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Bipolar disorder (BD) is associated with impaired psychosocial behaviours. Little is known about deficits in neurocognitive functions like decision-making possibly related both to these behaviours and to the nature of the disorder.
To determine whether decision-making impairments exist in manic (M), depressed (D) and euthymic (E) bipolar patients (BP) and to determine whether illness and course-of-illness characteristics can predict participants’ performance
A power analysis was conducted. A total of 315 subjects, including 45 M and 32 D inpatients and 90 E outpatients with BD I, medicated, and 150 Healthy Controls (HC), age, IQ and gender-matched, were included. Decision-making ability and sensitivity to punishment frequency were assessed with the Iowa Gambling Task (IGT).
On the IGT, MBP (p< 0.001), DBP (p< 0.01) and EBP (p< 0.05) selected significantly more cards from the risky decks than HC with no significant differences between BP groups. Unlike HC, MBP (p< 0.001), DBP (p< 0.05) and EBP (p< 0.05) showed little capacity to learn from incurred losses with no significant differences between BP groups, but, like HC, BP preferred decks that yielded infrequent penalties over those decks that yielded frequent penalties. In a multivariate analysis, decision-making impairment in the BP was significantly (p=0.001) predicted by low level of education, high total number of admissions and family history of BD.
BP clearly show defects in decision-making predicted by course-of-illness illness characteristics. Impaired decision-making might be a trait-related neurocognitive deficit in BD and partly explain impaired psychosocial behaviours of BP.
The low-mass end of the initial mass function remains poorly understood. In this mass range, very low-mass stars, brown dwarfs, and massive planets are able to form through a variety of physical processes. Here, we study the long-term evolution of disk-fragmented systems around low-mass stars, for the epoch up to 10 Myr (the typical lifetime of an embedded cluster) and up to 10 Gyr (the age of the Milky Way). We carry out N-body simulations to study the decay of disk-fragmented systems and the resulting end products. Our simulations indicate rapid decay and frequent physical collisions during the first 10 Myr. We find that disk fragmentation provides a viable mechanism for explaining hierarchical triple systems, the brown dwarf desert, single and binary brown dwarfs, and very low-mass binary systems in the solar neighbourhood.
Background: Despite the global impact of bipolar disorder (BD), treatment success is limited. Challenges include syndromal and subsyndromal mood instability, comorbid anxiety, and uncertainty around mechanisms to target. The Oxford Mood Action Psychology Programme (OxMAPP) offered a novel approach within a cognitive behavioural framework, via mental imagery-focused cognitive therapy (ImCT). Aims: This clinical audit evaluated referral rates, clinical outcomes and patient satisfaction with the OxMAPP service. Method: Eleven outpatients with BD received ImCT in addition to standard psychiatric care. Mood data were collected weekly from 6 months pre-treatment to 6 months post-treatment via routine mood monitoring. Anxiety was measured weekly from start of treatment until 1 month post-treatment. Patient feedback was provided via questionnaire. Results: Referral and treatment uptake rates indicated acceptability to referrers and patients. From pre- to post-treatment, there was (i) a significant reduction in the duration of depressive episode relapses, and (ii) a non-significant trend towards a reduction in the number of episodes, with small to medium effect size. There was a large effect size for the reduction in weekly anxiety symptoms from assessment to 1 month follow-up. Patient feedback indicated high levels of satisfaction with ImCT, and underscored the importance of the mental imagery focus. Conclusions: This clinical audit provides preliminary evidence that ImCT can help improve depressive and anxiety symptoms in BD as part of integrated clinical care, with high patient satisfaction and acceptability. Formal assessment designs are needed to further test the feasibility and efficacy of the new ImCT treatment on anxiety and mood instability.
Prior studies have suggested a relationship between atopy and mental health, although methodological barriers have limited the generalizability of these findings. The objective of this study was to investigate the relationship between early-life atopy and vulnerability to mental health problems among youth in the community.
Data were drawn from the Raine Study (N = 2868), a population-based birth cohort study in Western Australia. Logistic regression and generalized estimating equations were used to examine the relationship between atopy at ages 1–5 years [using parent report and objective biological confirmation (sera IgE)], and the range of internalizing and externalizing mental health problems at ages 5–17 years.
Atopy appears to be associated with increased vulnerability to affective and anxiety problems, compared to youth without atopy. These associations remained significant after adjusting for a range of potential confounders. No relationship was evident between atopy and attention deficit hyperactivity disorder or externalizing problems.
Findings are the first linking atopy (measured by both parent report and objective verification) with increased vulnerability to affective and anxiety problems. Therefore, replication is required. If replicated, future research aimed at understanding the possible biological and/or social and environmental pathways underlying these links is needed. Such information could shed light on shared pathways that could lead to more effective treatments for both atopy and internalizing mental health problems.
Aberrant emotional biases have been reported in bipolar disorder (BD), but results are inconsistent. Despite the clinical relevance of chronic mood variability in BD, there is no previous research investigating how the extent of symptom fluctuations in bipolar disorder might relate to emotional biases. This exploratory study investigated, in a large cohort of bipolar patients, whether instability in weekly mood episode symptoms and other clinical and demographic factors were related to emotional bias as measured in a simple laboratory task.
Participants (N = 271, BDI = 206, BDII = 121) completed an ‘emotional categorization and memory’ task. Weekly self-reported symptoms of depression and mania were collected prospectively. In linear regression analyses, associations between cognitive bias and mood variability were explored together with the influence of demographic and clinical factors, including current medication.
Greater accuracy in the classification of negative words relative to positive words was associated with greater instability in depressive symptoms. Furthermore, greater negative bias in free recall was associated with higher instability in manic symptoms. Participants diagnosed with BDII, compared with BDI, showed overall better word recognition and recall. Current antipsychotic use was associated with reduced instability in manic symptoms but this did not impact on emotional processing performance.
Emotional processing biases in bipolar disorder are related to instability in mood. These findings prompt further investigation into the underpinnings as well as clinical significance of mood instability.
Borderline personality disorder (BPD) and bipolar disorder (BD) have overlapping clinical presentations and symptoms – sources of persistent clinical confusion. Game-theory can characterize how social function might be sub-optimal in the two disorders and move the field beyond the anecdotal description of clinical history. Here, we tested the hypothesis that BPD and BD can be distinguished on the basis of diminished reciprocal altruism in iterated Prisoner's Dilemma (PD) games.
Twenty females with BPD, 20 females with euthymic BD and 20 healthy (non-clinical) females, matched for age and cognitive ability, were assessed for Axis-I and personality disorders, and completed psychometric measures of state affect, impulsivity and hostility. Participants completed two iterated PD games and a test of gaze-cueing.
In the PD games, BPD participants failed to show statistically stable preferences to cooperate with social partners (playing tit-for-tat) and made significantly fewer cooperative responses compared to BD or controls (ANOVA main effect p = 0.03, post-hoc Tukey p < 0.05 for both comparisons). BPD participants were also less likely to sustain cooperation following experiences involving mutual cooperation than the other groups. Neither BPD nor BD participants demonstrated impairments in shifting visual attention on the basis of other peoples’ gaze.
These data indicate that BPD is (selectively) associated with difficulties in establishing, and then maintaining, reciprocal cooperation, involving altruism. These difficulties are not seen in euthymic BD. Our data support the differentiation of BPD from BD and offer fresh insights into the social difficulties experienced by individuals with diagnoses of BPD.
Oxidative stress and neurotrophic factors have been implicated in the pathophysiology of bipolar disorder. Our objective was to determine whether plasma glutathione or brain-derived neurotrophic factor (BDNF) levels were abnormal in bipolar disorder and therefore useful as possible biomarkers.
Blood samples were collected from subsyndromal, medicated bipolar I patients (n = 50), recruited from OXTEXT, University of Oxford, and from 50 matched healthy controls. Total and oxidized glutathione levels were measured using an enzymatic recycling method and used to calculate reduced, percentage oxidized, ratio of reduced:oxidized and redox state. BDNF was measured using an enzyme-linked immunoassay. Self-monitored mood scores for the bipolar group were available (Quick Inventory of Depressive Symptomatology and the Altman Self-Rating Mania Scale) over an 8-week period.
Compared with controls, bipolar patients had significantly lower levels of total glutathione and it was more oxidized. BDNF levels were not different. Age of illness onset but not current mood state correlated with total glutathione levels and its oxidation status, so that lower levels of total and reduced glutathione were associated with later onset of disease, not length of illness.
Plasma glutathione levels and redox state detect oxidative stress even in subsyndromal patients with normal BDNF. It may relate to the onset and development of bipolar disorder. Plasma glutathione appears to be a suitable biomarker for detecting underlying oxidative stress and for evaluating the efficacy of antioxidant intervention studies.
A vascular plant species list and description is provided for the San Pastor Savanna, an isolated area of savanna within the Chiquibul Forest Reserve, Belize. Of the 126 species recorded, 28 are new records for the Chiquibul Forest Reserve with one previously unrecorded for the country. The maintenance of the current vegetation classification under the Belize Ecosystems Map for the San Pastor Savanna is supported. The coarse-textured soils are typical for extremely seasonal climates with some evidence of prolonged inundation during wet periods and dry seasons affected by burning. Although clear floristic affinities exist with other local and regional savanna areas, the San Pastor Savanna has some unique features and its flora includes national endemics. Although it is currently protected as part of the Chiquibul Forest Reserve and this status should be maintained, its inaccessible location makes frequent monitoring by the Forest Department problematic. Through providing a source of water and a source of forage for horses, the San Pastor Savanna plays a pivotal role in supporting the illegal Chamaedorea (xaté) palm leaf harvesting industry. This activity has also adversely impacted local wildlife. Like the nearby Mountain Pine Ridge, the San Pastor Savanna has suffered intense pine beetle (Dendroctonus spp.) attack.
Identifying prodromal features that predate the onset of bipolar disorder (BD) may enable the prevention of BD and aid early intervention. This review addresses two key questions: Is there a bipolar prodrome? And, if there is, what are its characteristic features?
A comprehensive search of databases (PubMed, Medline, EMBASE and PsycINFO) supplemented by hand searches was used to identify studies of symptoms preceding the onset of BD.
Fifty-nine studies were identified, of which 14 met inclusion criteria. Symptoms can predate the onset of BD by months to years and can be categorized as attenuated forms of BD symptoms, general symptoms common to a range of mental disorders, and personality traits, particularly cyclothymia. Two studies provided sufficient data to enable sensitivity and specificity to be calculated. Specificity of several of the features was high (>90%) but sensitivity was generally low (all <60%). We propose a model based on the findings in the studies reviewed to illustrate the potential trajectory to BD and the points at which it may be possible to intervene.
Clinical features preceding the onset of BD can be identified. However, conclusions about whether there is a distinct prodrome to BD are restricted by the limitations of current evidence. The high specificity of some features suggests they may be useful in clinical practice. Large-scale longitudinal studies are needed to validate these features and characterize their specificity and sensitivity in independent samples.
Administration of a complex tyrosine-free amino acid drink acutely decreases manic symptoms. Although a nutrient-based approach to illness management is attractive, complex amino acid drinks are too unpalatable for repeated administration.
To assess whether a simple, branched-chain amino acid (BCAA) drink diminishes manic symptoms acutely and following repeated administration.
Twenty-five patients with mania were randomly and blindly allocated to treatment with BCAA (60 g) or placebo daily for 7 days.
Relative to placebo, the BCAA drink lowered mania ratings acutely over the first 6 h of treatment. In protocol completers there was a persistent advantage to the BCAA group 1 week after the end of treatment.
A nutritional intervention that decreases tyrosine availability to the brain acutely ameliorates manic symptoms. Further studies are required to assess whether this approach has longer-term efficacy.
Treatment-resistant depression (TRD) is relatively common but its neurobiological basis is poorly understood. Fronto-striatal structural brain changes have been reported in patients with depression but their association with treatment resistance and chronicity has not been established.
Magnetic resonance images of 20 patients with TRD were compared with images of 20recovered patients and 20 healthy controls. Images were compared using a voxel-based analysis (VBA) method; the results were validated by conventional volumetric analysis. The clinical associations of magnetic resonance imaging (MRI) changes with illness duration and severity were examined by VBA.
Only the TRD group exhibited right fronto-striatal atrophy, and subtle MRI changes in the left hippocampus on VBA. Atrophy was confirmed on volumetric analysis, the degree correlating with the cumulative number of electroconvulsive therapy (ECT) treatments received, suggesting an acquired deficit.
This is the first study to demonstrate fronto-striatal atrophy in patients with depression with poor outcome; the atrophy is more marked in those with more severe illness.
A new two-volume edition of the sources and major analogues of all the Canterbury Tales prepared by members of the New Chaucer Society. This collection, the first to appear in over half a century, features such additions as a fresh interpretation of Chaucer's sources for the frame of the work, chapters on the sources of the General Prologue and Retractions, and modern English translations of all foreign language texts. Chapters on the individual tales contain an updated survey of the present state of scholarship on their source materials. Several sources and analogues discovered during the past fifty years are found here together for the first time, and some other familiar sources are re-edited from manuscripts closer to Chaucer's copies. Volume I includes chapters on the Frame and the tales of the Reeve, Cook, Friar, Clerk, Squire, Franklin, Pardoner, Melibee, Monk, Nun's Priest, Second Nun and Parson. Chapters on the other tales, together with the General Prologue and Retractions will appear in Volume Two. ROBERT M. CORREALE teaches at Wright State University, Ohio; MARY HAMEL teaches at Mount St Mary College, Maryland.