Exploring the Association between Monoclonal Antibodies and Depression and Suicidal Ideation and Behavior: A VigiBase Study

Introduction: Several monoclonal antibodies (mAbs) have been linked to neuropsychiatric adverse efects in patients, including depression and suicidal ideation and behavior. Objective: The aim of this study was to quantify and characterize spontaneously reported adverse drug reactions (ADRs) of depression and suicidal ideation and behavior related to mAb users, and to explore a possible association with their mechanism of action. Methods: We included mAb ADRs that were reported in VigiBase, and identifed those related to depression and suicidal ideation and behavior. Reporting odds ratios (RORs) were estimated for each mAb (bevacizumab as the reference) and according to their infuence on the immune system (not directly targeting [reference], stimulating, or suppressing). Those suppressing the immune system were further divided into their intended indication (auto-immune diseases, cancer). Results: Overall, 2,924,319 ADRs for 44 mAbs were included; 9455 ADRs were related to depression and 1770 were related to suicidal ideation and behavior. The association was strongest for natalizumab and belimumab, both for depression (ROR 5.7, 95% confdence interval [CI] 5.0–6.4; and ROR 5.1, 95% CI 4.2–6.2) and suicidal ideation and behavior (ROR 12.0, 95% CI 7.9–18.3; and ROR 20.2, 95% CI 12.4–33.0). Those suppressing the immune system showed higher ROR, i.e. 1.9 (95% CI 1.8–2.0) for depression and 3.6 (95% CI 3.0–4.4) for suicidal ideation and behavior. This fnding was only seen for mAbs used for treating autoimmune diseases. Conclusion: Depression and suicidal ideation and behavior are seen in patients using mAbs, particularly mAbs used for treating autoimmune diseases that suppress the immune system. For interpretation of these data, the indications for use and other characteristics require further consideration.