sociodemographic factors. Psychological distress is independently associated with worse treatment adherence, reduced quality of life, and poorer survival outcomes. Bone marrow transplantation is associated with particularly high rates of post-traumatic stress, depression, and cognitive impairment. Evidence-based psychological interventions — including cognitive behavioural therapy, mindfulness-based approaches, and meaning-centred psychotherapy — demonstrate efficacy in this population, yet access remains severely limited globally. Conclusions Mental health comorbidity in haematological malignancy is prevalent, clinically significant, and inadequately addressed by existing oncological care systems globally. Integrating systematic psychological screening and evidence-based support into haematology services represents both a clinical and an ethical imperative.