Neuropsychological deficits and functional impairment in bipolar depression, hypomania and euthymia

OBJECTIVE: To examine whether patients with bipolar disorder (BD) have subtle neuropsychological deficits that manifest clinically as cognitive and functional compromise, and this study attempted to determine the pattern of such cognitive deficits and their functional impact across all three phases of BD. We hypothesised that euthymia does not equate with normal neuropsychological function and that each phase has a characteristic pattern of deficits, with disturbance in attention and memory being common across all phases of the illness: (i) bipolar depression - psychomotor slowing and impairment of memory; (ii) hypomania by frontal-executive deficits and (iii) euthymia - a mild disturbance of attention, memory and executive function. METHODS: Twenty-five patients with a diagnosis of bipolar I disorder underwent neuropsychological testing over a period of 30 months in the natural course of their illness while hypomanic and/or depressed and/or euthymic. The results from these assessments were compared with findings from neuropsychological tests conducted on 25 healthy controls matched for age, sex, education and handedness. RESULTS: Initial analyses revealed modest impairment in executive functioning, memory and attention in both hypomanic and depressed bipolar patients, with additional fine motor skills impairment in the latter. Memory deficits, also noted in euthymic patients, were non-significant after controlling for confounding variables, although bipolar depressed patients remained significantly impaired on tests of verbal recall. Bipolar depressed and hypomanic patients differed with respect to the nature of their memory impairment. Depressed patients were more impaired as compared with euthymic patients on tests of verbal recall and fine motor skills. Psychosocial functioning was impaired across all three patient groups, but only in depressed and hypomanic patients did this correlate significantly with neuropsychological performance. CONCLUSIONS: The mood-state-related cognitive deficits in both bipolar depression and hypomania compromise psychosocial function when patients are unwell. In euthymic patients, subtle impairments in attention and memory suggest that an absence of symptoms does not necessarily equate to 'recovery'. The possibility of persistent cognitive deficits in BD is an issue of profound clinical and research interest that warrants further investigation; however, future research needs to adopt more sophisticated neuropsychological probes that are able to better define state and trait deficits and determine their functional impact.     

RESEARCH: Cognitive Rehabilitation for Bipolar Disorder: An Open Trial for Employed Patients with Residual Depressive Symptoms

Bipolar disorder is characterized by recurrent episodes of depression and/or mania along with interepisodic mood symptoms that interfere with psychosocial functioning. Despite periods of symptomatic recovery, individuals with bipolar disorder often continue to experience impairments in psychosocial functioning, particularly occupational functioning. Two determinants of psychosocial functioning of euthymic (neither fully depressed nor manic) individuals with bipolar disorder are residual depressive symptoms and cognitive impairment (i.e., difficulties with executive functioning, attention, and memory). The present study explored whether a new cognitive remediation (CR) treatment designed to treat residual depressive symptoms and, for the first time to the best of our knowledge, address cognitive impairment would be associated with improvement in psychosocial functioning in individuals with bipolar disorder. Following a neuropsychological and clinical assessment 18 individuals with DSM‐IV bipolar disorder were treated with 14 individual sessions of CR. Results indicated that at the end of treatment, as well as at the 3‐months follow‐up, patients showed lower residual depressive symptoms, and increased occupational, as well as overall psychosocial functioning. Pretreatment neuropsychological impairment predicted treatment response. Improvements in executive functioning were associated with improvements in occupational functioning. These findings suggest that treating residual depressive symptoms and cognitive impairment may be an avenue to improving occupational and overall functioning in individuals with bipolar disorder.     

Evolution of cognitive impairment in bipolar disorder: a systematic review of cross-sectional evidence

OBJECTIVES: The notion that sufferers of bipolar disorder achieve complete syndromal and functional recovery between illness episodes has been brought into question by evidence that a large proportion of patients fail to regain premorbid levels of functioning after the resolution of major affective symptoms. A growing body of evidence suggests that bipolar patients exhibit neuropsychological impairment that persists even during the euthymic state, which may be a contributory factor to poor psychosocial outcome. However, the aetiology of such impairment and its relation to progression of illness are not well understood. This review aims to consider evidence from studies investigating both the relationship between cognitive impairment and clinical outcome and studies of neurocognitive function in unaffected first-degree relatives (FDRs) of bipolar sufferers to address issues of the temporal evolution of cognitive impairment in bipolar disorder. METHODS: Systematic literature review. RESULTS: The weight of evidence suggests that greater neuropsychological dysfunction in bipolar disorder is associated with a worse prior course of illness, particularly the number of manic episodes, hospitalizations and length of illness. The most consistent finding was a negative relationship between the number of manic episodes and verbal declarative memory performance. Impairment in unaffected FDRs was reported in verbal declarative memory and some facets of executive function. CONCLUSIONS: Cognitive impairment may be a trait vulnerability factor for bipolar disorder that is present before illness onset and worsens as the illness progresses. Further investigation into the causal relationship between cognitive impairment and illness course is essential.     

Cognitive impairment in euthymic bipolar patients: implications for clinical and functional outcome

OBJECTIVE: Cognitive impairment in bipolar disorder may be a stable characteristic of the illness, although discrepancies have emerged with regard to what dysfunctions remain during remission periods. The aim of this study was to ascertain whether euthymic bipolar patients would show impairment in verbal learning and memory and in executive functions compared with healthy controls. Secondly, to establish if there was a relationship between clinical data and neuropsychological performance. METHODS: Forty euthymic bipolar patients were compared with 30 healthy controls through a battery of neuropsychological tests assessing estimated premorbid IQ, attention, verbal learning and memory, and frontal executive functioning. The effect of subsyndromal symptomatology was controlled. RESULTS: Remitted bipolar patients performed worse than controls in several measures of memory and executive function, after controlling for the effect of subclinical symptomatology, age and premorbid IQ. Verbal memory impairment was related to global assessment of function scores, as well as to a longer duration of illness, a higher number of manic episodes, and prior psychotic symptoms. CONCLUSIONS: Results provide evidence of neuropsychological impairment in euthymic bipolar patients, after controlling for the effect of subsyndromal depressive symptoms, suggesting verbal memory and executive dysfunctions. Cognitive impairment seems to be related to a worse clinical course and poor functional outcome.     

Meta-analysis of the association between cognitive abilities and everyday functioning in bipolar disorder

Depp CA, Mausbach BT, Harmell AL, Savla GN, Bowie CR, Harvey PD, Patterson TL. Meta‐analysis of the association between cognitive abilities and everyday functioning in bipolar disorder. Bipolar Disord 2012: 14: 217–226. © 2012 The Authors. Journal compilation © 2012 John Wiley & Sons A/S. Objectives: Neurocognitive deficits are common in bipolar disorder and contribute to functional disability. However, the degree to which general and specific cognitive deficits affect everyday functioning in bipolar disorder is unknown. The goal of this meta‐analysis was to examine the magnitude of the effect of specific neurocognitive abilities on everyday functioning in bipolar disorder. Methods: We conducted a comprehensive meta‐analysis of studies that reported associations between performance on objective neuropsychological tasks and everyday functioning among individuals with bipolar disorder. From an initial pool of 486 papers, 22 studies met inclusion criteria, comprising a total of 1344 participants. Correlation coefficients were calculated for 11 cognitive domains and four measurement modalities for functioning. We also examined effect moderators, such as sample age, clinical state, and study design. Results: The mean Pearson correlation between neurocognitive ability and functioning was 0.27, and was significant for all cognitive domains and varied little by cognitive domain. Correlations varied by methods of everyday functioning assessment, being lower for clinician and self‐report than performance‐based tasks and real‐world milestones such as employment. None of the moderator analyses were significant. Conclusions: Overall, the strength of association between cognitive ability and everyday functioning in bipolar disorder is strikingly similar to that seen in schizophrenia, with little evidence for differences across cognitive domains. The strength of association differed to a greater extent according to functional measurement approach.     

The neuropsychology and neuroanatomy of bipolar affective disorder: a critical review

Objectives: To present a comprehensive review of the existing neuropsychological and neuroimaging literature on bipolar affective disorder. This review critically evaluates two common conceptions regarding the neuropsychology of bipolar disorder: 1) that, in contrast to schizophrenia, bipolar affective disorder is not associated with general cognitive impairment independent of illness episodes, and 2) relative right hemisphere (RH) dysfunction is implicated in bipolar illness patients, supported by reports of relatively greater impairment in visuospatial functioning, lateralization abnormalities, and mania secondary to RH lesions.

Methods: The major computerized databases (Medline and PSYCInfo) were consulted in order to conduct a comprehensive, integrated review of the literature on the neuropsychology and neuroanatomy of bipolar disorder. Articles meeting specified criteria were included in this review.

Results: In a critical evaluation of the above notions, this paper determines that: 1) while there is little evidence for selective RH dysfunction, significant cognitive impairment may be present in bipolar illness, particularly in a subgroup of chronic, elderly or multiple‐episode patients, suggesting a possible toxic disease process, and 2) the underlying functional correlate of these cognitive deficits may be white matter lesions (‘signal hyperintensities’) in the frontal lobes and basal ganglia, regions critical for executive function, attention, speeded information processing, learning and memory, and affect regulation. While this hypothesized neural correlate of cognitive impairment in bipolar disorder is speculative, preliminary functional neuroimaging evidence supports the notion of frontal and subcortical hypometabolism in bipolar illness.

Conclusions: The etiology of the structural brain abnormalities commonly seen in bipolar illness, and their corresponding functional deficits, remains unknown. It is possible that neurodevelopmental anomalies may play a role, and it remains to be determined whether there is also some pathophysiological progression that occurs with repeated illness episodes. More research is needed on first‐episode patients, relatives of bipolar probands, and within prospective longitudinal paradigms in order to isolate disease‐specific impairments and genetic markers of neurocognitive function in bipolar disorder.     

Insight in bipolar disorder: associations with cognitive and emotional processing and illness characteristics

van der Werf‐Eldering MJ, van der Meer L, Burger H, Holthausen EAE, Nolen WA, Aleman A. Insight in bipolar disorder: associations with cognitive and emotional processing and illness characteristics.
Bipolar Disord 2011: 13: 343–354. © 2011 The Authors.
Journal compilation © 2011 John Wiley & Sons A/S. Objective: To investigate the multifactorial relationship between illness insight, cognitive and emotional processes, and illness characteristics in bipolar disorder patients. Methods: Data from 85 euthymic or mildly to moderately depressed bipolar disorder patients were evaluated. Insight was measured using the Mood Disorder Insight Scale (total score and subscale scores: awareness of illness, symptom attribution, and need for treatment). Cognitive and emotional functioning was measured in four domains (processing speed, memory, executive functioning, and emotional learning) in addition to premorbid IQ. Illness characteristics were assessed using the Mini‐International Neuropsychiatric Interview, the Questionnaire for Bipolar Disorder, and the Inventory of Depressive Symptomatology‐self rating scale. Regression analyses were performed for the whole sample. Post‐hoc, interactions with lifetime psychotic features (LPF) were statistically tested and if significant, analyses were repeated for patients with (n = 36) and without (n = 49) LPF separately. Results: In the whole group, better insight was associated with lower processing speed, better memory performance, increased emotional learning, higher level of depressive symptoms, and longer duration of illness. Patients with LPF had worse awareness of illness, but better symptom attribution than patients without LPF. No group differences for need for treatment and overall insight were found. Finally, processing speed significantly predicted subscores for symptom attribution in patients with LPF only. Conclusions: Cognitive functioning as well as impairments in emotional learning and psychotic features independently contributes to impaired insight in bipolar disorder. Processing speed seems to be a key variable in the prediction of insight in patients with LPF and not in patients without LPF.     

The impact of neurocognitive impairment on occupational recovery of clinically stable patients with bipolar disorder: a prospective study

Bearden CE, Shih VH, Green MF, Gitlin M, Sokolski KN, Levander E, Marusak S, Hammen C, Sugar CA, Altshuler LL. The impact of neurocognitive impairment on occupational recovery of clinically stable patients with bipolar disorder: a prospective study.
Bipolar Disord 2011: 13: 323–333. © 2011 The Authors.
Journal compilation © 2011 John Wiley & Sons A/S. Objective: Many patients with bipolar disorder do not regain their premorbid level of occupational functioning even after mood episodes have resolved. The reasons for this are not well understood. We evaluated the relationship between neurocognition and occupational function in bipolar disorder patients, following symptomatic recovery. Methods: A total of 79 previously employed adults with bipolar I disorder who achieved symptomatic recovery (i.e., at least six weeks clinically euthymic) following a manic episode underwent a neurocognitive evaluation and assessment of occupational functioning. Study participants were evaluated every three months thereafter for up to nine months. Factor analysis was applied to reduce the initial set of neurocognitive variables to five domains: episodic memory, working memory/attention, executive function, visual scanning, and speed of processing. Multiple logistic regression models were used to examine the joint predictive values of these domains for determining occupational recovery. Results: At the time of symptomatic recovery, four of five neurocognitive factors were significant predictors of concomitant occupational recovery and the fifth, executive function, showed a trend in the same direction. For those not occupationally recovered at baseline, longitudinal analyses revealed that changes between baseline and the three‐month follow‐up timepoint in most cognitive domains were robust and highly significant predictors of occupational recovery at three months. Conclusions: These findings indicate that better neurocognitive function in multiple domains and improvement in these domains over time are strongly predictive of subsequent occupational recovery. Treatments that target cognitive deficit may therefore have potential for improving long‐term vocational functioning in bipolar illness.     

Cognitive function across manic or hypomanic, depressed, and euthymic states in bipolar disorder

OBJECTIVE: The study aims were to address neuropsychological functioning across different states of bipolar illness and to determine relationships among clinical features, neuropsychological performance, and psychosocial functioning. METHOD: Several domains of cognitive function were examined in 30 depressed bipolar patients (DSM-IV criteria for major depression, Hamilton Depression Rating Scale score > or = 17), 34 manic or hypomanic bipolar patients (DSM-IV criteria for manic or hypomanic episode, Young Mania Rating Scale score > or = 12), and 44 euthymic bipolar patients (6 months of remission, Hamilton depression scale score < or = 8, and Young Mania Rating Scale score < or = 6). The comparison group consisted of 30 healthy subjects without history of neurological or psychiatric disorders. A neuropsychological battery assessed executive function, attention, and verbal and visual memory. RESULTS: The three groups showed cognitive dysfunction in verbal memory and frontal executive tasks in relation to the comparison group. Low neuropsychological performance was associated with poor functional outcome. Impairment of verbal memory was related to the duration of illness and the numbers of previous manic episodes, hospitalizations, and suicide attempts. CONCLUSIONS: A poorer performance was observed in all bipolar groups regarding executive function and verbal memory in relation to the healthy comparison subjects. These cognitive difficulties, especially related to verbal memory, may help explain the impairment regarding daily functioning, even during remission. Further studies should focus on testing, whether optimizing prophylactic pharmacological treatment and psychoeducation might reduce cognitive impairment, and whether bipolar patients would benefit from neuropsychological rehabilitation in order to reduce the impact of cognitive impairment in their overall functioning.     

The duration of inpatient admission predicts cognitive functioning at discharge in patients with bipolar disorder

Previous studies of cognitive functioning in bipolar disorder generally indicate that a more severe course of illness is associated with greater cognitive impairment. In particular, a history of greater number and longer duration of mood episodes predicts enduring cognitive deficits in euthymic patients. Shifting the focus of this investigation to the cognitive effects of a discrete mood episode, the current study aimed to explore whether patients who require a longer hospitalization to stabilize from an acute episode of mood disturbance present with more compromised cognitive functioning during the phase of early recovery. For this purpose, the study examined the link between the duration of inpatient admission and neuropsychological test scores at the time of discharge in 41 patients with bipolar disorder. Participants were assigned to long (n = 20) and short (n = 21) stay groups using a median split (M = 12). Results indicated that longer admissions were associated with more severe deficits in executive functioning at discharge after controlling for residual mood symptoms and previous number of psychiatric admissions. Findings from the current study may inform discharge planning for patients with bipolar disorder after an extended hospital stay.     

Neurocognitive impairment in bipolar disorder patients: functional implications

Background: Functional recovery among treated bipolar disorder (BPD) patients is far less likely than syndromal and even symptomatic recovery. We hypothesized that increasingly well‐documented aspects of cognitive impairment may contribute to poor functional outcomes in BPD patients, and reviewed the available research on the topic. Methods: Computerized literature searching identified 12 studies with 13 comparisons that simultaneously evaluated cognitive and functional status in euthymic (n = 8) or non‐euthymic (n = 5 comparisons) adult BPD patients versus otherwise similar healthy controls. Results: In 6/8 studies of euthymic BPD patients and 5/5 studies of non‐euthymic BPD patients, neurocognitive impairment was significantly associated with impaired psychosocial functioning, even after adjusting for residual mood symptoms and relevant demographic and clinical variables. Cognitive status was consistently assessed with standardized, performance‐based neuropsychological tests, but functional status usually was based on subjective self‐appraisals. Approximately 55% of BPD patients were unemployed. Conclusions: Available studies are limited by subjective assessments of functional status rather than objective, performance‐based measures. Nevertheless, they support the hypothesis that enduring aspects of cognitive impairment found even in euthymic BPD patients are associated with inferior functioning. These findings encourage further studies with better assessment methods and greater rehabilitative efforts in BPD patients.     

Neurocognitive impairment and psychosocial functioning in bipolar II disorder

Solé B, Bonnin CM, Torrent C, Balanzá‐Martínez V, Tabarés‐Seisdedos R, Popovic D, Martínez‐Arán A, Vieta E. Neurocognitive impairment and psychosocial functioning in bipolar II disorder. Objective: There is a growing body of evidence on neurocognitive impairment in euthymic bipolar patients, but this issue has been studied mostly in bipolar I disorder, data on bipolar II (BD‐II) are scant and discrepant. The two aims of this study were to ascertain whether strictly defined euthymic BD‐II patients would present neurocognitive disturbances and to evaluate their impact on functional outcome. Method: Forty‐three BD‐II patients and 42 demographically and educationally matched healthy subjects were assessed with a comprehensive neuropsychological test battery and with the Social and Occupational Functioning Assessment Scale (SOFAS). The euthymia criteria were reduced (Hamilton Rating Scale for Depression score ≤6 and a Young Mania Rating Scale score ≤6) to minimize the influence of subdepressive symptomatology on cognition and functioning. Results: BD‐II patients showed a significantly lower performance on several measures of attention, learning and verbal memory, and executive function compared with healthy controls. The presence of subthreshold depressive symptomatology and one measure related to executive function (Trail Making Test, part B) was the variables that best predicted psychosocial functioning measured with the SOFAS. Conclusion: This report provides further evidence that euthymic BD‐II patients present cognitive impairment which may impact psychosocial functioning.     

Neuropsychological profile in bipolar disorder: a preliminary study of monotherapy lithium-treated euthymic bipolar patients evaluated at a 2-year interval

Objective: To investigate the cognitive impairment of a sample of euthymic bipolar patients treated with lithium monotherapy at baseline in a 2‐year longitudinal study. Method: Fifteen DSM‐IV‐TR bipolar out‐patients and 15 healthy‐matched controls were cognitively assessed twice over a 2‐year follow‐up. All patients underwent lithium monotherapy on the first evaluation, and they were euthymic in both evaluations. Cognitive assessment was performed by means of a neuropsychological test battery tapping into the main cognitive domains (executive function, attention, processing speed, verbal memory and visual memory). Results: Repeated measures multivariate analysis of variance showed that the bipolar disorder group was cognitively impaired in the executive domain, attention and processing speed, and such deficits were maintained over time. Conclusion: Our results showed that executive dysfunction is the main long‐term neuropsychological deficit of bipolar disorder. Also, the persistence of these deficits did not seem to be influenced by any clinical or pharmacological variables.     

A 15-year prospective follow-up of bipolar affective disorders: comparisons with unipolar nonpsychotic depression

Goldberg JF, Harrow M. A 15‐year prospective follow‐up of bipolar affective disorders: comparisons with unipolar nonpsychotic depression.
Bipolar Disord 2011: 13: 155–163. © 2011 The Authors.
Journal compilation © 2011 John Wiley & Sons A/S. Objectives: Outcome studies have previously documented substantial functional disability among individuals with bipolar disorder, although few follow‐up studies have examined the prospective course of illness beyond 10 years’ duration. Methods: A total of 95 patients with mood disorders (46 with bipolar I disorder and 49 with unipolar nonpsychotic depression) were assessed 15 years after index hospitalization. Logistic and linear regression models were used to identify predictors of global functioning, work disability, and social adjustment. Results: At 15‐year follow‐up, good overall functioning was significantly less common among subjects with bipolar disorder (35%) than unipolar depression (73%) (p < 0.001). Work disability was significantly more extensive in bipolar than unipolar disorder subjects (p < 0.001). Logistic regression indicated that good outcome 15 years after index hospitalization was significantly predicted by a unipolar rather than bipolar disorder diagnosis and the absence of a depressive episode in the preceding year. Past‐year depressive, but not past‐year manic, syndromes were associated with poorer global outcome and greater work disability. In addition, subsyndromal depression was significantly associated with poorer global, work, and social outcome among bipolar, but not unipolar disorder subjects. Conclusions: A majority of individuals with bipolar I disorder manifest problems with work and global functioning 15 years after an index hospitalized manic episode Recurrent syndromal and subsyndromal depression disrupts multiple domains of functional outcome more profoundly in bipolar than unipolar mood disorders. The prevalence, and correlates, of impaired long‐term outcome parallel those reported in shorter‐term functional outcome studies of bipolar disorder.     

Neurocognitive function in unmedicated manic and medicated euthymic pediatric bipolar patients

OBJECTIVE: A systematic evaluation of neuropsychological functioning in individuals with pediatric bipolar disorder is necessary to clarify the types of cognitive deficits that are associated with acutely ill and euthymic phases of the disorder and the effects of medication on these deficits. METHOD: Unmedicated (N=28) and medicated (N=28) pediatric bipolar patients and healthy individuals (N=28) (mean age=11.74 years, SD=2.99) completed cognitive testing. Groups were matched on age, sex, race, parental socioeconomic status, general intelligence, and single-word reading ability. A computerized neurocognitive battery and standardized neuropsychological tests were administered to assess attention, executive function, working memory, verbal memory, visual memory, visuospatial perception, and motor skills. RESULTS: Subjects with pediatric bipolar disorder, regardless of medication and illness status, showed impairments in the domains of attention, executive functioning, working memory, and verbal learning compared to healthy individuals. Also, bipolar subjects with comorbid attention deficit hyperactivity disorder (ADHD) performed worse on tasks assessing attention and executive function than patients with bipolar disorder alone. CONCLUSIONS: The absence of differences in the deficits of neurocognitive profiles between acutely ill unmedicated patients and euthymic medicated patients suggests that these impairments are trait-like characteristics of pediatric bipolar disorder. The cognitive deficits found in individuals with pediatric bipolar disorder suggest significant involvement of frontal lobe systems supporting working memory and mesial temporal lobe systems supporting verbal memory, regardless of ADHD comorbidity.     

Cognitive impairment in schizoaffective disorder: a comparison with non-psychotic bipolar and healthy subjects

Objective: Only a few studies have examined specifically the neuropsychological performance of schizoaffective patients. Method: The sample consisted of 34 euthymic DSM‐IV schizoaffective patients, who were compared with 41 euthymic bipolar patients without history of psychotic symptoms and 35 healthy controls. Euthymia was defined by a score of 6 or less at the Young Mania Rating Scale and a score of 8 or less at the Hamilton Depression Rating Scale for at least 6 months. Patients were compared with several clinical, occupational, and neuropsychological variables such as executive function, attention, verbal and visual memory and the two groups were contrasted with 35 healthy controls on cognitive performance. The three groups were compared using mancova after checking the potential role of several co‐variables. Results: Schizoaffective patients showed greater impairment than controls and bipolar patients, in several domains, including verbal memory, executive function, and attentional measures. Bipolar patients without history of psychosis performed similar to the controls except for verbal fluency. Conclusion: Schizoaffective disorder carries more neurocognitive impairment than non‐psychotic bipolar disorder and more occupational difficulties.     

Association of clinical symptoms and neurocognitive performance in bipolar disorder: a longitudinal study

Chaves OC, Lombardo LE, Bearden CE, Woolsey MD, Martinez DM, Barrett JA, Miller AL, Velligan DI, Glahn DC. Association of clinical symptoms and neurocognitive performance in bipolar disorder: a longitudinal study.
Bipolar Disord 2011: 13: 118–123. © 2011 The Authors. Journal compilation © 2011 John Wiley & Sons A/S. Objective: Despite evidence that individuals with bipolar disorder have neurocognitive impairment that persists during euthymia, the impact of changes in affective symptoms on cognitive function has not been well established. Here, we sought to determine whether specific neurocognitive functions are sensitive to mood changes in individuals with bipolar disorder assessed three months apart without changes in treatment regimen. Methods: A total of 29 individuals with DSM‐IV bipolar disorder and 30 healthy controls participated in the study. All participants received a comprehensive neuropsychological assessment and ratings of depressive [Hamilton Depression Rating Scale (HAMD)] and manic [Young Mania Rating Scale (YMRS)] symptoms at baseline and follow‐up. Changes in symptoms over time were calculated and were examined in relation to changes in neurocognitive performance. Results: At baseline, clinically stable but symptomatic patients were impaired on measures of speed of processing and attention. Over the three‐month follow‐up period, HAMD scores changed by 6 points on average [range: ?10 to +18] and YMRS scores changed by 5.31 points on average [range ?11 to +15]. Changes in depressive symptoms were correlated with poorer verbal fluency, while no relationship between manic symptoms and neuropsychological performance was detected. Conclusions: Individuals with bipolar disorder showed consistent impairment on speed of processing and attention over time, despite significant changes in mood.     

Neurocognitive functions in euthymic bipolar patients

Objective: Meta‐analytic findings support the hypothesis of specific neurocognitive deficits for bipolar patients in the domains of attention, processing speed, memory and executive functions. This study aims to show neurocognitive impairment in euthymic patients with bipolar I disorder compared with healthy controls while detailing the impact of medication side‐effects or illness characteristics on neuropsychological test performance. Method: Forty euthymic patients with bipolar I disorder were compared with 40 healthy controls in a cross‐sectional design. Clinical features and neuropsychological measures of IQ, psychomotor speed, verbal fluency, learning and memory, executive functions and attention were assessed. Results: Patients without antipsychotic drug use did not differ significantly from healthy controls in any neuropsychological measure. Yet patients treated with antipsychotics showed significant underperformance in the domains of semantic fluency, verbal learning and recognition memory as well as executive functions related to planning abilities, even when clinical features were controlled for. Conclusion: The impact of antipsychotic medication needs to be further clarified for euthymic bipolar patients and should be considered when neuropsychological test performance is interpreted.     

Neuropsychological functioning in euthymic bipolar disorder: a meta-analysis

OBJECTIVE: Although cognitive deficits are prominent in symptomatic patients with bipolar disorder, the extent and pattern of cognitive impairment in euthymic patients remain uncertain. METHOD: Neuropsychological studies comparing euthymic bipolar patients and healthy controls were evaluated. Across studies, effect sizes reflecting patient-control differences in task performance were computed for the 15 most frequently studied cognitive measures in the literature. RESULTS: Across the broad cognitive domains of attention/processing speed, episodic memory, and executive functioning, medium-to-large performance effect size differences were consistently observed between patients and controls, favoring the latter. Deficits were not observed on measures of vocabulary and premorbid IQ. CONCLUSION: Meta-analytic findings provide evidence of a trait-related neuropsychological deficit in bipolar disorder involving attention/processing speed, memory, and executive function. Findings are discussed with regard to potential moderators, etiologic considerations, limitations, and future directions in neuropsychological research on bipolar disorder.     

Cognitive functioning in elderly patients with early onset bipolar disorder

BACKGROUND: Very little is known about the long term cognitive sequelae of bipolar disorder. AIM: To investigate neuropsychological functioning in older euthymic persons with early onset bipolar disorder. METHOD: Fifteen older patients (age >60) with an early onset (<50 years) bipolar-I disorder in a euthymic mood were tested using a comprehensive neuropsychological test battery. Neuropsychological functioning was compared with that of a sex, age and education-matched group of 15 comparison subjects without mood disorders or memory complaints. RESULTS: Bipolar subjects scored lower than comparison subjects on selective attention, verbal memory, verbal fluency and mental effort tests. CONCLUSIONS: The findings suggest that euthymic bipolar patients are impaired across a range of cognitive domains. This could represent a trait-like cognitive disability related to the disease, as the impairments are comparable with those found in younger bipolar patients.