Even though pseudodementia has been historically linked to depression, other psychiatric conditions may cause reversible cognitive alterations. The purpose of this study is to improve our understanding of pseudodementia occurring throughout the entire bipolar spectrum. A systematic review was conducted according to PRISMA guidelines. PubMed, Scopus, and Web of Science databases were searched up to March 2023. Fifteen articles on patients with pseudodementia and bipolar disorder (BD), mania, hypomania, or mixed depression have been included. Moreover, seven female patients with mood disorders diagnosed with pseudodementia have been described. According to our research, pseudodementia in patients with BD mostly occurs during a depressive episode. However, pseudodementia has also been observed in the context of manic and mixed states. Psychomotor and psychotic symptoms were commonly associated. The most typical cognitive impairments were disorientation, inattention, and short-term memory deficits. Alterations in neuroimaging were frequently observed. Electroconvulsive therapy and lithium, either alone or in combination with antipsychotics, resulted in the most widely used therapies. Cognitive decline may occur in a substantial proportion of patients. Since pseudodementia can manifest along the entire mood spectrum, it should be taken into consideration as a possible diagnosis in BD patients showing cognitive deficits during manic, mixed, and depressive states.
Keywords: bipolar disorder; bipolar spectrum; cognitive reserve; depressive pseudodementia; manic pseudodementia; mood spectrum; neurodegeneration; predementia; pseudodementia; reversible dementia.