|Year : 2014 | Volume
| Issue : 3 | Page : 133-137
Neuropsychological cognitive dysfunctions in psychotic bipolar disorders
Nagy Fawzy, Usama M Youssef, Amira A Fouad
Department of Psychiatry, Zagazig University, Zagazig, Egypt
|Date of Web Publication||11-Nov-2014|
Department of Psychiatry, Zagazig University, Zagazig, Sharkya
Source of Support: None, Conflict of Interest: None
The aim of this study was to determine neuropsychological cognitive dysfunctions in psychotic bipolar disorders and compare the results with a control group.
Participants and methods
The sample included two groups: group I included 20 psychotic bipolar patients recruited from psychiatric outpatient clinics of Zagazig University Hospitals. Group II included 20 participants selected randomly from Zagazig University Hospitals visitors. Patients were subjected to a semistructured psychiatric interview using the DSM-IV criteria for psychotic bipolar diagnosis, detection of mania by Young mania rating scale for the study group, and detection of neuropsychological cognitive function, where executive functions were assessed using the Wisconsin card sorting tests and memory was assessed using the Wechsler memory scale.
The results of the current study indicated a highly significant difference between psychotic bipolar patients and the control group in executive functions, logic memory, digit span forward, digit span backward, associative learning, and total memory, and a reversible highly significant correlation between the number of hospitalizations and cognitive functions in psychotic bipolar patients for block design.
The current study concluded that neuropsychological cognitive dysfunctions are highly prevalent in psychotic bipolar disorders and it is strongly inter-related with sociodemographic and clinical characteristics.
Keywords: cognitive dysfunction, neuropsychological, psychotic bipolar disorder
|How to cite this article:|
Fawzy N, Youssef UM, Fouad AA. Neuropsychological cognitive dysfunctions in psychotic bipolar disorders. Egypt J Psychiatr 2014;35:133-7
| Introduction|| |
A major challenge facing the developers of the DSM-V and a topic of considerable debate in the literature is whether schizophrenia and psychotic bipolar disorders are separate and distinct disorders or whether they occur on a 'psychosis' continuum (Allardyce et al., 2007). Some experts define this continuum as a spectrum of psychotic disorders with mood disorders, such as bipolar disorder with psychotic features, on one pole and schizophrenia on the other pole, with schizoaffective disorder in the middle (Lake and Hurwitz, 2007). Among psychotic bipolar disorders, schizophrenia is the second most common misdiagnosis (Hirschfeld et al., 2003). The consequences of misdiagnosing psychotic bipolar disorder as a psychotic disorder can be severe. Such a misdiagnosis might lead to ineffective or even harmful treatment (Bowden, 2004; Muzina and Calabrese, 2005). One of the most difficult aspects of this debate is the neuropsychological cognitive aspects. Overlapping neuropsychological deficits have been reported in schizophrenia and psychotic bipolar disorders and in their unaffected relatives (Pirkola et al., 2005; Daban et al., 2006; Reichenberg et al., 2008). These overlapping cognitive deficits as well as persistent cognitive and functional impairments observed in psychotic bipolar disorder raise questions about the classic Kraepelinian model by suggesting more similarities in persistent functional deficits across the disorders (Tabares-Seisdedos et al., 2008). Actually, in recent decades, many studies have reported that neurocognitive impairments are a fundamental part of schizophrenia because they are prevalent and severe, are not secondary to medication, institutionalization or symptoms, are present before or at the onset of illness, and are mainly stable over time (Elvevag and Goldberg, 2000). Moreover, cognitive deficits are a superior predictor of outcome than symptoms of schizophrenia (Eyler et al., 2008). Neuropsychological cognitive deficits are especially pronounced in the domains of verbal memory, executive functioning, and attention (Savilla et al., 2008), and less attenuated in the domains of perceptual and basic language processes (Heinrichs and Zakzanis, 1998). Among psychotic bipolar disorders, it was widely accepted that cognitive abnormalities in bipolar disorder are mild, transitory, and limited to affective episodes (Malhi et al., 2004). However, accumulating evidence has cast doubt on the Kraepelinian notion (Kraepelin, 1913) that bipolar disorder, unlike schizophrenia, is not characterized by cognitive decline (Martinez-Aran et al., 2004). Recently, studies assessing cognition in psychotic bipolar patients have confirmed the presence of cognitive deficits remaining stable over at least a 3-year period (Balanzα-Martνnez et al., 2005). Moreover, impairments in almost all cognitive domains (but more evident in verbal memory and some executive functions) have been reliably documented in psychotic bipolar.
| Participants and methods|| |
This study was carried out in psychiatry outpatient clinics of Zagazig University Hospitals in the period between 1 April 2013 and 1 January 2014. The sample included two groups. Group I included 20 psychotic bipolar patients recruited from psychiatric outpatient clinics of Zagazig University Hospitals. To be included in the study, patients had to fulfill the DSM-IV-TR criteria for psychotic bipolar, in remission for at least 6 months, ranging in age from 20 to 40 years, both sexes, without a history of electro-convulsive therapy (ECT), and from all socioeconomic and educational classes. The exclusive criteria were patients with other psychiatric or physical disorders, mental retardation, substance dependence, history of head injury, and gross neurological disorder. Group II included 20 participants selected randomly from among visitors to Zagazig University Hospitals, matched in age, sex, and social classes and without a history of psychiatric or physical disorders.
An informed written consent was obtained from all participants. Patients were subjected to a semistructured psychiatric interview using the DSM-IV criteria for psychotic bipolar diagnosis. Sociodemographic data on age, sex, education, marital status, and employment status were collected. Detection of mania was performed using the Young mania rating scale (Young et al., 2004). The scale includes 11 items and is based on the patient's subjective report; each item is assigned a severity rating. There are well-described anchor points for each grade of severity. Neuropsychological cognitive function and executive functions were assessed using the Wisconsin card sorting test (WCST) (Heaton et al., 2003); it assesses abstract reasoning ability and the ability to shift cognitive strategies in response to changing environmental contingencies (Reitan, 1958), and consists of four stimulus cards and 128 response cards. WCST1 describes the total number of categories completed by the patient within the 128 cards matched. WCST2 describes the total perseveration errors made by the patient while matching the 128 cards (Heaton et al., 1993). Memory was assessed using the Wechsler memory scale (Wechsler, 1987); it includes information and orientation questions, eight short-term memory tasks and four delayed recall trials, all of which take about 45 min to 1 h to administer. The eight tests of short-term memory contribute toward five composite scores or indexes equivalent statistically to IQ scores with means of 100 and SDs of 15.
χ2 -test was used to compare the sociodemographic characteristics of the study between groups.
where ∑ is summation, O is the observed value, and E is the expected value.
The analysis of variance (f), Pearson's correlation coefficient correlation, were assessed and analyzed by a personal computer using the statistical software program SPSS (version 13) (SPSS, 2002).
| Results|| |
The results of the current study were as follows: [Table 1] shows the sociodemographic and clinical characteristics of both groups. [Table 2] shows that psychotic bipolar patients performed worse than the control group on trail A (trail A making test) and trail B (trail B making test), and the difference was highly significant, where WCST means Wisconsin card sorting test 'category completion' and WCST2 means Wisconsin card sorting test 'perseveration errors'. [Table 3] shows that psychotic bipolar patients performed worse than the control group, and the difference was highly significant for logic memory, digit span forward, digit span backward, associative learning, and total memory. [Table 4] shows that the correlation between the age of illness onset and cognitive functions in psychotic bipolar patients is not significant. [Table 5] shows a reversible highly significant correlation between the number of hospitalizations and cognitive functions in psychotic bipolar patients in block design. [Table 6] shows no significant correlation between the total length of hospitalizations and cognitive functions in psychotic bipolar patients. [Table 7] shows no significant correlation between the Young mania rating scale score and cognitive functions in psychotic bipolar patients, where P value less than 0.05 means significant and P value less than 0.01 means highly significant.
|Table 1 Sociodemographic and clinical characteristics of the study groups|
Click here to view
|Table 2 Comparison between psychotic bipolar patients and the control group in executive functions|
Click here to view
|Table 3 Comparison between psychotic bipolar patients and control group in memory|
Click here to view
|Table 4 Correlation between the age of illness onset and cognitive functions in psychotic bipolar patients|
Click here to view
|Table 5 Correlation between the number of hospitalizations and cognitive functions in psychotic bipolar patients|
Click here to view
|Table 6 Correlation between the total length of hospitalizations and cognitive functions in psychotic bipolar patients|
Click here to view
|Table 7 Correlation between Young mania rating scale score and cognitive functions in psychotic bipolar patients|
Click here to view
| Discussion|| |
The aim of the present study was to study objectively neuropsychological cognitive functioning of patients with psychotic bipolar disorder. The neuropsychological cognitive dysfunctions studied in this study were chosen on the basis of the results of multiple studies that showed that the most commonly affected cognitive domains in case of schizophrenia and psychotic bipolar disorder were memory, executive functions, and attention (Reichenberg et al., 2008; Pietrzak et al., 2010; Brissos et al., 2011). For psychotic bipolar disorder, it was believed that cognitive abnormalities were mild, transitory, and limited to the affective episodes (Malhi et al., 2004; Potter et al., 2010). However, studies assessing cognition in psychotic bipolar patients had confirmed the presence of cognitive deficits (Zubieta et al., 2001), remaining stable over at least a 3-year period (Balanzα-Martνnez et al., 2010). Moreover, impairment in almost all cognitive domains (but more evident in verbal memory and some executive functions) had been documented in psychotic bipolar patients (Quraishi and Frangou, 2002). For the executive functions and attention, psychotic bipolar patients performed worse than the healthy control group as tested by trail A, trail B, and WCST. Also, several previous studies had reported greater impairment in executive functioning among euthymic patients with a history of psychosis (Martinez-Aran et al., 2004; Park et al., 2004). In fact, it could be that previous psychotic episodes contributed toward the impairment in cognitive functioning observed in the future. At the same time, it was notable that the impairment was highly significant even after controlling for certain variables that would be related to the overall severity of illness [i.e. number of admission; (Levy and Weiss, 2010)]. In terms of memory, psychotic bipolar patients performed worse than the healthy control group as tested by the Wechsler memory scale. Given that acute mania was associated with the dysregulation of a multitude of brain systems, it was perhaps not surprising that memory was also impaired. Although the general assumption in the past was that memory recovered with resolution of the acute phase of illness, evidence suggested that the functional recovery of all memory systems was not complete (Ferrier et al., 2004). The impact of affective disorders on certain aspects of memory was considerable, detectable even in the euthymic or asymptomatic phase of the. In agreement with the study, Thompson et al. (2005) found that euthymic patients performed poorer than healthy controls, especially in verbal memory. Moreover, Martinez-Aran et al. (2004) found greater impairment in verbal memory in bipolar patients with a history of psychosis compared with both healthy controls and bipolar patients without a history of psychosis patients, independent of their current clinical state. Also, Thompson et al. (2005) found greater impairment in verbal memory among euthymic patients with a history of psychosis. In contrast to the study, Albus et al. (1996) did not find a significant difference in logical memory between euthymic patients with a history of psychosis and healthy controls; however, they found that performance on tests of associative learning was poorer in euthymic psychotic bipolar disorder (PBD) patients relative to controls, which was not in agreement with our study. For working memory, our findings were different from the study of Albus et al. (McGrath et al., 2001), who concluded that independent of psychosis, nondepressed, first-episode bipolar patients performed equivalently to healthy controls. This difference could be explained by elimination of the effect of a history of psychosis and short duration of illness in the previous study. However, the findings supported the evidence that bipolar disorder with psychotic features might represent a distinct subgroup of bipolar disorder with working memory impairments that were similar to patients with schizophrenia (McGrath et al., 2001).
| Conclusion|| |
The current study concluded that cognitive dysfunction is present in psychotic bipolar disorder patients and it is strongly inter-related with sociodemographic and clinical characteristics.
The study recommends that cognitive dysfunctions should be considered as a trait marker, predicting and prognostic factor of patients presented in psychotic bipolar disorder, increase awareness of caregivers and families to cognitive dysfunction un their patients, and more research on the families of affected patients to find out more cognitive markers for illnesses.
| Acknowledgements|| |
| References|| |
Albus M, Hubmann W, Wahlheim C, Sobizack N, Franz U, Mohr F (1996). Contrasts in neuropsychological test profile between patients with first episode schizophrenia and first episode affective disorder. Acta Psychiatr Scand 94:87-93.
Allardyce J, Gaebel W, Zielaske J, van Os J (2007). Deconstructing psychosis conference February 2006: the validity of schizophrenia and alternative approaches to the classification of psychosis. Schizophr Bull 33:863-867.
Balanzá-Martínez V, Tabarés-Seisdedos R, Selva-Vera G, Martínez-Arán A, Torrent C, Leal-Cercós C, et al
. (2005). Persistent cognitive dysfunctions in bipolar I disorder and schizophrenic patients: a 3-year follow-up study. Psychother Psychosom 74:113-119.
Balanzá-Martínez V, Selva G, Martínez-Arán A, Prickaerts J, Salazar J, González-Pinto A, et al
. (2010). Neurocognition in bipolar disorders - a closer look at comorbidities and medications. Eur J Pharmacol 626:87-96.
Bowden CL (2004). Making optimal use of combination pharmacotherapy in bipolar disorder. J Clin Psychiatry 65(Suppl 15):21-24.
Brissos S, Palhavã F, Marques JG, Mexia S, Carmo AL, Carvalho M, et al
. (2011). The Portuguese version of the Personal and Social Performance Scale (PSP): reliability, validity, and relationship with cognitive measures in hospitalized and community patients. Soc Psychiatry Psychiatr Epidemiol 47:1077-1086.
Daban C, Martinez-Aran A, Torrent C, Balanza-Martinez V, Salazar-Fraile J, Selva-Vera G, Vieta E (2006). Specificity of cognitive deficits in bipolar disorder versus schizophrenia. A systematic review. Psychother Psychosom 75:72-84.
Elvevag B, Goldberg TE (2000). Cognitive impairment in schizophrenia is the core of the disorder. Crit Rev Neurobiol 14:1-21.
Eyler LT, Jeste DV, Brown GG (2008). Brain response abnormalities during verbal learning among patients with schizophrenia. Psychiatry Res 162:11-25.
Ferrier IN, Chowdhury R, Thompson JM, Watson S, Young AH (2004). Neurocognitive function in unaffected first-degree relatives of patients with bipolar disord: a preliminary report. Bipolar Disord 6:319-22.
Heaton RK, Chelume CJ, Talley J, Kay GG, Curtis G (1993). Wisconsin card sorting test revised and expanded. Psychological Assessment Resources Inc, Odessa, FL.
Heaton RK, Chelune GJ, Talley JL, et al
. (2003). Computerised Wisconsin Card Sort Task version 4 (WCST). Psychological Assessment Resources Inc.
Heinrichs RW, Zakzanis KK (1998). Neurocognitive deficit in schizophrenia: a quantitative review of the evidence. Neuropsychology 12:426-445.
Hirschfeld RMA, Lewis L, Vornik LA (2003). Perceptions and impact of bipolar disorder: how far have we really come? Results of the national depressive and manic-depressive association 2000 survey of individuals with bipolar disorder. J Clin Psychiatry 64:161-174.
Kraepelin, E. (1913) Lectures on Clinical Psychiatry, edited by T. Johnstone, 3rd English ed. (New York: William Wood and Co.; reprinted, Bristol: Thoemmes Press, 2002); originally published in 1905 as Einführung in die Psychiatrische Klinik. Zweiunddreißig Vorlesungen, 2nd ed.
Lake CR, Hurwitz N (2007). Schizoaffective disorder merges schizophrenia and bipolar disorder as one disease - there is no schizoaffective disorder. Curr Opin Psychiatry 20:365-379.
Levy B, Weiss RD (2010). Neurocognitive impairment and psychosis in bipolar I disorder during early remission from an acute episode of mood disturbance. J Clin Psychiatry 71:201-206.
Malhi GS, Cahill C, Ivanovski B, Szekeres V, et al
. (2004). Bipolar disorder: it's all in your mind? The neuropschological profile of a biological disorder. Can J Psychiatry 49:813-819.
Martinez-Aran A, Vieta E, Reinares M, Colom F, Benabarre A, Goikolea JM, et al
. (2004). Cognitive function across manic or hypomanic, depressed, and euthymic states in bipolar disorder. Am J Psychiatry 161:262-270.
McGrath J, Chapple B, Wright M (2001). Working memory in schizophrenia and mania: correlation with symptoms during the acute and subacute phases. Acta Psychiatr Scand 103:181-188.
Muzina DJ, Calabrese JR (2005). Maintenance therapies in bipolar disorder: focus on randomized controlled trials. Aust N Z J Psychiatry 39:652-661.
Park N, Juo SH, Cheng R, Liu J, Nee J, Grunn A, et al
. (2004). Linkage analysis of psychosis in bipolar pedigrees suggests novel putative loci for bipolar disorder and shared susceptibility with schizophrenia. Mol Psychiatry 9:1091-1099.
Pietrzak RH, Snyder PJ, Maruff P (2010). Use of an acute challenge with d-amphetamine to model cognitive improvement in chronic schizophrenia. Hum Psychopharmacol 25:353-358.
Pirkola T, Tuulio-Henriksson A, Glahn D, Haukka J, Kaprio J, Lonnqvist J, Cannon TD (2005). Spatial working memory function in twins with schizophrenia and bipolar disorder. Biol Psychiatry 58:930-936.
Potter MC, Elmer GI, Bergeron R, Albuquerque EX, Wu HQ, Schwarcz R (2010). Reduction of endogenous kynurenic acid formation enhances extracellular glutamate, hippocampal plasticity, and cognit
ive behavior. Neuropsychopharmacology 35:1734-1742.
Quraishi S, Frangou S (2002). Neuropsychology of bipolar disorder: a review. J Affect Disord 72:209-226.
Reichenberg A, Harvey PD, Bowie CR, Mojtabai R, Rabinowitz J, Heaton RK, Bromet E (2008). Neuropsychological function and dysfunction in schizophrenia and psychotic affective disorders. Schizophr Bull 35:1022-1029.
Reitan RM (1958). Validity of the trail making test as an indicator of organic brain damage. Percept Mot Skills 8:271-276.
Savilla K, Kettler L, Galletly C (2008). Relationships between cognitive deficits, symptoms and quality of life in schizophrenia. Aust N Z J Psychiatry 42:496-504.
SPSS (2002). Statistical package for social studies. Version 13.0. SAS Institute: Cary, NC, USA healthy youths. J Am Acad Child Adolesc Psychiatry 48:299-307.
Tabares-Seisdedos R, Balanza-Martinez V, Sanchez-Moreno J, Selva-Vera, G, Rubio, C, Mata, I, et al
. (2008). Neurocognitive and clinical predictors of functional outcome in patients with schizophrenia and bipolar I disorder at one-year follow-up. J Affect Disord 109:286-299.
JM Thompson, JH Huges, S Watson, JM Gray, IN Ferrier, AH Young (2005). Neurocognitive impairment in euthymic patients with bipolar affective disorder. Br J Psychiatry 186:32-40.
Wechsler D (1987). Wechsler memory scale revised manual. San Antonio, TX: Psychological Corporation, Harcourt Brace L Co. Publishers.
Young AH, Gallagher P, Watson S, Del-Estal D, Owen BM, Ferrier IN (2004). Improvements in neurocognitive function and mood following adjunctive treatment with mifepristone (RU-486) in bipolar disorder. Neuropsychopharmacology 29:1538-1545.
Zubieta JK, Huguelet P, O'Neil RL, Giordani BJ (2001). Cognitive function in bipolar I disorder. Psychiatry Res 102:9-20.
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7]