Neuropsychological performance in depressed and euthymic bipolar patients

Cognitive reserve and cognition in mood disorders: A systematic review and meta-analysis

Cognitive functioning heterogeneity is a well-recognized phenomenon in individuals diagnosed with mood disorders. Cognitive Reserve (CR) has been linked to multiple positive outcomes, including cognitive performance in these patients. This systematic review and meta-analysis aim to provide a comprehensive analysis of the relationship between CR and cognitive functioning in individuals with mood disorders, including bipolar disorder and depressive disorders. Following PRISMA guidelines, a systematic review and meta-analysis was conducted of original research exploring the relationship between CR and cognitive performance in adult individuals with mood disorders. The literature search was conducted on PubMed, Scopus, and Web of Science, from 2002 to September 2023, and the Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of studies. Overall, 17 studies met the inclusion criteria for the systematic review and 11 for the meta-analysis. Both qualitative and quantitative findings suggested a positive relationship between CR measures and cognitive domains. CR emerges as a possible protective factor for cognitive functioning in adult individuals with mood disorders, potentially helping to mitigate the cognitive impairments associated with the disorder. These findings underscore the importance of the fact that promoting and enhancing CR could help in the cognitive prognosis of this population.

Clinical neuropsychological characteristics of bipolar disorder, with a focus on cognitive and linguistic pattern: a conceptual analysis

Neuropsychology is an academic discipline that investigates the intricate interplay between the brain, mind, and behavior. It accomplishes this by examining the underlying structure and activities of the brain, with a particular focus on psychological phenomena such as language, motivation, memory, attention, thinking, consciousness, learning, and efficacy. The assessment of neuropsychological changes in individuals diagnosed with bipolar disorder has received limited attention in comparison to other psychiatric conditions, such as schizophrenia, for instance. Nevertheless, there has been a growing interest in the etiological implications, therapies, preventions, and prognostic factors related to social competence and the quality of life of patients. The objective of this review is to compile and analyze the existing research conducted thus far on the association between cognitive abnormalities and bipolar disorder. This study has examined research conducted across many stages of the condition, including depression and mania. Additionally, it has explored comparative studies involving people with schizophrenia, as well as the potential impact of psychopharmaceutical interventions.

A scoping review of near infrared spectroscopy studies employing a verbal fluency task in bipolar disorder

BACKGROUND

Deficits in cognitive functioning, including attention, memory, and executive functions, along with impairments in language production, are present in patients with bipolar disorder (BD) patients during mood phases, but also during euthymia.Verbal fluency tasks (VFTs), being able to evaluate integrity of a wide range of cognitive domains and represent, can be used to screen for these disturbances. Neuroimaging studies, including Near-InfraRed Spectroscopy (NIRS), have repeatedly showed widespread alterations in the prefrontal and temporal cortex during the performance of VFTs in BD patients. This review aims to summarize the results of NIRS studies that evaluated hemodynamic responses associated with the VFTs in prefrontal and temporal regions in BD patients.

METHODS

We performed a scoping review of studies evaluating VFT-induced activation in prefrontal and temporal regions in BD patients, and the relationship between NIRS data and various clinical variables.

RESULTS

15 studies met the inclusion criteria. In BD patients, compared to healthy controls, NIRS studies showed hypoactivation of the dorsolateral prefrontal cortex, ventrolateral prefrontal cortex and anterior temporal regions. Moreover, clinical variables, such as depressive and social adaptation scores, were negatively correlated with hemodynamic responses in prefrontal and temporal regions, while a positive correlation were reported for measures of manic symptoms and impulsivity.

LIMITATIONS

The heterogeneity of the studies in terms of methodology, study design and clinical characteristics of the samples limited the comparability of the findings.

CONCLUSIONS

Given its non-invasiveness, good time-resolution and no need of posturalconstraint, NIRS technique could represent a useful tool for the evaluation of prefrontal and temporal haemodynamic correlates of cognitive performances in BD patients.

Impulsivity, personality and bipolar disorder

Background

Increased impulsivity is a diagnostic feature of mania in bipolar disorder (BD). However it is unclear whether increased impulsivity is also a trait feature of BD and therefore present in remission. Trait impulsivity can also be construed as a personality dimension but the relationship between personality and impulsivity in BD has not been explored. The aim of this study was to examine the relationship of impulsivity to clinical status and personality characteristics in patients with BD.

Methods

We measured impulsivity using the Barratt Impulsiveness Scale (BIS-11) and personality dimensions using Eysenck Personality Questionnaire in 106 BD patients and demographically matched healthy volunteers. Clinical symptoms were assessed in all participants using the Clinical Global Impressions Scale, the Montgomery-Asberg Depression Rating Scale and the Young Mania Rating Scale. Based on their clinical status patients were divided in remitted (n = 36), subsyndromal (n = 25) and syndromal (n = 45).

Results

There was no difference in BIS-11 and EPQ scores between remitted patients and healthy subjects. Impulsivity, Neuroticism and Psychoticism scores were increased in subsyndromal and syndromal patients. Within the BD group, total BIS-11 score was predicted mainly by symptoms severity followed by Psychoticism and Neuroticism scores.

Conclusions

Increased impulsivity may not be a trait feature of BD. Symptom severity is the most significant determinant of impulsivity measures even in subsyndromal patients.

Reliability and Validity of THINC-it in Evaluating Cognitive Function of Patients with Bipolar Depression

PURPOSE

The THINC-integrated tool (THINC-it) as a brief screening tool can assesses cognitive impairment in patients with major depressive depression (MDD). Here, we aim to evaluate the reliability and validity of the THINC-it in a bipolar depression (BD-D) group in comparison with a healthy control (HC) group.

MATERIALS AND METHODS

Both groups were matched according to age, gender, years of education, and IQ. All participants completed the THINC-it test, including Spotter, Symbol Check, Codebreaker, Trails, and the Perceived Deficits Questionnaire for Depression-5-item (PDQ-5-D). The concurrent validity and internal consistency of the THINC-it test were analyzed, and 30 healthy controls were randomly sampled to retest THINC-it to verify the reliability of the THINC-it retest. The correlation between THINC-it and Hamilton Depression Scale (HAMD-17) and Sheehan Disability Scale (SDS) was also analyzed.

RESULTS

Fifty-eight patients with BD-D and 61 HCs were included for final analysis. There were significant mean difference (MD) standard errors (SE) between two groups in PDQ-5-D, Spotter and Codebreaker (all P<0.01), Trails (P=0.015). There was no significant difference in Symbol Check (MD (SE)=-0.01 (0.18), P=0.938; 95% CI=-0.38 to 0.35). The Cronbach's α of PDQ-5-D was 0.640. The intraclass correlation coefficient (ICC) was between 0.440 and 0.757. The highest concurrent validity was PDQ-5-D (r=0.812, P<0.001). PDQ-5-D was positively correlated with HAMD-17 and SDS score (P<0.01). The objective test had no significant correlation with HAMD-17 and SDS scores (P>0.05).

CONCLUSION

This study found that THINC-it can accurately present the cognitive impairment of patients with BD-D. It can be potentially applied in assessing the cognitive function of patients with BD-D although Symbol Check may not accurately reflect the level of cognitive function. The concurrent validity and retest reliability are lower than expected, we need to further increase the sample size to study.

Functional outcome assessment in bipolar disorder: A systematic literature review

OBJECTIVES

Functional impairment is an important driver of disability in patients with bipolar disorder (BD) and can persist even when symptomatic remission has been achieved. The objectives of this systematic literature review were to identify studies that assessed functioning in patients with BD and describe the functional scales used and their implementation.

METHODS

A systematic literature review of English-language articles published between 2000 and 2017 reporting peer-reviewed, original research related to functional assessment in patients with BD was conducted.

RESULTS

A total of 40 articles met inclusion criteria. Twenty-four different functional scales were identified, including 13 clinician-rated scales, 7 self-reported scales, and 4 indices based on residential and vocational data. The Global Assessment of Functioning (GAF) and the Functional Assessment Short Test (FAST) were the most commonly used global and domain-specific scales, respectively. All other scales were used in ≤2 studies. Most studies used ≥1 domain-specific scale. The most common applications of functional scales in these studies were evaluations of the relationships between global or domain-specific psychosocial functioning and cognitive functioning (eg, executive function, attention, language, learning, memory) or clinical variables (eg, symptoms, duration of illness, number of hospitalizations, number of episodes).

CONCLUSIONS

The results of this review show growing interest in the assessment of functioning in patients with BD, with an emphasis on specific domains such as work/educational, social, family, and cognitive functioning and high utilization of the GAF and FAST scales in published literature.

Methylene blue treatment for residual symptoms of bipolar disorder: randomised crossover study

BACKGROUND

Residual symptoms and cognitive impairment are among important sources of disability in patients with bipolar disorder. Methylene blue could improve such symptoms because of its potential neuroprotective effects.

AIMS

We conducted a double-blind crossover study of a low dose (15 mg, 'placebo') and an active dose (195 mg) of methylene blue in patients with bipolar disorder treated with lamotrigine.

METHOD

Thirty-seven participants were enrolled in a 6-month trial (trial registration: NCT00214877). The outcome measures included severity of depression, mania and anxiety, and cognitive functioning.

RESULTS

The active dose of methylene blue significantly improved symptoms of depression both on the Montgomery-Åsberg Depression Rating Scale and Hamilton Rating Scale for Depression (P = 0.02 and 0.05 in last-observation-carried-forward analysis). It also reduced the symptoms of anxiety measured by the Hamilton Rating Scale for Anxiety (P = 0.02). The symptoms of mania remained low and stable throughout the study. The effects of methylene blue on cognitive symptoms were not significant. The medication was well tolerated with transient and mild side-effects.

CONCLUSIONS

Methylene blue used as an adjunctive medication improved residual symptoms of depression and anxiety in patients with bipolar disorder.

Low compliance to pharmacological treatment is linked to cognitive impairment in euthymic phase of bipolar disorder

BACKGROUND

Cognitive impairment and low compliance to pharmacological treatment are frequent complications in bipolar disorder. Moreover, low compliance in patients with bipolar disorder is one of the main reasons for relapse. This in turn, is associated with an increase in neurocognitive symptoms. The current study aimed to determine whether attention, memory, and executive function are related to the level of compliance to pharmacological treatment in individuals with bipolar disorder in euthymic phase.

METHOD

We examined 34 patients with bipolar disorder (12 with low compliance to the treatment and 22 with high compliance to the treatment) according to the DSM-IV criteria, in the range of 18-55 years. All patients were assessed through a neuropsychological battery in one single session. Analysis of covariance (ANCOVA) was used to compare neuropsychological test scores between low and high compliance patients. Clinical and sociodemographic characteristics were included as covariates in the study.

RESULTS

Patients with low level of compliance performed significantly worse than high treatment compliance on verbal memory immediate free recall (F (1)=12.14, p=.002), verbal memory immediate cued recall (F (1)=10.45, p=.003), verbal memory delayed free recall (F (1)=5.52, p=.027), and verbal memory delayed cued recall (F (1)=6.11, p=.021). Covariates such as number of manic episodes, history of psychosis and years of education were found significant for executive functions and processing speed.

CONCLUSION

We found that low compliance to pharmacological treatment is consistently linked to immediate and delayed verbal memory. In addition, executive function and processing speed were associated with clinical and demographic characteristics. Limitations of this study include the small sample size, a cross-sectional design that cannot address causality, and inability to account for pharmacologic effects.

A review on the impact of cognitive dysfunction on social, occupational, and general functional outcomes in bipolar disorder

OBJECTIVES

Bipolar disorder (BD) is associated with significant impairment in cognitive performance across multiple domains of function that often persist after clinical recovery. It remains unclear, however, as to whether this process is related to the clinical status of BD being depressed, manic/hypomanic, or euthymic. In this review, we examine the literature on the cross-sectional and longitudinal relationships between cognitive function and general function depending on the clinical phase of BD.

METHODS

A systematic review of original research that studied both cognitive function and general function in adults (18-60 years), restricted to BD, was conducted in a total of 18 studies meeting inclusion/exclusion criteria.

RESULTS

Results show cross-sectional and prospective relationships between cognitive function and general function in patients with BD in both symptomatic and euthymic patients with BD. While studies using general measures of function (e.g., Global Assessment of Function scale) show more inconsistent associations with cognitive function, those employing assessments of domain specific function, suggest a consistent relationship between social and occupational function and cognitive performance. Executive function is commonly affected by cognitive deficits in these patients, but in addition a variety of domains show associations with functional outcomes (e.g., social function, occupational function). Notably, the emerging evidence suggests that cognitive function may be a better predictor of future general function than affective symptom severity.

CONCLUSIONS

Despite some inconsistencies, in sum the literature on the relationship between cognitive function and general function in BD implicates both cross-sectional and longitudinal associations, both in symptomatic and euthymic patients with BD. And in terms of capturing these changes functional scales in particular domain-specific measures seem superior to general measures.

The Relationship Between Educational Years and Phonemic Verbal Fluency (PVF) and Semantic Verbal Fluency (SVF) Tasks in Spanish Patients Diagnosed With Schizophrenia, Bipolar Disorder, and Psychotic Bipolar Disorder

Semantic and verbal fluency tasks are widely used as a measure of frontal capacities. It has been well described in literature that patients affected by schizophrenic and bipolar disorders present a worse execution in these tasks. Some authors have also noted the importance of educational years. Our objective is to analyze whether the effect of cognitive malfunction caused by apathology is superior to the expected effect of years of education in phonemic verbal fluency (PVF) and semantic verbal fluency (SVF) task execution. A total of 62 individuals took part in this study, out of which 23 were patients with schizophrenic paranoid disorder, 11 suffered from bipolar disorder with psychotic symptomatology, 13 suffered from bipolar disorder without psychotic symptomatology, and 15 participants were nonpathological individuals. All participants were evaluated with the PVF and SVF tests (animals and tools). The performance/execution results were analyzed with a mixed-model ANCOVA, with educational years as a covariable. The effect of education seems to be more determined by PVF FAS tests than by SVF. With PVF FAS tasks, the expected effect of pathology disappears when the covariable EDUCATION is introduced. With SVF tasks, the effect continues to be significant, even though the EDUACTION covariable dims such effect. These results suggest that SVF tests (animals category) are better evaluation tools as they are less dependent on the patients' education than PVF FAS tests.

Left temporal activation associated with depression severity during a verbal fluency task in patients with bipolar disorder: a multichannel near-infrared spectroscopy study

BACKGROUND

Neuroimaging studies using multichannel near-infrared spectroscopy (NIRS) have provided compelling evidence about the dysfunction of the frontotemporal cortices in patients with bipolar disorder (BD). However, it remains unclear whether the dysfunction is associated with mood state or symptom severity. Using NIRS, we aimed to clarify differences in oxygenated hemoglobin (oxy-Hb) activation between depressive and euthymic states as well as regional brain dysfunction in relation to symptom severity in BD.

METHODS

Fifty-five patients with BD, including 30 with bipolar depression (BPD) and 25 with euthymic bipolar disorder (BPE), and 28 healthy controls (HCs) participated in the study. Regional hemodynamic changes during a verbal fluency task (VFT) were monitored using a 52-channel NIRS apparatus.

RESULTS

The mean oxy-Hb changes induced by VFT were significantly smaller in the BD patients than in the HCs in 18 channels in the frontotemporal regions (false-discovery rate p<0.05, p=0.000-0.011). The BPD group exhibited significantly smaller changes in mean oxy-Hb compared with the BPE group in three channels of the left temporal region (p=0.005-0.014). In the BD patients, significant negative correlations were observed between mean oxy-Hb changes in the left temporal regions and the severity of depression.

LIMITATIONS

Our sample size was small, making the results susceptible to type II errors.

CONCLUSIONS

BD patients have persistent hypofunction of the frontotemporal cortical regions. Moreover, the hemodynamic response in the left temporal regions is associated with symptom severity.

Neurocognitive function as a possible marker for remission from clinical high risk for psychosis

BACKGROUND

Recent studies revealed that nonconverters at clinical high risk (CHR) for psychosis comprise those who later remit from initial CHR state and those who do not remit and continue to have attenuated positive symptoms. CHR subjects who remit symptomatically are comparable to healthy controls for both baseline and longitudinal symptoms. However, the neurocognitive characteristics of this population are still obscure.

METHODS

Seventy-five CHR subjects and 61 healthy controls were recruited, and their neurocognitive functions were assessed. CHR subjects were divided into converter, remitter, and non-remitter groups according to their clinical state during a 12 to 24month follow-up.

RESULTS

Only the remitter group was comparable to healthy controls in terms of baseline neurocognitive functions. We observed that remitters showed better performance at baseline on tasks of attention, immediate/delayed verbal memory, verbal fluency, and immediate visual memory compared with converters. Moreover, we found that performance on semantic fluency was significantly improved in remitters but declined in non-remitters over the 2-year follow-up; however, there was no significant difference between these two groups at baseline.

CONCLUSION

CHR nonconverters who later remit from an initial prodromal state do not show reduced neurocognitive functioning compared with healthy controls at baseline. Therefore, an advanced research diagnostic criterion for a CHR state that considers neurocognitive functions is needed to more precisely predict which patients will develop psychosis.

Psychosocial functioning is correlated with activation in the anterior cingulate cortex and left lateral prefrontal cortex during a verbal fluency task in euthymic bipolar disorder: a preliminary fMRI study

AIM

Cognitive impairment may account for functional and occupational disability in patients with bipolar disorder even during periods of euthymia. While imaging suggests structural, neurochemical, and functional abnormalities in bipolar disorder patients, the pathophysiology of these deficits has not been elucidated. It was hypothesized that euthymic bipolar patients would have different cortical activation during a verbal fluency task compared to healthy controls, and that psychosocial functioning would be associated with prefrontal cortical activation during the task in the bipolar group.

METHODS

Ten euthymic bipolar patients and 10 healthy control participants (matched for age, gender, and years of education) underwent functional magnetic resonance imaging (fMRI) during a verbal fluency task, tapping task and visual task. Correlational analysis between the fMRI brain activation and clinical variables of the participants, including Global Assessment of Functioning (GAF) score, was performed.

RESULTS

Compared to the controls, euthymic bipolar patients had significantly greater activation in the bilateral precuneus with similar behavioral performance during the verbal fluency task. There were no significant differences between the groups for the visual task or the simple motor task. Activation in both the left anterior cingulate cortex (ACC) and the left dorsolateral prefrontal cortex (PFC) were significantly positively correlated with GAF score in the euthymic bipolar patients.

CONCLUSION

Both the ACC and lateral PFC regions are components of a neural network that plays a critical role in psychosocial functioning, and are often found to be affected in bipolar patients.

Cognitive compromise in bipolar disorder with chronic cannabis use: cause or consequence?

This article briefly reviews the neuropsychological deficits associated with bipolar disorder and examines how substance abuse, in particular chronic cannabis use, may contribute to these. The focus of the article is cannabis, owing to its popularity in patients with bipolar disorder, although many studies focus on its use in conjunction with other substances. The findings are contextualized within bipolar disorder, examining functional outcome.

Plasma brain-derived neurotrophic factor levels, learning capacity and cognition in patients with first episode psychosis

BACKGROUND

Cognitive impairments are seen in first psychotic episode (FEP) patients. The neurobiological underpinnings that might underlie these changes remain unknown. The aim of this study is to investigate whether Brain Derived Neurotrophic Factor (BDNF) levels are associated with cognitive impairment in FEP patients compared with healthy controls.

METHODS

45 FEP patients and 45 healthy controls matched by age, gender and educational level were selected from the Basque Country area of Spain. Plasma BDNF levels were assessed in healthy controls and in patients. A battery of cognitive tests was applied to both groups, with the patients being assessed at 6 months after the acute episode and only in those with a clinical response to treatment.

RESULTS

Plasma BDNF levels were altered in patients compared with the control group. In FEP patients, we observed a positive association between BDNF levels at six months and five cognitive domains (learning ability, immediate and delayed memory, abstract thinking and processing speed) which persisted after controlling for medications prescribed, drug use, intelligence quotient (IQ) and negative symptoms. In the healthy control group, BDNF levels were not associated with cognitive test scores.

CONCLUSION

Our results suggest that BDNF is associated with the cognitive impairment seen after a FEP. Further investigations of the role of this neurotrophin in the symptoms associated with psychosis onset are warranted.

Stigma experiences in bipolar patients: the impact upon functioning

The aim of this study was to investigate the impact of self-rated stigma and functioning in patients with bipolar disorder in South Brazil. This is a cross-sectional study. Sixty participants with bipolar disorder were recruited from an outpatient Bipolar Disorder Program. Experiences with and impact of perceived stigma were evaluated using the Inventory of Stigmatizing Experiences. Functional impairment was assessed with the Functioning Assessment Short Test (FAST). Higher scores of self-perceived stigma were correlated with higher FAST scores, indicating more disability. After linear correlation analysis, current depressive symptoms, age at onset of treatment, age at diagnosis and functioning were correlated with self-perceived stigma. The study demonstrated a correlation between stigma and poor functioning in bipolar disorder. Perceived stigma is really important to individuals with bipolar disorder, both to how they experience their illness and to its results on functioning. Potential consequences of such results for mental health care professionals are discussed. Differential clinical features, sociocultural factors and the sample size limit the generalization of the present findings.

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.

Neurocognitive impairment across the bipolar spectrum

Bipolar disorder is a severe mental illness that affects nearly 4.4% of the general population when bipolar spectrum disorders are taken into account. Neurocognitive impairment is thought to be a core deficit of this illness since it is present during euthymia. In fact, 40-60% of euthymic patients present with neurocognitive disturbances. Not only the clinical factors but also disturbances in neurocognition can influence the functional outcome of BD patients. Hence, further research is needed in order to clarify the relationship between these variables. Despite the growing body of evidence that has emerged during the last decade, no unique neurocognitive profile has been proposed yet for either BD subtype. The majority of the studies recluted heterogeneous samples (including both bipolar I and II) or focused on BD-I patients only. The aim of this review is to give an overall picture of the main neurocognitive disturbances found in the bipolar spectrum and particularly in BD-II, where the findings are more ambiguous. An extensive review of all the literature has been done regarding this subtype (from 1980 until July 2009). Data available until now suggest that deficits are present across the bipolar spectrum (BD-I and BD-II), but they seem slightly more severe in BD-I. The extent to which either subtype share-or not-some similarities is still unknown. More studies are required but it would also be interesting to reach a consensus in the neuropsychological assessment of BD to facilitate comparisons between the different studies.

Social disability in schizophrenic, schizoaffective and affective disorders 15 years after first admission

BACKGROUND

Interest in social functioning of people suffering from mental illnesses has been increasing over the last few years. Only few studies have investigated differences in social functioning in affective, schizoaffective and schizophrenic patients in the long-term and in a comparative approach.

METHOD

The present study is part of a 15 year follow-up study on patients suffering from severe mental illness. The here reported findings refer to the data of a sample of 177 patients with life-time diagnoses belonging to the schizophrenic, schizoaffective or affective spectrum according to the ICD-10 criteria. Psychopathological, socio-demographic and other illness-related variables were assessed at the index hospitalisation and at the 15 year follow-up evaluation by using the assessment system published by the Association for Methodology and Documentation in Psychiatry (AMDP-system). Information about patients' social disability was assessed by using a modified and further developed version of the WHO disability assessment scale, the (Mannheim) Disability Assessment Schedule (DAS-M scale). Prevalence rates of social disability and differences in the severity of social disability between different groups of mental illnesses were evaluated. And the association between social disability, diagnoses and psychopathology was analysed.

RESULTS

Compared to affective and schizoaffective patients, schizophrenic patients showed significantly higher levels of social disability in almost all domains. Severe to very severe levels of disability were found in 64% of schizophrenic patients and only in 19% of schizoaffective patients and 5% of affective patients. However, on a descriptive level all three diagnostic groups presented with similar maxima and minima in their profiles of social disability. Multiple regression analyses revealed that the apathy syndrome had the highest impact on the presence of severe social disability with all other psychopathological syndromes, gender, age and diagnosis having no statistically significant influence.

CONCLUSION

Findings indicate that patients' disabilities in different diagnostic groups seem to be of a similar quality and nature despite differences in their severity. The impact of psychopathology on disability seems to be more important than the one of diagnosis per se.

Neuropsychological functioning in health and mood disorder: Modulation by glucocorticoids and their receptors

Numerous studies have shown that disturbances in hypothalamic-pituitary-adrenal (HPA) axis function and consequent hypercortisolaemia occur in a significant proportion of patients with mood disorders. This dysfunction has been proposed to be an exacerbating factor of depressive symptoms and may predict symptomatic relapse. Glucocorticoids are also known to have a specific role in learning and memory processes. In this review we present a brief overview of the relationship between HPA axis dysfunction and neuropsychological impairment in mood disorders and the specific links between glucocorticoids and cognition in health and illness states. Finally we examine the neuropsychological effects of drugs that specifically target glucocorticoid receptor function.

Resting prefrontal hypometabolism and paralimbic hypermetabolism related to verbal recall deficits in euthymic older adults with bipolar disorder

OBJECTIVES

To evaluate deficits of delayed free recall in euthymic older patients with bipolar disorder and relate deficits to resting cerebral metabolism.

DESIGN

Two group, between subjects.

SETTING

Outpatient.

PARTICIPANTS

Participants included 16 older adult (mean age, 58.7 years; SD = 7.5) euthymic outpatients with bipolar disorder (10 Type I and 6 Type II) and 11 healthy comparison subjects (mean age, 58.3 years; SD = 5.2).

MEASUREMENTS

All participants received resting positron emission tomography with (18)flurodeoxyglucose and, within 10 days, delayed free verbal recall testing with the California Verbal Learning Test II.

RESULTS

Patients with bipolar disorder, relative to healthy comparison subjects, had significantly poorer delayed free verbal recall. In patients with bipolar disorder, relative to healthy comparison subjects, prefrontal hypometabolism (dorsolateral prefrontal cortex) and paralimbic hypermetabolism (hippocampus, parahippocampal gyrus, and superior temporal gyrus) was associated with recall deficits in patients with bipolar disorder. Prefrontal and limbic metabolism were inversely related.

CONCLUSION

Our findings demonstrate an association between prefrontal hypometabolism and paralimbic hypermetabolism and verbal memory deficits in euthymic older patients with bipolar disorder. Verbal memory deficits may be a clinical consequence of corticolimbic dysregulation in bipolar disorder, even during euthymia. This suggests that such dysregulation and related deficits could be bipolar disorder traits.

Neuropsychological functions in patients with bipolar I and bipolar II disorder

The literature reports persistent cognitive impairments in patients with bipolar disorder even after prolonged remission. However, a majority of studies have focused only on bipolar I disorder (BP-I), primarily because bipolar II disorder (BP-II) is often underdiagnosed or misdiagnosed. More attention should be paid to the differences between BP-I and BP-II, especially the aspects of neuropsychological functioning. We examined the different neuropsychological functions in BP-I and BP-II patients and compared them with those of healthy controls.

METHODS

The study included 67 patients with interepisode bipolar disorder (BP-I: n = 30; BP-II: n = 37) and 22 healthy controls compared using a battery of neuropsychological tests that assessed memory, psychomotor speed, and certain aspects of frontal executive function.

RESULTS

The BP-I group performed poorly on verbal memory, psychomotor speed, and executive function compared to the BP-II and control groups. Both bipolar groups performed significantly less well than the control group on measures of working memory and psychomotor speed, while the BP-II group showed an intermediate level of performance in psychomotor speed compared to the BP-I and control groups. There was no difference between the groups on visual memory.

CONCLUSIONS

BP-I was characterized by reduced performance in verbal memory, working memory, psychomotor speed, and executive function, while BP-II patients showed a reduction only in working memory and psychomotor speed. Cognitive impairment existed in both subtypes of bipolar disorder, and was greater in BP-I patients. Rehabilitation interventions should take into account potential cognitive differences between these bipolar subtypes.

Clinical predictors of functional outcome of bipolar patients in remission

OBJECTIVES

A number of studies have now shown that subjects with bipolar disorder (BD) have significant psychosocial impairment during interepisode intervals. This study was carried out to assess the level of functioning as well as to identify potential predictors of functioning in a well-defined, euthymic bipolar sample.

METHODS

The study included 71 euthymic bipolar patients and 61 healthy controls. The Functioning Assessment Short Test (FAST) was used to assess multiple areas of functioning such as autonomy, occupational functioning, cognitive functioning, interpersonal relationships, financial issues, and leisure time. Multivariate analysis was used to determine the global and specific clinical predictors of outcome.

RESULTS

Sixty percent (n = 42) of the patients had overall functional impairment (defined as a FAST total score > 11) compared to 13.1% (n = 8) of the control group (p = 0.001). Bipolar patients showed a worse functioning in all the areas of the FAST. Only four variables-older age, depressive symptoms, number of previous mixed episodes, and number of previous hospitalizations-were associated with poor functioning, on a linear regression model, which accounted for 44% of the variance (F = 12.54, df = 58, p < 0.001).

CONCLUSIONS

A substantial proportion of bipolar patients experience unfavorable functioning, suggesting that there is a significant degree of morbidity and dysfunction associated with BD, even during remission periods. Previous mixed episodes, current subclinical depressive symptoms, previous hospitalizations, and older age were identified as significant potential clinical predictors of functional impairment.

Fronto-temporal dysregulation in remitted bipolar patients: an fMRI delayed-non-match-to-sample (DNMS) study

OBJECTIVES

Bipolar disorder is associated with working memory (WM) impairments that persist during periods of symptomatic remission. However, the neural underpinnings of these deficits are not well understood.

METHODS

Fifteen clinically remitted bipolar patients and 15 demographically matched healthy controls underwent functional magnetic resonance imaging while performing a novel delayed-non-match-to-sample (DNMS) task. This nonverbal DNMS task involves two conditions, one requiring the organization of existing memory traces ('familiarity'), and one involving the formation of new memory traces ('novelty'). These processes are thought to differentially engage the prefrontal cortex and medial temporal lobe, respectively.

RESULTS

Although behavioral performance did not differ between groups, bipolar patients and controls exhibited significantly different patterns of neural activity during task performance. Patients showed relative hyperactivation in the right prefrontal gyrus and relative hypoactivation in visual processing regions compared to healthy subjects across both task conditions. During the novelty condition, patients showed a pattern of hypoactivation relative to controls in medial temporal regions, with relative hyperactivation in the anterior cingulate.

CONCLUSIONS

These findings suggest that disruption in fronto-temporal neural circuitry may underlie memory difficulties frequently observed in patients with bipolar disorder.

Treatment of bipolar disorder: new perspectives

Treatment of bipolar disorder (BD) has traditionally focused on alleviation of acute symptoms and prevention of future recurrences. Current treatment guide-lines advocate more or less similar treatment algorithms for all patients. Such approach largely ignores the clinical, genetic, and pathophysiological heterogeneity of BD, which makes certain patients more (or less) likely to respond to specific treatments. Variables such as family history, comorbidity, course of illness, quality and duration of previous remissions, physical and medical comorbidity, and side-effects may help in selecting the most effective treatment for an individual patient, yet their value is not recognized by current algorithms. As well, polymorphisms of specific genes may prove useful in predicting treatment outcome and/or understanding the pharmacological mechanisms of mood stabilization. Novel molecular targets have recently emerged from studies of mechanisms of action of available mood stabilizers. They include inhibitors of protein kinase C, inhibitors of glycogen synthase kinase, or medications modulating glutamatergic neurotransmission. As well, treatment targets are moving beyond acute symptoms and prevention of mood episodes. Cognitive deficits, persistence of residual symptoms, and increased mortality of BD are recognized as important for outcome of BD, yet are not always adequately addressed by traditional treatments.

The phenomenology of bipolar disorder: what drives the high rate of medical burden and determines long-term prognosis?

Bipolar disorder (BD) has been classically described as one of episodic mood disturbances. New evidence suggests that a chronic course and multisystem involvement is the rule, rather than the exception, and that together with disturbances of circadian rhythms, mood instability, cognitive impairment, a high rate of medical burden is often observed. The current diagnostic approach for BD neither describes the multisystem involvement that the recent literature has highlighted nor points toward potential predictors of long- term outcome. In light of the new evidence that the long-term course of BD is associated with a high prevalence of psychiatric comorbidity and an increased mortality from medical disease, we propose a multidimensional approach that includes several symptom domains, namely affective instability, circadian rhythm dysregulation, and cognitive and executive dysfunction, presenting in various combinations that give shape to each individual presentation, and offers potential indicators of overall long-term prognosis.

Cognitive functions in euthymic state of bipolar disorder: an Indian study

INTRODUCTION

It has recently been observed that some cognitive deficits in bipolar disorders persist even after the subsidence of active symptoms. The authors aim to study the cognitive functioning of patients with bipolar disorder, currently in euthymia and compare them with normal healthy controls.

METHODS

Fifteen patients having bipolar-I disorder and currently in euthymia were compared with fifteen age- and education-matched controlled subjects. Cognitive assessments were done using three computer-based tests, i.e., Wisconsin's Card Sorting Test (WCST), Spatial Working Memory Test (SWMT), and Continuous Performance Test (CPT).

RESULTS

Euthymic bipolar patients showed significant deficits in executive functions. Subtle deficits were present in attention and working memory that were not statistically significant.

CONCLUSIONS

Executive deficits may be trait markers in bipolar disorder and may have clinical implications in patient rehabilitation.

The cognitive and neurophysiological basis of emotion dysregulation in bipolar disorder

BACKGROUND

Bipolar disorder is characterized by fluctuating affect and mood, and is associated with specific neurocognitive deficits consistent with neuropathology in cerebello-striatal-prefrontal neural networks. This network is critical for emotion regulation.

METHODS

Relevant literature was located via PsychINFO and Medline to provide a comprehensive review of cognitive and neural mechanisms of social information processing and affect generation in bipolar disorder (BD) in the context of recent research examining the neural mechanisms of emotion regulation via conscious cognitive strategies.

RESULTS

Emotion regulation relies on synergy within brainstem, limbic and cortical processes that promote the adaptive generation and regulation of affect, with prefrontal and cingulate regions inhibiting sub-cortical and cortical emotion processing systems in the cognitive control of emotional experience. Current evidence of structural and functional brain abnormalities in BD alongside aberrant social cognition, affect generation, and neuropsychological function are consistent with a model of emotion dysregulation to account for the symptoms of BD.

LIMITATIONS

A precise understanding of emotion dysregulation in BD is currently limited by a paucity of longitudinal research directly examining these issues.

CONCLUSION

Aberrant emotion perception alongside increased limbic activity during emotion perception and affect generation in BD, alongside impaired executive control associated with aberrant neurophysiological abnormalities in sub-regions of the prefrontal cortex, is consistent with impaired emotion regulation. We propose a cognitive and neurophysiological framework within which the variations of mood that are characteristic of BD can be understood as specific impairments of the cognitive control of emotion.

Residual symptoms in bipolar disorder: the effect of the last episode after remission

In this study it is aimed to assess interepisode residual symptoms in remitted bipolar disorder patients with a hypothesis that the last episode recovered has implications on residual symptomatology. The study was carried out with 23 bipolar patients diagnosed as mania (BP-M) and 20 bipolar patients diagnosed as depression (BP-D) in their last episode, and with 22 healthy controls in a university hospital clinic. All patients were in remission for at least 6 months. In the assessment Hamilton Depression Rating Scale (HAM-D), Young Mania Rating Scale (YMRS), Stroop Test, Auditory Verbal Learning Test (AVLT), increased latency positive-evoked potentials (P300), Global Assessment of Functioning Scale (GAF), and Social Functioning Scale (SFS) were used cross-sectionally. In affective symptomatology, the BP-M group had higher YMRS scores, and the BP-D group had higher HAM-D scores compared to the controls. P300 test results revealed low amplitude in the BP-D group. In the AVLT, verbal learning and delayed recall were significantly lower in the two bipolar groups. The Stroop tasks were not different in the groups. Concerning the SFS, social withdrawal was impaired in the two bipolar groups, whereas dependency-competency was impaired in the BP-M and employment/occupation was impaired in the BP-D group. As a conclusion, bipolar patients recovering from depressive episode may experience more impairment in daily functioning due to residual depressive symptoms and impairment of attention and memory.

COMT genotype increases risk for bipolar I disorder and influences neurocognitive performance

OBJECTIVES

Bipolar disorder (BPD) is an affective disorder characterized by episodes of depression and mania. Cognitive impairment in patients with BPD is common and recent data suggest that it may represent a trait-like feature of the illness, as it persists during periods of wellness and co-segregates in families of bipolar patients. This suggests an underlying genetic predisposition towards cognitive impairment in patients with BPD; however, there have been few studies investigating the effects of candidate genes on this symptom domain. The catechol-O-methyl transferase (COMT) gene is located on chromosome 22q11 and is involved in the metabolism of dopamine and norepinephrine. A large body of evidence suggests that COMT is associated with cognitive performance in patients with schizophrenia and in healthy volunteers but there have been no reports of its relationship to cognition in BPD.

METHODS

We genotyped 52 Caucasian bipolar I probands and 102 Caucasian healthy controls across four single nucleotide polymorphisms (SNPs) within the COMT gene and administered a cognitive screening battery. We first assessed the relationship between COMT genotype and diagnosis and then tested for effects on cognition.

RESULTS

We observed a modest but significant association between SNP rs165599 and BPD I, with the g allele being over-represented in cases versus controls (odds ratio, OR = 2.41; allelic p = 0.02; genotypic p = 0.04). Further, we found a relationship between the risk allele at this SNP and poorer performance on measures of verbal memory [California Verbal Learning Test (CVLT) Trials 1-5; p = 0.005, eta(2) = 0.07] particularly with regard to prefrontal aspects of learning (CVLT semantic cluster; p = 0.037, eta(2) = 0.04) in patients with BPD and in healthy controls. The common Val158Met polymorphism was not associated with diagnosis (p = 0.32) or cognition in our sample.

CONCLUSIONS

These data suggest that COMT genetic variation at SNP rs165599 is associated with BPD I and influences prefrontal aspects of verbal memory in bipolar patients and healthy controls.

Neuropsychological symptom dimensions in bipolar disorder and schizophrenia

BACKGROUND

While neurocognitive (NC) impairments have been well documented in schizophrenia (SZ), there is limited data as to whether similar impairments are present in other persistent mental illnesses. Recent data indicate that NC impairments may be manifested in bipolar disorder (BPD) and that they persist across disease states, including euthymia. An important question is whether a comparable structure of NC impairments is present in the 2 diagnostic groups.

OBJECTIVE

In a previous factor analytic study, we identified 6 factors to describe the basic underlying structure of neuropsychological (NP) functioning in SZ: Attention, Working Memory, Learning, Verbal Knowledge, Non-Verbal Functions, Ideational Fluency. The goal of this study was to investigate whether this factor structure is generalizable for BPD.

METHODS

The BPD sample included patients (n = 155) from an ongoing longitudinal study evaluating BPD at the time of hospitalization for relapse and at multiple time points over the following 2 years. The SZ sample included patients (n = 250) from a 3-year study. For the current examination the baseline NP evaluations were selected for both samples.

RESULTS

Exploratory and confirmatory factor analyses in the BPD sample yielded factors similar to those identified in the SZ sample. The coefficients of congruence ranged between 0.66-0.90 for the individual factors, indicating a good overall correspondence between the factor structures in the 2 diagnostic groups. Analysis of covariance (ANCOVA) analysis with education level, full scale-IQ, gender and ethnicity as covariates indicated that SZ patients had markedly worse performance on the Attention and Non-Verbal Functioning factors compared to the BPD patients.

CONCLUSIONS

Together, these data suggest that while the same underlying factor structure describes NP functioning in both groups, the profile of impairments appears to vary with the diagnosis.

Functional outcome in bipolar disorder: the role of clinical and cognitive factors

INTRODUCTION

Few studies have examined the clinical, neuropsychological and pharmacological factors involved in the functional outcome of bipolar disorder despite the gap between clinical and functional recovery.

METHODS

A sample of 77 euthymic bipolar patients were included in the study. Using an a priori definition of low versus good functional outcome, based on the psychosocial items of the Global Assessment of Functioning (GAF, DSM-IV), and taking also into account their occupational adaptation, the patients were divided into two groups: good or low occupational functioning. Patients with high (n = 46) and low (n = 31) functioning were compared on several clinical, neuropsychological and pharmacological variables and the two patient groups were contrasted with healthy controls (n = 35) on cognitive performance.

RESULTS

High- and low-functioning groups did not differ with respect to clinical variables. However, bipolar patients in general showed poorer cognitive performance than healthy controls. This was most evident in low-functioning patients and in particular on verbal memory and executive function measures.

CONCLUSIONS

Low-functioning patients were cognitively more impaired than highly functioning patients on verbal recall and executive functions. The variable that best predicted psychosocial functioning in bipolar patients was verbal memory.

Cognitive impairment in bipolar II disorder

BACKGROUND

Persistent impairments in neurocognitive function have been described in bipolar disorder.

AIMS

To compare the cognitive performance of patients with bipolar II disorder with that of patients with bipolar I disorder and a healthy control group.

METHOD

The study included 71 euthymic patients with bipolar disorder (38 bipolar I, 33 bipolar II), who were compared on clinical and neuropsychological variables (e.g. executive function, attention, verbal and visual memory) and contrasted with 35 healthy controls on cognitive performance.

RESULTS

Compared with controls, both bipolar groups showed significant deficits in most cognitive tasks including working memory (DigitSpan Backwards, P=0.002) and attention (DigitSpan Forwards, P=0.005; Trail Making Test, P=0.001). Those with type II disorders had an intermediate level of performance between the bipolar I group and the control group in verbal memory (P<0.005) and executive functions (Stroop interference task, P=0.020).

CONCLUSIONS

Cognitive impairment exists in both subtypes of bipolar disorder, although more so in the bipolar I group. The best predictors of poor psychosocial functioning in bipolar II disorder were subclinical depressive symptoms, early onset of illness and poor performance on a measure related to executive function.

Cognitive functioning in bipolar patients receiving lamotrigine: preliminary results

Despite the increasing use of lamotrigine (LTG) in bipolar disorder, little is known about its impact on cognition in bipolar patients. Therefore, we have evaluated 33 bipolar I and II patients on cognitive measures (verbal memory, attention, executive functions) while receiving either LTG (n = 15) or another anticonvulsant (carbamazepine or valproate; n = 18). Patients receiving LTG were generally diagnosed as having bipolar II disorder, had experienced more depressive episodes but a lesser number of hospitalizations, and had better performance than the patients receiving carbamazepine or valproate on the verbal fluency task. A moderate effect size also suggests that both groups may differ on the immediate verbal memory test (California Verbal Learning Test). These preliminary results suggest a safer neurocognitive profile of LTG on bipolar patients, as compared with other anticonvulsants.

Persistent cognitive dysfunctions in bipolar I disorder and schizophrenic patients: a 3-year follow-up study

BACKGROUND

Neurocognitive impairment has consistently been considered a central and stable feature in schizophrenia. As this possibility has been far less studied in bipolar disorder, we aimed to prospectively investigate the stability and specificity of cognitive performance in bipolar disorder compared to schizophrenia.

METHODS

Fifteen DSM-IV bipolar type I patients and 15 schizophrenic patients were assessed twice with a comprehensive neuropsychological battery and the Positive and Negative Syndrome Scale over a 3-year follow-up. The cognitive performance of the groups was compared at baseline and 3 years later as a mean with that of 26 healthy volunteers. Endpoint and baseline assessments were also compared for each patient group in order to evaluate the stability of cognitive impairment.

RESULTS

At both time points, bipolar and schizophrenic patients showed significant deficits on most of the cognitive tasks compared to healthy subjects. Overall, the cross-sectional cognitive profile was similar for both patient groups. Moreover, after controlling for age and length of illness, the two groups' cognitive function did not differ over time in any test. With the exception of the Stroop color-word interference task, performance at baseline for each test but neither length of illness nor diagnostic category predicted the endpoint performance.

CONCLUSION

This preliminary study suggests that cognitive impairment is also mainly stable over time in bipolar I disorder and thus not specific to schizophrenia.

A pilot study of visual backward masking performance among affected versus unaffected offspring of parents with bipolar disorder

BACKGROUND

Cognitive dysfunction is evident in some euthymic patients with established bipolar disorder (BD), including deficits in visual backward masking (VBM) tasks which map to a specific neural pathway. A high-risk paradigm would clarify the temporal relation of cognitive dysfunction to clinical course.

METHOD

We compared euthymic offspring (age range: 18-32 years) of lithium-responsive bipolar parents with and without a previous lifetime history of psychiatric illness to healthy comparison subjects with a negative family history, on a VBM task that requires target location.

RESULTS

High-risk offspring with no lifetime psychiatric history performed the VBM task at levels of healthy controls. High-risk offspring with a previous history of a mood disorder, in complete remission, made significantly more errors at short target-mask intervals than control or never ill offspring. These higher error rates were not a consequence of faster response times.

CONCLUSIONS

There is preliminary evidence of specific cognitive dysfunction early in the course of illness in affected offspring of parents with lithium responsive BD. VBM is ideal for future longitudinal studies addressing whether cognitive dysfunction in BD is a trait marker or a consequence of illness manifestation.

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.

Testosterone's Analgesic, Anxiolytic, and Cognitive-Enhancing Effects May Be Due in Part to Actions of Its 5α-Reduced Metabolites in the Hippocampus

Although testosterone (T) may decrease anxiety and enhance cognitive performance, its mechanisms are not well understood. The authors hypothesized that if T's effects are mediated in part through actions of its 5alpha-reduced, nonaromatizable metabolite dihydrotestosterone (DHT) and/or its 3alpha-hydroxysteroid dehydrogenase reduced metabolite 3alpha-androstanediol (3alpha-diol) in the hippocampus, then T, DHT, and 3alpha-diol administration should produce similar behavioral effects concomitant with elevating T metabolites in the hippocampus. Gonadectomized male rats administered T, DHT, or 3alpha-diol via Silastic capsules or intrahippocampal infusions had greater analgesia (tail flick, paw lick), less anxiety behavior (plus-maze, open field, defensive freezing), and better learning (inhibitory avoidance) compared with vehicle control rats. Only 3alpha-diol levels in the hippocampus were consistently elevated in conjunction with these behavioral effects.