Background: Major depressive disorder (MDD) and bipolar disorder (BD) are mood disorders associated with cognitive impairment and reduced psychosocial functioning. Although BD is often assumed to involve more severe functional difficulties which warrant specific attention during treatment, evidence remains inconsistent, and it is unclear whether meaningful differences exist between the disorders. Clarifying whether MDD and BD show distinct or overlapping profiles is essential to inform more precise and effective treatment strategies, particularly for the lesser recognised cognitive profile of MDD.
Aims and Hypotheses: The project aims to synthesise existing research comparing cognitive and psychosocial outcomes in adults with MDD and BD. The primary objectives are to determine the extent and pattern of deficits in each disorder and to examine how demographic, clinical, and treatment-related factors influence these differences.
A secondary objective is to explore how cognitive and psychosocial functioning vary across illness stages (e.g., current depressive state, remitted state). Based on current evidence, it is anticipated that individuals with BD may demonstrate greater deficits in select, objective cognitive domains, such as executive function, relative to MDD, whereas subjective cognitive difficulties and psychosocial deficits may be more comparable across the conditions. Factors such as age and depressive symptom severity will likely help explain the differences in profiles.
Proposed project: The student will join the research team to support completion of the systematic review by screening studies, conducting quality assessments, extracting and organising data, and contributing to data synthesis and manuscript preparation.
Expected contribution: The project, to the best of our knowledge, will be the first systematic review to provide a comprehensive synthesis of cognitive and psychosocial functioning in MDD versus BD, providing relevant insights to refine our understanding of how mood disorders affect functioning and to support targeted intervention approaches.