The neurocognitive functioning in bipolar disorder: a systematic review of data

Abstract

Background: During the last decades, there have been many different opinions concerning the neurocognitive function in Bipolar disorder (BD). The aim of the current study was to perform a systematic review of the literature and to synthesize the data in a comprehensive picture of the neurocognitive dysfunction in BD. Methods: Papers were located with searches in PubMed/MEDLINE, through June 1st 2015. The review followed a modified version of the recommendations of the Preferred Items for Reporting of Systematic Reviews and MetaAnalyses statement. Results:The initial search returned 110,403 papers. After the deletion of duplicates, 11,771 papers remained for further evaluation. Eventually, 250 were included in the analysis. Conclusion:The current review supports the presence of a neurocognitive deficit in BD, in almost all neurocognitive domains. This deficit is qualitative similar to that observed in schizophrenia but it is less severe. There are no differences between BD subtypes. Its origin is unclear. It seems it is an enduring component and represents a core primary characteristic of the illness, rather than being secondary to the mood state or medication. This core deficit is confounded (either increased or attenuated) by the disease phase, specific personal characteristics of the patients (age, gender, education, etc.), current symptomatology and its treatment (especially psychotic features) and long-term course and long-term exposure to medication, psychiatric and somatic comorbidity and alcohol and/or substance abuse.

Validity and reliability of the Cognitive Complaints in Bipolar Disorder Rating Assessment (COBRA) in Japanese patients with bipolar disorder

“…Previous work has suggested that some subjective cognitive measures reflect symptoms of depression rather than objective cognitive dysfunction (Svendsen et al, 2012), and that processing speed may be influenced by the adverse effects of medications. However, a recent review paper by Tsitsipa and Fountoulakis (2015) suggests that neurocognitive dysfunction is a core feature of bipolar disorder, as opposed to a secondary outcome of mood symptoms or medication. For example, one study found levels of neurocognitive impairment in patients prior to receiving pharmacological treatment that were similar to those in chronically medicated patients (Nehra et al, 2006).…”

Comparison of cognitive performance in bipolar disorder, major depressive disorder, unaffected first‐degree relatives, and healthy controls

“…Many investigators have reported broad and persistent cognitive deficits in patients with mood disorders overall, and these include BD and MDD . A systematic review of cognitive dysfunction in patients with BD indicated deficits in most cognitive domains . Another study reported that patients with BD were subject to multiple cognitive deficits, especially in attention, executive functioning, verbal memory, and fluency .…”

Consensus paper of the WFSBP Task Force on Biological Markers: Criteria for biomarkers and endophenotypes of schizophrenia part II: Cognition, neuroimaging and genetics

“…Cognitive impairment has been reported in bipolar disorders, particularly in patients with a history of psychotic symptoms (Tsitsipa and Fountoulakis 2015). Whether a generalised deficit exists across a spectrum of psychotic disorders is less clear.…”