Autobiographical memory and its association with neuropsychological function in bipolar disorder

Processing speed and sustained attention in bipolar disorder and major depressive disorder: A systematic review and meta-analysis

OBJECTIVES

Cognitive impairment is a core feature of bipolar disorder (BD) and major depressive disorder (MDD). Deficits in processing speed (PS) and sustained attention (SA) may be particularly impaired and may underpin a broader profile of deficits, however current knowledge of the nature of these impairments is limited by heterogeneous results in the literature. Few reviews to date have attempted to disentangle sources of heterogeneity to assess the presence and magnitude of impairments in PS and SA in BD and MDD.

METHODS

One hundred and three studies were reviewed to examine performance in tests of PS and SA in BD (n = 3452) and MDD (n = 5461) compared to healthy controls (n = 8016). Neuropsychological methodology used in the literature was summarised. Data were meta-analysed to assess impairments in PS and SA for each neuropsychological test separately. Subgroup analysis was performed across mood states to investigate sources of heterogeneity.

RESULTS

Impairments were found across most neuropsychological tests, with small to large effect sizes for BD (range: d = 0.19-0.96) and MDD (range: d = 0.29-0.86). Impairments were present in symptomatic states and euthymia in most cases. Some outcome measures were not impaired in euthymia. Heterogeneity was observed for most neuropsychological tests and remained after separating by mood state. There inadequate data to meta-analyse some outcome measures, particularly for symptomatic groups.

CONCLUSION

Impairments in PS and SA in BD and MDD can be observed across most neuropsychological tests. Future research should further investigate the nature of these impairments across mood states, controlling for clinical confounds.

Difficulties in retrieving specific details of autobiographical memories and imagining positive future events in individuals with acute but not remitted anorexia nervosa

INTRODUCTION

The factors that contribute to the maintenance of anorexia nervosa (AN) are not fully understood, although it is generally accepted that depression is a core feature and contributes to poor prognosis. Individuals with depression tend to have difficulties in producing specific details of autobiographical memories and future episodes. Our aim was to investigate autobiographical memory and episodic future thinking (EFT) in individuals with AN (n = 46), people recovered from AN (recAN; n = 40), and non-affected controls (n = 35).

METHOD

Using a remotely administered computerised version of the autobiographical memory test and episodic future thinking task, we measured six aspects of memory retrieval and EFT generation: specificity, detailedness, difficulty in remembering/imagining, positivity, vividness and realism. Memory and EFT cue valence was manipulated; cues were either positive, neutral, or disorder-related/negative. As the production of EFTs is theoretically linked to the ability to retrieve autobiographical memories, the relationship between autobiographical memory specificity and EFT specificity was explored. To investigate whether autobiographical memory and EFT performance were independent of performance on other forms of cognition, working memory, verbal fluency and cognitive flexibility were measured.

RESULTS

People with AN had difficulties retrieving specific details of autobiographical memories and rated autobiographical memories as less positive overall, and less vivid when primed by positive cues. People with a lifetime diagnosis (currently ill or recovered) reported greater difficulty in retrieving memories. The AN group generated less positive EFTs, particularly to positive and neutral cues. Comorbid depressive symptoms had some contribution to the observed findings. Lastly, in all groups autobiographical memory specificity predicted EFT specificity.

DISCUSSION

Problems with retrieving specific details of autobiographical memories and simulating positive EFTs may be a state feature of AN. Treatments targeted at alleviating depressive symptoms, as well those targeted towards facilitating memory retrieval or reconsolidation, and the construction of positive EFTs, may contribute to hope for recovery and strengthen the sense of self beyond the disorder.

The stability of visual perspective and vividness during mental time travel

When remembering or imagining, people can experience an event from their own eyes, or as an outside observer, with differing levels of vividness. The perspective from, and vividness with, which a person remembers or imagines has been related to numerous individual difference characteristics. These findings require that phenomenology during mental time travel be trait-like-that people consistently experience similar perspectives and levels of vividness. This assumption remains untested. Across two studies (combined N = 295), we examined the stability of visual perspective and vividness across multiple trials and timepoints. Perspective and vividness showed weak within-session stability when reported across just a few trials but showed strong within-session stability when sufficient trials were collected. Importantly, both visual perspective and vividness demonstrated good-to-excellent across-session stability across different delay intervals (two days to six weeks). Overall, our results suggest that people dependably experience similar visual phenomenology across occurrences of mental time travel.

How to project oneself without positive and integrated memories? Exploration of self-defining memories and future projections in bipolar disorder

Bipolar disorder (BD) is a disabling disorder with functional impact on everyday life. Recent studies suggest that autobiographical memory impairment may contribute to the maintenance of psychopathology, leading to enduring altered self-construct. Moreover, past personal experiences also support the ability to project oneself into the future to pre-experience an event, this capacity can be modified by psychiatric disorders. Self-defining memories and future projections by accessing highly significant events that are vivid and focused on central goals or enduring concerns can both provide a better understanding of the impact of disorders on self-perception and on the ability to project oneself into the future. Therefore we proposed to explore self-defining memories and future projections in BD patients (n = 25) compared to control participants (n = 25). BD patients' self-defining events were associated with more tension, life-threatening events, and negative emotion. BD patients also reported less integrated past but not less integrated future self-defining events. And their future projections were more closely related to leisure, and associated with positive emotions, compared to controls. For both groups, the future projections were less specific, integrated, and tense than the memories. These results question the self-coherence of patients' identity and should be confirmed to propose appropriate interventions to project oneself adaptively into the future and contribute to a better outcome.

Role of autobiographical memory in the impact of MBCT on dysfunctional attitudes, depressive symptoms and anxiety in bipolar I patients

BACKGROUND

The literature suggests that cognitive reactivity in bipolar patients can increase relapse vulnerability, is enhanced by depressive mood and dysfunctional attitudes, and could be improved with MBCT. Autobiographical memory (AM) could be involved in cognitive reactivity, and improved with MBCT training. This study aims to investigate the effect of MBCT for bipolar patients on depressive and anxious symptoms, dysfunctional attitudes and AM, and the predictive versus mediating role of AM in the impact of MBCT on clinical symptoms.

METHODS

Sixty-two outpatients diagnosed with bipolar I disorder were assigned to MBCT and were compared to 37 bipolar patients on a waiting list. Affective symptoms and dysfunctional attitudes were explored using self-report inventories (BDI, BAI, DAS) and AM was assessed using the Autobiographical Memory Test.

RESULTS

Patients receiving MBCT demonstrated significantly decreased depressive symptoms, dysfunctional attitudes, overgeneral memories and omissions, and increased specific memories. General AM and omissions at baseline respectively predicted lower anxiety and dysfunctional attitudes improvement following therapy, but the improvement of AM did not explain the impact of MBCT on depression and dysfunctional attitudes improvement.

LIMITS

Further studies should consider patients' therapeutic adherence and mechanisms involved in MBCT in order to better apprehend how MBCT may reduce dysfunctional attitudes and improve AM in bipolar patients.

CONCLUSION

Results are consistent with the hypothesis that MBCT reduces cognitive reactivity and AM impairment in bipolar disorders. Findings suggest that AM training prior to MBCT may influence MBCT efficacy, but that MBCT efficacy on AM and clinical symptoms are non-related phenomena.

Number of episodes in bipolar disorder: The case for more thoughtful conceptualization and measurement

OBJECTIVES

Number of mood episodes (NoE) may be an important prognostic indicator in bipolar disorder, with implications for treatment. However, NoE has been conceptualized and measured inconsistently throughout the literature. This review examines the construct of NoE in bipolar disorder, with the aim of enhancing its conceptualization and measurement.

METHODS

A critical evaluation of literatures on important correlates of NoE, conceptually and phenomenologically overlapping features, and previous studies considering and measuring this construct was undertaken.

RESULTS

The literature indicates that despite frequent use, NoE has been inconsistently defined and measured. Multiple studies have linked NoE with important clinical factors, including relapse, functioning, cognitive impairment and the effectiveness of both pharmacological and psychosocial interventions, yet conclusions are limited by its inconsistent treatment. Additionally, it seems evident that that NoE may best be treated as a fuzzy construct (rather than precise figure), with yet to be defined overlaps with clinical variables such as age at onset and severity. Attempts to measure this construct have varied in comprehensiveness and structure.

CONCLUSIONS

The NoE construct may have important implications for individuals with bipolar disorders. However, more consistent and systematic definition and assessment of NoE is required to advance this literature and clarify its role. Recommendations aimed at advancing the conceptualization and the measurement of NoE are provided. Conceptualization may be advanced by considering and exploring relationships between NoE and factors with which it overlaps, while measurement may best be improved with increased consistency and balancing accuracy with feasibility.

Neurocognitive impairment and evidence-based treatment options in Bipolar disorder

BACKGROUND

The current paper briefly summarizes the literature on the neurocognitive deficit and its treatment in BD patients.

METHODS

The material was chosen on the basis of previous systematic reviews the author has taken part in.

RESULTS

The data so far suggest that the deficit is qualitatively similar but quantitatively milder in comparison to schizophrenia, it is present already since the first episode, is weakly related to mood symptoms and somewhat stronger to psychotic symptoms, it probably determines much of the disability and treatment is problematic. This deficit is also present during periods of euthymia. The possible adverse effect of psychotropic medication is rather small if any at all and is confounded by the specific clinical symptoms, for which medication is used for their treatment. This is especially true concerning antipsychotics and psychotic symptoms. The origin and the etiopathogenesis of the core neurocognitive impairment remain elusive. The presence of a neurodegenerative and of a neurodevelopmental component has both data in favor and against and they are both the focus of debate.

CONCLUSIONS

Treatment of the neurocognitive deficit and restoration of functioning is problematic. The data are limited and treatment options are few and with a weak overall effect. Pharmacological treatments, ECT and rTMS present some hard data, while the literature is inconclusive concerning psychotherapeutic interventions.

Cognitive and motor aspects of cancer-related fatigue

BACKGROUND

Cancer-related fatigue (CRF) is a debilitating symptom frequently reported by patients during and after treatment for cancer. CRF is a multidimensional experience and is often solely assessed by self-report measures. The goal of the study is to examine the physical and cognitive aspects of self-reported CRF using a cognitive function test and a physical fatigue index in order to provide objective measures that can characterize the CRF phenotype.

METHODS

A total of 59 subjects with nonmetastatic prostate cancer receiving external beam radiation therapy were included in the study. Fatigue was measured using the Functional Assessment of Cancer Therapy-Fatigue (FACT-F) questionnaire. Cognitive characteristics of CRF was measured using the Stroop Color-Word Interference computerized test and the motor aspect of fatigue was measured using the static fatigue test using a handgrip dynamometer.

FINDINGS

Functional Assessment of Cancer Therapy-Fatigue scores significantly correlated with the Stroop Interference score, but not performance accuracy in all test conditions. Fatigued subjects exhibited a more rapid decline to 50% of maximal strength and increased static fatigue index in the handgrip test, whereas maximal grip strength was not affected.

CONCLUSIONS

The results suggest that CRF exhibits both cognitive and physical characteristics. Subjective fatigue was associated with increased time required to overcome cognitive interference, but not cognitive performance accuracy. Fatigued patients exhibited decreased physical endurance and the ability to sustain maximal strength over time. These objective measures may serve as valuable tools for clinicians to detect cognitive and physical impairment associated with CRF.

Autobiographical memory deficits in remitted patients with bipolar disorder I: The effect of impaired memory retrieval

Autobiographical memory (AM) has been studied extensively in different psychiatric disorders. However, less is known about AM in bipolar disorder (BD). Aim of the present study was to investigate BD patients' ability to recall episodic and semantic autobiographical memories after controlling for the effect of other possible neurocognitive deficits. Participants included 30 clinically remitted outpatients with BD type I and 30 healthy controls, matched for age, gender and educational level. Autobiographical memory was examined by the Questionnaire of Autobiographical Memory. Premorbid intellectual functioning, verbal memory, verbal fluency, attention and working memory were also assessed. Bipolar patients were impaired in both episodic and semantic AM, compared with healthy individuals. Deficits involved recall of memories from childhood-adolescence, early adulthood and recent life. Additionally, patients were impaired in verbal memory compared with controls. Differences between study groups in both episodic and semantic AM remained significant even after controlling for the effect of verbal memory deficits. Remitted BD-I patients showed deficits in recalling personal episodic memories and facts dating to three different life periods. These deficits were independent of patients' lower verbal memory performance. Additional research is required to gain a better understanding of the pattern and the mechanisms underlying AM impairment in BD.

Self-reported inhibition predicts history of suicide attempts in bipolar disorder and major depression

BACKGROUND

Studies have reliably identified an association between suicide attempts and executive functions such as decision making (DM) and inhibitory control (IC) in patients with mood disorders. As such, the present study aimed to investigate the association between inhibition, DM, impulsivity and the history of suicide attempts in individuals with bipolar (BD) or major depressive disorder (MDD), identifying which assessment instruments may be most strongly associated with suicide in clinical samples.

METHODS

The sample included 80 control subjects and two groups of patients with BD and MDD, matched by age and education (26 with a history of suicide attempts [MD+], and 26 with no such history [MD-]). Participants completed behavioral and self-report measures of DM and IC, which were compared between groups using ANCOVA, followed by logistic regression for patients with mood disorders only, and the presence or absence of a history of suicide as the outcome.

RESULTS

Cognitive performance did not differ between groups. The MD+ group showed significantly higher motor and attentional impulsivity on the BIS-11 than the MD- and control groups. A regression analysis containing these scores showed that motor impulsivity was the only significant predictor of a history of suicide (OR = 1.14; 95%CI 1.00-1.30).

CONCLUSIONS

Self-reported motor impulsivity was a significant predictor of suicide. These findings underscore the importance of self-report measures in neuropsychological assessment, and their contributions to the management and prognosis of patients with mood disorders. Lastly, they point to the role of impulsivity as a target for interventions and public policy on suicide prevention.

Bipolar disorder and adherence: implications of manic subjective experience on treatment disruption

OBJECTIVE

Therapeutic observance is one of the cornerstones of bipolar disease prognosis. Nostalgia of previous manic phase has been described as a cause of treatment retrieval in bipolar disorder. But to date no systematic study has examined manic episode remembering stories. Our aim was to describe manic experience from the patient's point of view and its consequences on subjective relation to care and treatment adherence.

PATIENTS AND METHODS

Twelve euthymic patients with bipolar I disorder were interviewed about their former manic episodes and data was analyzed, thanks to a grounded theory method.

RESULTS

Nostalgia was an anecdotal reason for treatment retrieval in bipolar I disease. Although the manic experience was described as pleasant in a certain way, its consequences hugely tarnish the memory of it afterward. Treatment interruption appears to be mostly involuntary and state-dependent, when a euphoric subject loses insight and does not see any more benefit in having treatment.

CONCLUSION

Consciousness destructuring associated with mood elation should explain treatment disruption in bipolar I patients more than nostalgia. Taking a manic episode story into account may help patients, family, and practitioners to achieve better compliance by improving their comprehension and integration of this unusual experience.

Differential neural correlates of autobiographical memory recall in bipolar and unipolar depression

OBJECTIVES

Autobiographical memory (AM) recall is impaired in both bipolar depression (BD) and major depressive disorder (MDD). The current study used functional magnetic resonance imaging (fMRI) to investigate differences between healthy controls (HCs) and depressed participants with either BD or MDD as they recalled AMs that varied in emotional valence.

METHODS

Unmedicated adults in a current major depressive episode who met criteria for either MDD or BD and HCs (n=16/group) underwent fMRI while recalling AMs in response to emotionally valenced cue words. Control tasks involved generating examples from a given category and counting the number of risers in a letter string.

RESULTS

Both participants with BD and those with MDD recalled fewer specific and more categorical memories than HC participants. During specific AM recall of positive memories, participants with BD showed increased hemodynamic activity in the ventrolateral prefrontal cortex, posterior cingulate cortex, anterior insula, middle temporal gyrus, parahippocampus, and amygdala relative to MDD and HC participants, as well as decreased dorsolateral prefrontal (DLPFC) activity relative to MDD participants. During specific AM recall of negative memories, participants with BD manifested decreased activity in the precuneus, amygdala, anterior cingulate, and DLPFC along with increased activity in the dorsomedial PFC relative to MDD participants.

CONCLUSIONS

While depressed participants with BD and MDD exhibited similar depression ratings and memory deficits, the brain regions underlying successful AM recall significantly differentiated these patient groups. Differential amygdala activity during emotional memory recall (particularly increased activity in participants with BD for positive AMs) may prove useful in the differentiation of individuals with MDD and BD experiencing a depressive episode.

Self-reported symptoms of schizotypal and borderline personality disorder in patients with mood disorders

BACKGROUND

Distinguishing between symptoms of schizotypal (SPD) and borderline personality disorders (BPD) is often difficult due to their partial overlap and frequent co-occurrence. We investigated correlations in self-reported symptoms of SPD and BPD in questionnaires at the levels of both total scores and individual items, examining overlapping dimensions.

METHODS

Two questionnaires, the McLean Screening Instrument (MSI) for BPD and the Schizotypal Personality Questionnaire Brief (SPQ-B) for SPD, were filled in by patients with mood disorders (n=282) from specialized psychiatric care in a study of the Helsinki University Psychiatric Consortium. Correlation coefficients between total scores and individual items of the MSI and SPQ-B were estimated. Multivariate regression analysis (MRA) was conducted to examine the relationships between SPQ-B and MSI.

RESULTS

The Spearman's correlation between total scores of the MSI and SPQ-B was strong (rho=0.616, P<0.005). Items of MSI reflecting disrupted relatedness and affective dysregulation correlated moderately (rφ varied between 0.2 and 0.4, P<0.005) with items of SPQ. Items of MSI reflecting behavioural dysregulation correlated only weakly with items of SPQ. In MRA, depressive symptoms, sex and MSI were significant predictors of SPQ-B score, whereas symptoms of anxiety, age and SPQ-B were significant predictors of MSI score.

CONCLUSIONS

Items reflecting cognitive-perceptual distortions and affective symptoms of BPD appear to overlap with disorganized and cognitive-perceptual symptoms of SPD. Symptoms of depression may aggravate self-reported features of SPQ-B, and symptoms of anxiety features of MSI. Symptoms of behavioural dysregulation of BPD and interpersonal deficits of SPQ appear to be non-overlapping.

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

BACKGROUND

During the last decades, there have been many different opinions concerning the neurocognitive function in Bipolar disorder (BD). The aim of the current study was to perform a systematic review of the literature and to synthesize the data in a comprehensive picture of the neurocognitive dysfunction in BD.

METHODS

Papers were located with searches in PubMed/MEDLINE, through June 1st 2015. The review followed a modified version of the recommendations of the Preferred Items for Reporting of Systematic Reviews and Meta-Analyses statement.

RESULTS

The initial search returned 110,403 papers. After the deletion of duplicates, 11,771 papers remained for further evaluation. Eventually, 250 were included in the analysis.

CONCLUSION

The current review supports the presence of a neurocognitive deficit in BD, in almost all neurocognitive domains. This deficit is qualitative similar to that observed in schizophrenia but it is less severe. There are no differences between BD subtypes. Its origin is unclear. It seems it is an enduring component and represents a core primary characteristic of the illness, rather than being secondary to the mood state or medication. This core deficit is confounded (either increased or attenuated) by the disease phase, specific personal characteristics of the patients (age, gender, education, etc.), current symptomatology and its treatment (especially psychotic features) and long-term course and long-term exposure to medication, psychiatric and somatic comorbidity and alcohol and/or substance abuse.