Cognitive Dysfunctions in Bipolar Disorder: Evidence of Neuropsychological Disturbances

Abstract

Although cognitive dysfunctions in psychosis have classically been associated with schizophrenia, there is clinical evidence that some bipolar patients show cognitive disturbances either during acute phases or in remission periods. The authors critically review the data on cognitive impairment in bipolar disorder. The main computerized databases (Medline, Psychological Abstracts, Current Contents) have been consulted crossing the terms ‘cognitive deficits’, ‘neuropsychology’, ‘intellectual impairment’, ‘mania’, ‘depression’ and ‘bipolar disorder’. Changes in the fluency of thought and speech, learning and memory impairment, and disturbances in associational patterns and attentional processes are as fundamental to depression and mania as are changes in mood and behavior. Moreover, a significant number of bipolar patients show persistent cognitive deficits during remission from affective symptoms. However, there are several methodological pitfalls in most studies such as unclear remission criteria, diagnostic heterogeneity, small sample sizes, absence of longitudinal assessment, practice effect and poor control of the influence of pharmacological treatment. Most studies point at the presence of diffuse cognitive dysfunction during the acute phases of bipolar illness. Most of these deficits seem to remit during periods of euthymia, but some of them may persist in approximately one third of bipolar patients. Methodological limitations warrant further research in order to clear up the relationship between neuropsychological functioning and clinical, demographic and treatment variables in bipolar disorder.

Pronounced Cognitive Deficits Following an Intravenous L-Tryptophan Challenge in First-Degree Relatives of Bipolar Patients Compared to Healthy Controls

“…Cognitive impairments have previously been described in FH and also in manic, depressed, and euthymic BD patients (Sobczak et al, 2002c;Rossi et al, 2000;Martinez-Aran et al, 2000;Ferrier et al, 1999;Murphy et al, 1999;Rubinsztein et al, 2000). The cognitive deficits in BD may be partially explained by abnormalities in functional brain structures and/or metabolism (Stoll et al, 2000;Manji et al, 2000;van Gorp et al, 1999;Coffman et al, 1990).…”

Elevated Concentrations of Neurofilament Light Chain in the Cerebrospinal Fluid of Bipolar Disorder Patients

“…The first-line mood-stabilizing treatments include lithium, divalproex, olanzapine, and lamotrigine (the latter mainly for those with mild manias) (Yatham et al, 2009). BD has also been coupled to cognitive impairment including reduced abilities in executive function and verbal memory (Martinez-Aran et al, 2000;Zarate et al, 2000;Martinez-Aran et al, 2005;Robinson et al, 2006;Sanchez-Moreno et al, 2009;Palsson et al, 2013). Structural imaging studies have suggested that the decline in cognitive function is associated with morphological abnormalities of the brain (Altshuler et al, 1995;McDonald et al, 2004;Kempton et al, 2008;Konarski et al, 2008), and that the number of manic episodes is associated with decreased gray matter in dorsolateral prefrontal cortex (Ekman et al, 2010).…”

İki̇ Uçlu Duygudurum Bozukluğu Tanili Hastalarin Depresyon, Eşi̇kalti Depresyon Ve İyi̇li̇k Dönemleri̇ni̇n Nöropsi̇koloji̇k Açidan Karşilaştirilmasi

“…Yazında, bizim çalışmamızdakine benzer şekilde depresif dönemde yürütücü işlev (8,33,34), sözel bellek (34,36), görsel bellek ve mekansal bellekte (36,37) bozulmalar bildirilmiştir. Bununla birlikte iyilik ve depresyon dönemindeki İUDB olan hastaları doğrudan karşılaştıran az sayıda çalışma vardır (38).…”

“…Hastalık dönemlerinin dışında, İUDB'nun iyilik dönemindeki hastalar üzerinde yapılan çalış-malarda da, hastaların bilişsel test sonuçlarının sağlıklı kontrollere göre bozulmuş olduğuna işaret edilmektedir (5,6,7,8,9,10). Ancak İUDB tanılı hastalarda bilişsel işlevlerle ilişkili araş-tırmaların sonuçları eşik altı belirtilerin varlığı dolayısıyla kafa karıştırıcıdır (9,11,12,13).…”