This paper uses suicidality in bipolar disorder (BD) as a case study demonstrating the preferability of multidimensional over reductionist frameworks in accounting for complex phenomena with cognitive, psychological, socio-environmental, and physiological components. Suicidality, or behaviors and thoughts concerning an intention to end one’s life, illustrates the interplay between diverse factors. This multidimensionality is reflected in the heterogeneous strategies for managing suicidality, which range from psychosocial and cognitive to pharmaceutical and technological interventions. Suicidality in BD is a multi-dimensional phenomenon whose study has been productive through the methods of several disciplines. For instance, suicidality in BD is partly genetic and can be aggravated by symptomatic periods, suggesting physiological causal factors. However, some features of suicidality in BD underscore the causal roles of cognitions. Notably, suicidality can persist beyond depressive periods, and is sometimes experienced during mania. This may be due to persistent suicidal ideation, highlighting the need to account for cognitive or psychological causal factors. Models of suicidality in BD typically adopt a pluralistic approach that does not reduce one dimension to another. Rather, they are treated as different facets of a complex phenomenon that interact and influence each other. Moreover, recent studies have shown the promise of physical interventions, e.g., electroconvulsive therapy and deep-brain stimulation, in the treatment of suicidality in BD. Socio-environmental interventions have been successful in suicide prevention more generally. This demonstrates how multidisciplinary, multidimensional explanations are most likely to productively account for how diverse factors contribute to suicidality along with genetic and physiological determinants.