Sustained attention and executive functions in euthymic young people with bipolar disorder

Association of cannabis use with neurocognition in adolescents with bipolar disorder

BACKGROUND

Bipolar disorder (BD) and cannabis use are each associated with neurocognitive deficits in adolescents. However, little is known regarding the association of neurocognition with cannabis use among adolescents with BD. Therefore, we examined this topic in a sample of adolescents with BD and healthy control (HC) adolescents.

METHODS

Participants included 121 adolescents (n = 32 with BD and lifetime cannabis use (BDCB+), n = 31 with BD and no lifetime cannabis use (BDCB-), n = 58 HC with no lifetime cannabis use), aged 14-20 years. Five neurocognitive subtests of the computerized CANTAB battery were assessed. Groups were compared using an analysis of covariance (ANCOVA) covarying for age, sex, and intelligence quotient.

RESULTS

The three groups differed significantly on tests of visuospatial working memory (F = 4.41, p = 0.014, η p 2 = 0 . 07 ) and sustained attention (F = 5.15, p = 0.007, η p 2 = 0 . 08 ). Post hoc analyses revealed working memory scores were significantly worse in BDCB+ versus HC (p = 0.04, d = 0.59), and sustained attention was significantly worse in BDCB- versus HC (p = 0.006, d = 0.70).

CONCLUSION

These preliminary findings suggest that cannabis use among adolescents with BD is associated with working memory deficits. Future studies in larger samples are warranted to evaluate causation versus predisposition to cannabis use, and to evaluate duration, quantity, and potency of cannabis on neurocognition among adolescents with BD.

Single episode brief psychotic disorder versus bipolar disorder: A diffusion tensor imaging and executive functions study

BACKGROUND

Despite fast progress in neuroscientific approaches, the neurobiological continuum links psychotic spectrum, and affective disorder is obscure. White matter WM abnormalities found utilizing Diffusion Tensor Imaging (DTI) showing impaired communication in both disorders have been consistently demonstrated; however, direct comparisons of findings between them are scarce. This study aims to study WM abnormalities in single episode bipolar I disorder, and single episode brief psychotic disorder related to healthy control with the association of executive function.

METHODS

A cross-sectional case-control study was used to assess 60 subjects divided into 20 patients with single episode bipolar I disorder, 20 individuals with single episode brief psychotic disorder (both groups of patients were in remission), and 20 healthy controls. The present study examined the superior longitudinal fasciculus (SLF), and cingulum bundle fractional anisotropy (FA) determined from DTI images symmetrically and connected these results with cognitive functions as assessed by the trail making test (TMT) and Wisconsin card sorting test (WCST).

RESULTS

DTI data indicated that the psychotic group had a significant decrease in FA of the right SLF (p-value less than 0.001), left SLF (p-value less than 0.001), and left cingulum (p-value less than 0.001) than the bipolar I group. In terms of executive functioning, the psychotic group performed significantly worse than the bipolar I group on the TMT part B (p-value less than 0.001), the WCST (number of classifications fulfilled) (p-value less than 0.001), and perseverative errors (p-value less than 0.001).

CONCLUSION

Even after clinical remission, individuals with single episode brief psychotic disorder had more pronounced white matter impairments and executive function deficiencies than individuals with single episode bipolar I disorder.

Cognitive attentional syndrome and metacognitive beliefs as potential treatment targets for metacognitive therapy in bipolar disorder

Most treatment guidelines emphasize the use of psychotropic drugs for both the acute and maintenance treatment of bipolar disorder (BD). However, relying only on psychotropics without adjunctive psychosocial interventions may be insufficient in treating patients with BD. Given its unique view in the explanation of psychopathological states, metacognitive therapy (MCT) might be helpful for BD. Metacognitive theory posits that psychopathology is a result of the cognitive attentional syndrome (CAS) and that it is influenced and maintained by dysfunctional metacognitive beliefs, perseverative thinking, attentional biases, and dysfunctional coping strategies. In this review, literature data regarding these areas in BD are examined. Studies suggest that perseverative thinking might be among the emotion regulation strategies endorsed in individuals with BD. Regarding attentional biases, literature data show that state-dependent, mood-changing attentional biases and a ruminative self-focused attention are present. Studies also suggest that cognitive self-consciousness is higher in BD compared to controls. It is seen that maladaptive coping strategies are frequently reported in BD, and that these strategies are associated with depression severity, negative affect and relapse risk. Studies focusing on dysfunctional metacognitive beliefs in BD reported that individuals with BD had higher scores for negative metacognitive beliefs, self-consciousness, need to control thoughts, and a lack of cognitive confidence. Also, dysfunctional metacognitive beliefs were associated with depressive symptomatology. These findings suggest that the components of CAS and dysfunctional metacognitive beliefs are evident in BD. For a subgroup of patients with BD who fail to respond to evidence-based psychopharmacological and adjunctive psychotherapeutic interventions, MCT might be an alternative way to consider as a treatment option. In conclusion, taken the available data together, we propose a sequential treatment protocol for BD, mainly based on the MCT treatment plan of depressive disorders.

Magnetoencephalography resting-state spectral fingerprints distinguish bipolar depression and unipolar depression

OBJECTIVES

In clinical practice, bipolar depression (BD) and unipolar depression (UD) appear to have similar symptoms, causing BD being frequently misdiagnosed as UD, leading to improper treatment decision and outcome. Therefore, it is in urgent need of distinguishing BD from UD based on clinical objective biomarkers as early as possible. Here, we aimed to integrate brain neuroimaging data and an advanced machine learning technique to predict different types of mood disorder patients at the individual level.

METHODS

Eyes closed resting-state magnetoencephalography (MEG) data were collected from 23 BD, 30 UD, and 31 healthy controls (HC). Individual power spectra were estimated by Fourier transform, and statistic spectral differences were assessed via a cluster permutation test. A support vector machine classifier was further applied to predict different mood disorder types based on discriminative oscillatory power.

RESULTS

Both BD and UD showed decreased frontal-central gamma/beta ratios comparing to HC, in which gamma power (30-75 Hz) was decreased in BD while beta power (14-30 Hz) was increased in UD vs HC. The support vector machine model obtained significant high classification accuracies distinguishing three groups based on mean gamma and beta power (BD: 79.9%, UD: 81.1%, HC: 76.3%, P < .01).

CONCLUSIONS

In combination with resting-state MEG data and machine learning technique, it is possible to make an individual and objective prediction for mode disorder types, which in turn has implications for diagnosis precision and treatment decision of mood disorder patients.

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 Development in Patients with Bipolar Disorder and Metabolic Syndrome

OBJECTIVE

To describe and discuss current evidence on the relationship between cognitive performance, Bipolar Affective Disorder (BAD) and Metabolic Syndrome (MS).

METHODS

We searched for related articles in different bibliographic databases (MEDLINE, EMBASE, Scielo) and performed a narrative review of the literature with the selected articles.

RESULTS

To date, evidence has not been conclusive and the effect of MS on BD has not been widely studied, but important correlations have been observed with individual metabolic variables. It is suggested that obesity in patients with BAD is associated wotj worse performance in verbal memory, psychomotor processing speed, and sustained attention. Hypertriglyceridemia in patients with BAD appears to be associated with a lower score in executive function tasks; hypertension appears to be associated with impairment in overall cognitive function.

CONCLUSIONS

Despite the associations between MS and poor cognitive performance in patients suffering from BAD, more studies are required to precisely determine how these variables are related to each other.

Neurocognitive profile of patients with Bipolar Affective Disorder in the euthymic phase

Bipolar disorder is a chronic psychiatric condition characterized by episodes of elevated/irritable and depressed moods resulting in the loss of more disability-adjusted life years (DALYs) than other major conditions. The neurocognitive impairments in these patients interfere with sustained goal-directed performance and achievement even during the euthymic phase of the illness.

METHODOLOGY

The study aimed to explore the neurocognitive profile of patients in their euthymic phase. We matched 30 patients diagnosed with Bipolar Affective Disorder (BD) in the age range of 20-40 years with 30 healthy controls (with no axis I or II diagnosis, assessed on MINI) matched on age, gender, and education. The neurocognitive profile was assessed using NIMHANS Neuropsychology Battery.

RESULTS

Euthymic phase patients with bipolar disorder had statistically significant low scores on the speed of processing information as compared to healthy controls. Although impaired in BD group, no statistically significant difference was found between the two groups on executive functions and memory.

CONCLUSION

The findings of the study suggest that cognitive retraining aimed at ameliorating these deficits can be a used as an essential intervention in rehabilitation programs to successfully reintegrate patients with the bipolar affective disorder into the society. The research also indicates that despite the symptomatic recovery between the episodes, impairments in the speed of processing information continue to disrupt performance in patients with Bipolar Disorder.

Deficits in frontoparietal activation and anterior insula functional connectivity during regulation of cognitive-affective interference in bipolar disorder

OBJECTIVES

Bipolar disorders (BD) are characterized by emotion and cognitive dysregulation. Mapping deficits in the neurocircuitry of cognitive-affective regulation allows for potential identification of intervention targets. This study used functional MRI data in BD patients and healthy controls during performance on a task requiring cognitive and inhibitory control superimposed on affective images, assessing cognitive and affective interference.

METHODS

Functional MRI data were collected from 39 BD patients and 36 healthy controls during performance on the Multi-Source Interference Task overlaid on images from the International Affective Picture System (MSIT-IAPS). Analyses examined patterns of activation in a priori regions implicated in cognitive and emotional processing. Functional connectivity to the anterior insula during task performance was also examined, given this region's role in emotion-cognition integration.

RESULTS

BD patients showed significantly less activation during cognitive interference trials in inferior parietal lobule, dorsomedial prefrontal cortex, anterior insula, mid-cingulate, and ventrolateral prefrontal cortex regardless of affective valence. BD patients showed deviations in functional connectivity with anterior insula in regions of the default mode and frontoparietal control networks during negatively valenced cognitive interference trials.

CONCLUSIONS

Our findings show disruptions in cognitive regulation and inhibitory control in BD patients in the presence of irrelevant affective distractors. Results of this study suggest one pathway to dysregulation in BD is through inefficient integration of affective and cognitive information, and highlight the importance of developing interventions that target emotion-cognition integration in BD.

Single Dose of the Attention Training Technique Increases Resting Alpha and Beta-Oscillations in Frontoparietal Brain Networks: A Randomized Controlled Comparison

The Attention Training Technique (ATT) was developed with the aim of reducing self-focused attention and increasing executive control as part of metacognitive therapy. So far there is a paucity of data on the neurophysiological effects of ATT. In the present study we tested for specific effects to determine if attention control components of ATT elicit a specific signature that is different from passive listening. Thirty-six healthy volunteers were randomized to an active (follow instructions) or control (ignore instructions) condition. Resting state EEG was recorded for 3 min with eyes open and eyes closed before and after exposure to training, and the power of the theta, alpha, and beta-bands were analyzed in frontal, midline, and posterior electrodes. The active ATT condition enhanced alpha and beta-band activity during eyes-open, and frontal alpha during eyes-closed (p < 0.005). Frontoparietal changes in Alpha were generally accompanied by changes in Beta in the same brain regions of interest. However, these associations were largely significant in the active ATT rather than the control condition. No between-group differences were observed in the Theta-band. These results suggest a single dose of attention training increases alpha and beta-oscillations in frontoparietal networks. These networks are associated with top-down attentional or executive control.

Discovery biology of neuropsychiatric syndromes (DBNS): a center for integrating clinical medicine and basic science

BACKGROUND

There is emerging evidence that there are shared genetic, environmental and developmental risk factors in psychiatry, that cut across traditional diagnostic boundaries. With this background, the Discovery biology of neuropsychiatric syndromes (DBNS) proposes to recruit patients from five different syndromes (schizophrenia, bipolar disorder, obsessive compulsive disorder, Alzheimer's dementia and substance use disorders), identify those with multiple affected relatives, and invite these families to participate in this study. The families will be assessed: 1) To compare neuro-endophenotype measures between patients, first degree relatives (FDR) and healthy controls., 2) To identify cellular phenotypes which differentiate the groups., 3) To examine the longitudinal course of neuro-endophenotype measures., 4) To identify measures which correlate with outcome, and 5) To create a unified digital database and biorepository.

METHODS

The identification of the index participants will occur at well-established specialty clinics. The selected individuals will have a strong family history (with at least another affected FDR) of mental illness. We will also recruit healthy controls without family history of such illness. All recruited individuals (N = 4500) will undergo brief clinical assessments and a blood sample will be drawn for isolation of DNA and peripheral blood mononuclear cells (PBMCs). From among this set, a subset of 1500 individuals (300 families and 300 controls) will be assessed on several additional assessments [detailed clinical assessments, endophenotype measures (neuroimaging- structural and functional, neuropsychology, psychophysics-electroencephalography, functional near infrared spectroscopy, eye movement tracking)], with the intention of conducting repeated measurements every alternate year. PBMCs from this set will be used to generate lymphoblastoid cell lines, and a subset of these would be converted to induced pluripotent stem cell lines and also undergo whole exome sequencing.

DISCUSSION

We hope to identify unique and overlapping brain endophenotypes for major psychiatric syndromes. In a proportion of subjects, we expect these neuro-endophenotypes to progress over time and to predict treatment outcome. Similarly, cellular assays could differentiate cell lines derived from such groups. The repository of biomaterials as well as digital datasets of clinical parameters, will serve as a valuable resource for the broader scientific community who wish to address research questions in the area.

Biochemical abnormalities in basal ganglia and executive dysfunction in acute- and euthymic-episode patients with bipolar disorder: A proton magnetic resonance spectroscopy study

BACKGROUND

Recent studies found abnormal biochemical metabolism and executive cognitive deficits in acute bipolar disorder (BD). However, the evidence concerning in euthymic BD is limited. Thus, a comparison between acute and euthymic BD is conductive to better understanding the association between cognition and the outcome of neuroimaging. This study sought to investigate the relationship between the executive function and the biochemical metabolism in acute- and euthymic-episode BD patients and delineate the prominent endophenotype of BD.

METHODS

Three groups of participants were recruited in this study: 30 BD patients with an acute depressive episode, 22 euthymic BD patients, and 31 healthy controls. All participants were interviewed using the Structured Clinical Interview for DSM-IV, and underwent two-dimensional multivoxel proton magnetic resonance spectroscopy (1H-MRS) to obtain the bilateral metabolite levels in the lenticular nucleus of basal ganglia(BG). The ratios of N-acetylaspartate (NAA)/creatine (Cr) and Choline-containing compounds (Cho) /Cr ratios were calculated. Executive function was assessed by using the Wisconsin Card Sorting Test (WCST) and Trail Making Test, Part-B(TMT-B).

RESULTS

The comparison of biochemical changes showed that the NAA/Cr ratios in bilateral lenticular nucleus in both acute and euthymic BD patients was significantly lower than that in healthy controls at a confidence level of p<0.05. In the comparison of executive function, both acute and euthymic BD patients showed significantly decreased numbers of categories completed, and increased numbers of total errors, perseverative and noperseverative errors, and TMT-B uptake compared to the healthy controls at a confidence level of p<0.05. There were no significant differences between the acute BD and euthymic BD groups in the biochemical metabolite ratios and executive function. We found that the NAA/Cr ratio in the left in BG in the acute -episode BD patients was positively correlated with the number of categories completed, whereas it was negatively correlated with the total errors and TMT-B uptake. There was no correlation between the NAA/Cr and Cho/Cr ratios in the bilateral BG and the scores of SWCT and TMT-B in euthymic-episode BD patients.

LIMITATION

The sample size was relatively small and not all the euthymic-episode patients are the ones with an acute episode.

CONCLUSIONS

Our findings suggest that biochemical abnormalities in the lenticular nucleus and the executive dysfunction may occur early in the course of BD, and persist during remission, and are the most likely markers of endophenotypes of BD. The dysfunction of the neuronal function in the lenticular nucleus may be correlated with the cold dysfunction in patients with acute BD.

Neuropsychological profile of schizophrenia with and without obsessive compulsive disorder

Neuropsychological profile of schizophrenia with obsessive compulsive disorder (OCD) in comparison with that of schizophrenia without OCD is understudied and the results are inconsistent. We hypothesize that patients having schizophrenia with OCD ('schizo-obsessive disorder') may have unique neuropsychological deficits in comparison with those with schizophrenia alone, particularly with respect to executive functions. Thirty patients with schizo-obsessive disorder and 30 individually matched patients with schizophrenia without any obsessive-compulsive symptoms formed the sample of the study. Neuropsychological assessment included tests for attention, executive functions and memory. Patients with schizo-obsessive disorder did not differ from those with schizophrenia alone with respect to measures of attention, executive functions and memory. Our findings do not support unique neuropsychological profile of schizo-obsessive disorder. Studying a larger sample of drug-naive patients in a longitudinal design may provide us more insights in to this.

Potential neuroprotective effect of lithium in bipolar patients evaluated by neuropsychological assessment: preliminary results

OBJECTIVE

Accumulating evidence is delineating a neuroprotective/neurotrophic role for lithium. However, its primary effects on cognition remain ambiguous. We sought to investigate the profile of cognitive impairment in patients with bipolar disorder and to determine whether continued treatment with lithium preserves cognitive functioning.

METHODS

In this cross-sectional study, we tested 15 euthymic patients with bipolar I disorder undergoing long-term clinical maintenance treatment with lithium (for at least 12 months), 15 matched patients treated with other mood-stabilizing drugs and who had never received lithium, and 15 matched healthy subjects on the Cambridge Neuropsychological Test Automated Battery. Investigated cognitive domains were visual memory, executive functions, attention, decision-making/impulsivity, and response inhibition. We controlled for age, gender, intelligence, and residual psychiatric symptomatology.

RESULTS

Taken together, bipolar patients demonstrated robust deficits in visual memory and executive functions. Once subdivided in treatment subgroups, only non-lithium bipolar patients demonstrated impairments in visual memory. Attention, decision-making, and response inhibition were preserved in both groups. No correlation emerged between neuropsychological tests performance, clinical, and psychological variables.

CONCLUSIONS

This study is the first to our knowledge to have demonstrated, by means of a highly sensitive test of visual memory, a potential hippocampus neuroprotective effect of lithium in patients with bipolar disorder. Besides, it confirms prior findings of cognitive deficits in euthymic bipolar patients.

The neurocognitive profile of mood disorders - a review of the evidence and methodological issues

OBJECTIVES

Cognitive abnormalities are an established part of the symptomatology of mood disorders. However, questions still exist regarding the exact profile of these deficits in terms of the domains most affected, their origins, and their relationship to clinical subtypes. This review aims to examine the current state of the evidence and to examine ways in which the field may be advanced.

METHODS

Studies examining cognitive function in bipolar disorder (BD) and unipolar major depression (MDD) were examined. Given the number and variability of such studies, particular attention was paid to meta-analyses and to meta-regression analyses which examined the possible mediators of cognitive impairment.

RESULTS

Meta-analyses are available for MDD and BD in both depression and euthymia. Several analyses examine mediators. Results do not support the presence of domain specific deficits but rather a moderate deficit across a range of domains in BD and in MDD. The data on clinical mediators is inconsistent, even with regard to the effect of mood state.

CONCLUSIONS

A two-tiered approach, with the broad-based application of standardized measures on a large-scale, and the refined application of theoretically driven experimental development would significantly further our understanding of neurocognitive processing in mood disorder.

Cognitive impairment in manic bipolar patients: important, understated, significant aspects

BACKGROUND

Bipolar disorder is a chronic mood disorder with episodic progress and high relapse rate. Growing evidence suggests that individuals with bipolar disorder display cognitive impairment which persists even throughout periods of symptom's remission.

METHOD

137 bipolar patients met the inclusion criteria (depressive episode: DSM-IV-TR criteria for major depressive episode, HAMD score ≥17; manic/hypomanic episode: DSM-IV-TR criteria for manic/hypomanic episode, YMRS score ≥12, euthymic: 6 months of remission, HAMD score ≤8, YMRS score ≤6; and mixed: DSM-IV-TR criteria for mixed episode, HAMD score >8 and YMRS score >6) and were therefore enrolled in the study. Patients were free of psychotic symptoms (hallucinations/delusions) at the moment of testing. Control group consisted of 62 healthy subjects without history of neurological and/or psychiatric disorder. Cognitive battery has been applied in order to assess verbal memory, working memory, psychomotor speed, verbal fluency, attention and speed of information processing, and executive function. Following data were collected: demographics, psychiatric history, age of illness onset; current and previous treatment (including hospitalizations). Cognitive deficits were assessed in bipolar patients experiencing manic, depressive, mixed episodes or who were euthymic in mood. Results were compared between the subgroups and with healthy individuals. The association of impaired cognition with illness course was analyzed.

RESULTS

Bipolar patients showed cognitive deficits in all evaluated domains when compared to controls. The lowest scores were obtained for the verbal fluency test. After adjusting for current episode, manic subgroup showed greater cognitive impairment in verbal and working memory, executive function/reasoning and problem solving, compared to depressive, mixed, and euthymic subgroup. Low-neurocognitive performance was directly associated with a predominance of manic episodes and severe course of bipolar illness. An increased number of past manic episodes was the strongest correlated event with the poorest outcomes in verbal memory testing. Other factors correlated with poor verbal memory scores in manic subgroup were age at illness onset (positive correlation), illness length, and hospitalizations (negative correlations).

CONCLUSIONS

Bipolar patients showed cognitive deficits regardless of the phase of illness. Subjects experiencing a manic episode displayed higher deficits in verbal and working memory, executive function/reasoning, and problem solving. Severe course of illness also showed significant contribution in terms of cognitive impairment.

Neurocognitive intra-individual variability in mood disorders: effects on attentional response time distributions

BACKGROUND

Attentional impairment is a core cognitive feature of major depressive disorder (MDD) and bipolar disorder (BD). However, little is known of the characteristics of response time (RT) distributions from attentional tasks. This is crucial to furthering our understanding of the profile and extent of cognitive intra-individual variability (IIV) in mood disorders.

METHOD

A computerized sustained attention task was administered to 138 healthy controls and 158 patients with a mood disorder: 86 euthymic BD, 33 depressed BD and 39 medication-free MDD patients. Measures of IIV, including individual standard deviation (iSD) and coefficient of variation (CoV), were derived for each participant. Ex-Gaussian (and Vincentile) analyses were used to characterize the RT distributions into three components: mu and sigma (mean and standard deviation of the Gaussian portion of the distribution) and tau (the 'slow tail' of the distribution).

RESULTS

Compared with healthy controls, iSD was increased significantly in all patient samples. Due to minimal changes in average RT, CoV was only increased significantly in BD depressed patients. Ex-Gaussian modelling indicated a significant increase in tau in euthymic BD [Cohen's d = 0.39, 95% confidence interval (CI) 0.09-0.69, p = 0.011], and both sigma (d = 0.57, 95% CI 0.07-1.05, p = 0.025) and tau (d = 1.14, 95% CI 0.60-1.64, p < 0.0001) in depressed BD. The mu parameter did not differ from controls.

CONCLUSIONS

Increased cognitive variability may be a core feature of mood disorders. This is the first demonstration of differences in attentional RT distribution parameters between MDD and BD, and BD depression and euthymia. These data highlight the utility of applying measures of IIV to characterize neurocognitive variability and the great potential for future application.

How Does Mindfulness Meditation Work? Proposing Mechanisms of Action From a Conceptual and Neural Perspective

Cultivation of mindfulness, the nonjudgmental awareness of experiences in the present moment, produces beneficial effects on well-being and ameliorates psychiatric and stress-related symptoms. Mindfulness meditation has therefore increasingly been incorporated into psychotherapeutic interventions. Although the number of publications in the field has sharply increased over the last two decades, there is a paucity of theoretical reviews that integrate the existing literature into a comprehensive theoretical framework. In this article, we explore several components through which mindfulness meditation exerts its effects: (a) attention regulation, (b) body awareness, (c) emotion regulation (including reappraisal and exposure, extinction, and reconsolidation), and (d) change in perspective on the self. Recent empirical research, including practitioners' self-reports and experimental data, provides evidence supporting these mechanisms. Functional and structural neuroimaging studies have begun to explore the neuroscientific processes underlying these components. Evidence suggests that mindfulness practice is associated with neuroplastic changes in the anterior cingulate cortex, insula, temporo-parietal junction, fronto-limbic network, and default mode network structures. The authors suggest that the mechanisms described here work synergistically, establishing a process of enhanced self-regulation. Differentiating between these components seems useful to guide future basic research and to specifically target areas of development in the treatment of psychological disorders.

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.

Cognitive functions in euthymic Egyptian patients with bipolar disorder: are they different from healthy controls?

BACKGROUND

There is marked interest to research neurocognitive functions in bipolar disorder during euthymia. Consequently we aimed to study cognitive functions in euthymic bipolar patients and factors affecting them.

METHODS

It is a cross sectional case-control study of 60 euthymic bipolar patients and 30 matched healthy controls. They were subjected to: Structured Clinical Interview for DSM-IV disorders, (SCID-I) to ascertain clinical diagnosis, Young Mania Rating Scale (YMRS), Hamilton Rating Scale for Depression (HRSD) to validate euthymia. Wechsler Adult Intelligence Scale (WAIS) for general intellectual abilities, Wechsler Memory Scale-Revised (WMS-R) for memory, Wisconsin Card Sorting Test (WCST) for executive functions, Continuous Performance Test (CPT) for attention and impulsivity, and an information sheet gathering patient data.

RESULTS

Bipolar patients had statistically significant lower mean IQ scores in all WAIS subscales (p=0.000), significantly lower memory abilities especially digit span and visual memory, higher impulsivity and inattention (p=0.000) but no significant difference in response time by CPT. They displayed significantly lower executive performance on WCST. Patients' years of education correlated positively with IQ. Hospital admission, number, type of episodes and total number of episodes affected memory functions. Hospital admission and number of hypomanic episodes correlated with attention and impulsivity. Previous hospitalization correlated with executive functions.

CONCLUSIONS

Euthymic bipolar patients exhibit cognitive deficits, which correlated with clinical variables as number, type of episodes and previous hospitalization, this knowledge could help minimize cognitive impairments for future patients.

LIMITATIONS

The small sample size, cross sectional design and lack of premorbid cognitive assessment limit generalization of findings.

Systematic review of appropriate cognitive assessment instruments used in clinical trials of schizophrenia, major depressive disorder and bipolar disorder

Cognitive dysfunction is increasingly recognized as a symptom in mental conditions including schizophrenia, major depressive disorder (MDD), and bipolar disorder (BPD). Despite the many available cognitive assessment instruments, consensus is lacking on their appropriate use in clinical trials. We conducted a systematic literature review in Embase, PubMed/Medline and PsychINFO to identify appropriate cognitive function instruments for use in clinical trials of schizophrenia, MDD, and BPD. Instruments were identified from the articles. Instruments and articles were excluded if they did not address schizophrenia, MDD, or BPD. Instrument appropriateness was further assessed by the criteria of the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) initiative: test-retest reliability, utility, relationship to functional status, potential changeability to pharmacological agents, and tolerability and practicality for clinical trials. The database search yielded 173 articles describing 150 instruments used to assess cognitive function. Seventeen additional instruments were identified through Google and clinicaltrials.gov. Among all these, only 30 (18%) were deemed appropriate for use in the diseases of interest. Of these, 27 were studied in schizophrenia, one in MDD and two in BPD. These findings suggest the need for careful selection of appropriate cognitive assessment instruments, as not all may be valid in these disorders.

Impulsivity: present during euthymia in bipolar disorder? - a systematic review

Because impulsivity is part of the presentation of bipolar disorder (BD) and is associated with its course, this systematic review presents the evidence whether increased impulsivity is present in a stable, euthymic mood and therefore potentially a vulnerability marker for BD. A multi-faceted model of impulsivity was adopted to explore how different facets may relate differently to BD. The evidence was explored in relation to studies employing measures of trait impulsivity (in self-report format) and studies exploring impulsivity with behavioural paradigms. Behavioural paradigms were separated into studies measuring response inhibition and those measuring the ability to delay gratification. Twenty-three papers met the inclusion criteria. Most studies using self-report measures found significant differences between euthymic BD patients and healthy controls. There was little evidence of increased impulsivity as measured by behavioural paradigms. Most studies found no significant difference in response inhibition between groups, though it is possible that much of the literature in this area was underpowered to detect an effect. Only five studies explored delay of gratification, of which the two methodologically strongest studies found no group differences. In conclusion, there is evidence that euthymic patients with BD report increased impulsivity when using self-ratings. However, there is currently limited evidence of impulsivity on behavioural measures assessing response inhibition, and this might be restricted to more severe cases. More research is needed on the ability to delay gratification before drawing any conclusions. However, to establish facets of impulsivity as vulnerability markers, future studies should include at-risk individuals to evaluate whether self-rated or behavioural impulsivity precedes the onset of BD.

Cognitive functions and cognitive styles in young euthymic patients with bipolar I disorder

BACKGROUND

Recent evidences suggest that bipolar disorder patients do not return to premorbid functioning levels during the inter-episode periods. Cognitive deficits may impair patients working and functioning status and may also have negative impact on other aspects of thinking.

OBJECTIVES

To assess the prevalence of cognitive dysfunction in patients with bipolar disorder in euthymic state and to explore any evident cognitive style problems.

METHOD

Case-control naturalistic study 60 patients with bipolar I disorder in euthymic state according to DSM-IV were recruited and subdivided into two groups each contains of 30 patients; (Group BPM) euthymic patients with recent manic episode, and Group BPD euthymic patients with recent depressive episode. Both groups were further compared with control group (Group C) consisted of 30 frequency matched healthy volunteers. Groups were subjected to the following: 1-clinical psychiatric examination, 2-Hamilton Depression Scale (HAMD-17) and Bech-Rafaelsen Melancholia Scale (MES) for patients' group (BPD), 3-Young Mania Rating Scale (YMRS) and Bech-Rafaelsen Mania Scale (MAS) for patients' group (BPM), 4-assessment of euthymic state of mood included both MAS and MES, 5-MMSE, MTS and CDT were performed to assess cognitive functions, 6-cognitive styles evaluation included Fear of Failure, Hopelessness Scale, (the Social Dysfunction and Aggression Scale SDAS-9 and Arabic Anger Scale.

RESULTS

Definite cognitive function impairment and different patterns of cognitive style were detected in case groups. MMSE, MTS and CDT scores were statistically significant. Fear of Failure Scale Scores were higher in BPM; 16 (53.33%) reported severe intensity compared to 16 (53.33%) of BPD Group reporting moderate intensity and 30 (100%) of the control group reporting only mild intensity of fear of failure with statistically significant differences. Although patients were in euthymic state; Hopelessness Scale discriminated between those with affective disorders and controls and other scores for hostility SADS-9 and Arabic Anger Scale. Moreover, measures of cognitive styles showed differences among patients of the case groups who joined psychotherapy program in their management (28) compared to those who did not (32).

LIMITATION

Cognitive impact of psychotropic drugs could not be eliminated since the current study is naturalistic study.

CONCLUSIONS

Those with BAD in euthymic state suffer from cognitive dysfunction and some aspects of cognitive styles that may negatively interfere with their performance. Psychotherapeutic programs should consider these findings in their approaches for better impact on patients' quality of life and overall treatment outcome.

Conflict monitoring and adaptation in individuals at familial risk for developing bipolar disorder

OBJECTIVE

To examine conflict monitoring and conflict-driven adaptation in individuals at familial risk for developing bipolar disorder.

METHODS

We recruited 24 adolescents who had a parent with bipolar disorder and 23 adolescents with healthy parents. Participants completed an arrow version of the Eriksen Flanker Task that included trials with three levels of conflict: neutral, congruent, and incongruent flanks. Differences in performance were explored based upon the level of conflict in the current and previous trials.

RESULTS

Individuals at risk for developing bipolar disorder performed more slowly than youth with healthy parents in all trials. Analyses evaluating sequential effects revealed that at-risk subjects responded more slowly than youth of healthy parents for all trial types when preceded by an incongruent trial, for incongruent trials preceded by congruent trials, and for neutral and congruent trials when preceded by neutral trials. In contrast to the comparison group, at-risk adolescents failed to display a response time advantage for incongruent trials preceded by an incongruent trial. When removing subjects with attention-deficit hyperactivity disorder (ADHD), differences between groups in response time fell below significant level, but a difference in sequence modulation remained significant. Subjects at risk for bipolar disorder also displayed greater intra-subject response time variability for incongruent and congruent trials compared with the comparison adolescents. No differences in response accuracy were observed between groups.

CONCLUSIONS

Adolescents at risk for developing bipolar disorder displayed specific deficits in cognitive flexibility, which might be useful as a potential marker related to the development of bipolar disorder.

Impaired sustained attention in euthymic bipolar disorder patients and non-affected relatives: an fMRI study

OBJECTIVE

Behavioral deficits in sustained attention have been reported during both acute and euthymic phases of type I bipolar disorder (BD-I) and also in non-affected relatives of bipolar disorder (BD) patients. In particular, selective failure in target recognition was proposed as a potential trait marker for BD, but there are few studies exploring the neural correlates. The aim of the present study was to analyze the behavioral and functional magnetic resonance imaging (fMRI) response of euthymic BD-I patients and non-affected relatives during a sustained attention task.

METHODS

Twenty-four euthymic BD-I patients, 22 non-affected first-degree relatives of BD-I subjects, and 24 matched controls underwent a continuous performance test (CPT) with two levels of difficulty during event-related fMRI scanning.

RESULTS

Both patients and relatives showed a lower accuracy in target detection when compared to controls. The fMRI data analysis revealed between-group differences in several brain regions involved in sustained attention. During error in target recognition, both patients and relatives showed a larger activation in the bilateral insula and the posterior part of the middle cingulate cortex. By contrast, during correct target response, only patients failed to activate the right insula, whereas relatives showed an increased activation of the left insula and bilateral inferior parietal lobule - limited to the higher attention load - and an augmented deactivation of the posterior cingulate/retrosplenial cortex.

CONCLUSIONS

A selective impairment in target recognition during a CPT was behaviorally and functionally detectable in both euthymic BD-I patients and non-affected first-degree relatives, suggesting that specific sustained attention deficits may be a potential trait marker for BD-I.

Grey matter differences in bipolar disorder: a meta-analysis of voxel-based morphometry studies

OBJECTIVE

Several neuroimaging studies have reported structural brain differences in bipolar disorder using automated methods. While these studies have several advantages over those using region of interest techniques, no study has yet estimated a summary effect size or tested for between-study heterogeneity. We sought to address this issue using meta-analytic techniques applied for the first time in bipolar disorder at the level of the individual voxel.

METHODS

A systematic review identified 16 voxel-based morphometry (VBM) studies comparing individuals with bipolar disorder with unaffected controls, of which eight were included in the meta-analysis. In order to take account of heterogeneity, summary effect sizes were computed using a random-effects model with appropriate correction for multiple testing.

RESULTS

Compared with controls, subjects with bipolar disorder had reduced grey matter in a single cluster encompassing the right ventral prefrontal cortex, insula, temporal cortex, and claustrum. Study heterogeneity was widespread throughout the brain; though the significant cluster of grey matter reduction remained once these extraneous voxels had been removed. We found no evidence of publication bias (Eggers p = 0.63).

CONCLUSIONS

Bipolar disorder is consistently associated with reductions in right prefrontal and temporal lobe grey matter. Reductions elsewhere may be obscured by clinical and methodological heterogeneity.

Mindfulness based cognitive therapy improves frontal control in bipolar disorder: a pilot EEG study

BACKGROUND

Cognitive processing in Bipolar Disorder is characterized by a number of attentional abnormalities. Mindfulness Based Cognitive Therapy combines mindfulness meditation, a form of attentional training, along with aspects of cognitive therapy, and may improve attentional dysfunction in bipolar disorder patients.

METHODS

12 euthymic BD patients and 9 control participants underwent record of electroencephalography (EEG, band frequency analysis) during resting states (eyes open, eyes closed) and during the completion of a continuous performance task (A-X version, EEG event-related potential (ERP) wave component analysis). The individuals with BD completed an 8-week MBCT intervention and record of EEG was repeated.

RESULTS

(1) Brain activity, individuals with BD showed significantly decreased theta band power, increased beta band power, and decreased theta/beta ratios during the resting state, eyes closed, for frontal and cingulate cortices. Post MBCT intervention improvement over the right frontal cortex was seen in the individuals with BD, as beta band power decreased. (2) Brain activation, individuals with BD showed a significant P300-like wave form over the frontal cortex during the cue. Post MBCT intervention the P300-like waveform was significantly attenuated over the frontal cortex.

CONCLUSIONS

Individuals with BD show decreased attentional readiness and activation of non-relevant information processing during attentional processes. These data are the first that show, MBCT in BD improved attentional readiness, and attenuated activation of non-relevant information processing during attentional processes.

Suicide attempts in 107 adolescents and adults with kleptomania

Suicide attempts in kleptomania have received little investigation. This study examined rates, correlates, and predictors of suicide attempts in kleptomania. A total of 107 adolescent and adult subjects (n = 32 [29.9%] males) with DSM-IV kleptomania were assessed with standard measures of symptom severity, psychiatric comorbidity, and functional impairment. Subjects had high rates of suicide attempts (24.3%). The suicide attempt in 92.3% of those who attempted suicide was attributed specifically to kleptomania. Suicide attempts were associated with current and life-time bipolar disorder (p = .047) and lifetime personality disorder (p = .049). Individuals with kleptomania have high rates of suicide attempts. Bipolar disorder is associated with suicide attempts in individuals with kleptomania and underscores the importance of carefully assessing and monitoring suicidality in patients with kleptomania.

Neuropsychological performance in OCD: a study in medication-naïve patients

BACKGROUND

Obsessive-compulsive disorder (OCD) is associated with impairments in multiple neuropsychological domains but the findings are rather inconsistent across studies. One potential reason for poor replication is the confounding influence of medications. There is limited research on neuropsychological performance in medication-naïve, never treated OCD patients.

METHODS

In this study, we assessed 31 medication-naïve, never-treated, DSM-IV OCD patients free of comorbid major depression and 31 healthy controls individually matched for age, gender and years of education, with tests of attention, executive function, memory reasoning and visuo-spatial function.

RESULTS

Medication-naïve OCD patients did not significantly differ from healthy controls on most neuropsychological tests. Patients performed somewhat poorly only on the highest goal hierarchy of the Tower of London (TOL) test (p=0.001, effect size=0.68).

CONCLUSIONS

It is intriguing to find that symptomatic, drug-naïve OCD patients did not significantly differ from healthy controls on most neuropsychological tests. Our finding of medium effect size on TOL highest goal hierarchy test suggests that brain regions outside the affective orbitofrontal loop may also be perhaps involved in OCD. This finding however needs replication because of modest effect size. Future studies should focus on studying medication-naïve, co-morbidity-free patients and relatives using symptom dimensions for consistent and robust findings.

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.

The characteristics of a discrete mood episode, neuro-cognitive impairment and re-hospitalization in bipolar disorder

This longitudinal study examined characteristics of a discrete mood episode that predict re-hospitalization for bipolar disorder, highlighting associated cognitive dysfunction as a potential mechanism linking episode severity and relapse. Eighty-two inpatients meeting DSM-IV-TR diagnostic criteria for bipolar I disorder completed the study. Twenty-two of the patients were readmitted to the hospital within 3 months of discharge. The study compared these patients to the remaining 60 patients who were not readmitted to the hospital during this period. Patients were compared on several factors related to the severity of the mood episode and the course of illness more generally. Analysis also compared the groups on measures of mood and neuro-cognitive functioning, assessed 24-48 h before initial hospitalization discharge. Re-hospitalized patients had longer initial hospital stays (t = -3.10, p < 0.01), higher rates of psychosis while in the hospital (Chi square = 5.1, p < 0.02), and lower GAF scores on discharge (t = 2.37, p < 0.05). The groups did not differ in age of illness onset or number of previous psychiatric hospitalizations. With respect to neuro-cognitive functioning, analysis indicated poorer performance for re-hospitalized patients on measures of executive functioning (Wilks' Lambda, F (7, 71) = 9.0, p < 0.001), IQ (Wilks' Lambda, F (2, 76) = 5.06, p < 0.01), and memory (Wilks' Lambda, F (6,72) = 4.19, p < 0.001). Trends in the expected direction emerged for attention/working memory tests (Wilks' Lambda, F (7, 71) = 1.79, p < 0.10). Results highlight features of a discrete mood episode associated with increased rates of re-hospitalization. This study observed connections among episode severity, cognitive dysfunction at hospital discharge and re-hospitalization.

Neuropsychological functioning in adult bipolar disorder and ADHD patients: a comparative study

Bipolar disorder (BD) and adult attention deficit hyperactivity disorder (ADHD) usually manifest with shared clinical symptoms, proving quite challenging to thoroughly differentiate one from another. Previous research has characterized these two disorders independently, but no study compared both pathologies from a neuropsychological perspective. The aim of this study was to compare the neuropsychological profile of adult ADHD and BD with each other and against a control group, in order to understand the way in which comprehensive cognitive assessment can contribute to their discrimination as distinct clinical entities as well as their differential diagnosis. All groups were successfully matched for age, sex, years of education, and premorbid IQ. Participants were assessed with an extensive neuropsychological battery evaluating multiple domains. Compared to controls, BD patients had a poorer performance on immediate verbal memory tasks. Both clinical groups exhibited significantly lower scores than controls on the recognition phase of verbal and non-verbal memory tasks, as well as on a task of executive functioning with high working memory demand. Noticeably, however, ADHD had significantly better performance than BD on the recognition phase of both the Rey list memory task and the Rey Figure. The better performance of ADHD patients over BD may reflect the crucial role of the executive component on their memory deficits and gives empirical support to further differentiate the neuropsychological profile of BD and adult ADHD patients in clinical practice.

Cognitive functions among euthymic bipolar I patients after a single manic episode versus recurrent episodes

BACKGROUND

There is a growing consensus that persistent cognitive deficits are common in patients with bipolar disorders even when they are euthymic.

AIM

The aim was to assess objectively the presence of cognitive deficits in bipolar patients in remission, and to correlate these deficits with the recurrence of the disease.

METHODS

Cognitive functions (executive function, memory, intelligence, attention and concentration) of a group of euthymic bipolar patients after a single manic episode were compared to cognitive functions of patients who experienced recurrent episodes, both groups were assessed during remission. The results were compared with a control group, using SPSS.

RESULTS

Euthymic bipolar patients assessed after a single manic episode showed impairment in attention, executive functions and total memory score in comparison to healthy control subjects. While they performed better than Euthymic bipolar patients assessed after recurrent bipolar episodes as regards attention and executive function.

CONCLUSION

Bipolar disorder is associated with attention, memory and executive dysfunction. Attention and executive dysfunction is deteriorated by the recurrence of bipolar episodes.

Prefrontal and paralimbic metabolic dysregulation related to sustained attention in euthymic older adults with bipolar disorder

OBJECTIVE

  Reports of sustained attention deficits in the euthymic phase of bipolar disorder have been variable, and have yet to be related to cerebral metabolism. In the present study, we evaluated relationships between cognitive performance deficits and resting cerebral metabolism in euthymic older adults with bipolar disorder.

METHODS

  Sixteen older (mean age 58.7 years) euthymic outpatients with bipolar disorder (10 type I, 6 type II; 44% female) and 11 age-matched healthy controls received resting positron emission tomography with (18) fluorodeoxyglucose and, within 10 days, the Conners' Continuous Performance Test-II, a commonly used measure of sustained attention and inhibitory control.

RESULTS

  Bipolar disorder patients had significantly more omission errors (z = 2.53, p = 0.01) and a trend toward more commission errors (z = 1.83, p < 0.07) than healthy controls. Relative to healthy controls, among bipolar disorder subjects commission errors were more strongly related to inferior frontal gyrus [Brodmann area (BA) 45/47] hypometabolism and paralimbic hypermetabolism. In bipolar disorder subjects, relative to controls, omission errors were more strongly related to dorsolateral prefrontal (BA 9/10) hypometabolism and greater paralimbic, insula, and cingulate hypermetabolism.

CONCLUSIONS

  In older adults with bipolar disorder, even during euthymia, resting-state corticolimbic dysregulation was related to sustained attention deficits and inhibitory control, which could reflect the cumulative impact of repeated affective episodes upon cerebral metabolism and neurocognitive performance. The relative contributions of aging and recurrent affective episodes to these differences in bipolar disorder patients remain to be established.

Sustained attention as a potential endophenotype for bipolar disorder

OBJECTIVE

Nowadays, it is accepted that to identify the biological basis of psychiatric illnesses it would be useful to deconstruct them into the most basic manifestations, such as cognitive deficits. The aim of this study was to set attention deficit as a stable vulnerability marker of bipolar disorder.

METHOD

Sustained attention was evaluated by the Continuous Performance Test (DS-CPT) in 143 euthymic bipolar patients and 105 controls. To estimate the influence of clinical profile in attention, patients completed a semi-structured interview.

RESULTS

Bipolar patients showed a deficit in attention during euthymic periods. This disturbance correlated with years of evolution, age of onset and age of first hospitalisation; and was not influenced by other clinical data.

CONCLUSION

Sustained attention may be considered as an endophenotype of the illness.

Impairment of verbal learning and memory and executive function in unaffected siblings of probands with bipolar disorder

OBJECTIVES

Impairments in executive function and memory have been reported in relatives of patients with bipolar disorder, suggesting that they could be potential endophenotypes for genetic studies, but the findings are inconsistent. In this study, neuropsychological performance in unaffected siblings of probands with family loading for bipolar disorder is compared to that of individually matched healthy controls. We hypothesized that performance on tests of executive functions and memory would be impaired in unaffected siblings of probands with bipolar disorder compared to matched healthy controls.

METHODS

We evaluated 30 unaffected siblings of probands with bipolar I disorder and 30 individually matched healthy controls using tests of attention, executive function, and memory. Unaffected siblings and healthy control subjects did not differ with respect to gender, age, and years of education.

RESULTS

Unaffected siblings performed poorly on the Tower of London test (TOL), the Rey's auditory verbal learning test (RAVLT), and the Rey's complex figure test. In the multivariate analysis, significance was noted for the TOL, total number of moves (p = 0.007) and the RAVLT total learning score (p = 0.001).

CONCLUSIONS

Our study suggests that the deficits in verbal learning and memory and executive functions (planning) could be potential endophenotypes in bipolar disorder. These deficits are consistent with the proposed neurobiological model of bipolar disorder involving the frontotemporal and subcortical circuits. Future studies could couple cognitive and imaging strategies and genomics to identify neurocognitive endophenotypes in bipolar disorder.

Effects of recurrence on the cognitive performance of patients with bipolar I disorder: implications for relapse prevention and treatment adherence

OBJECTIVE

To determine if the repeated occurrence of manic episodes in bipolar I disorder (BD-I) patients is associated with reduced cognitive performance, which could in turn imply a worsening in the disorder's evolution.

METHOD

Cognitive performance in euthymic patients was assessed using attention, memory, and executive function tests on 24 BD-I patients who had experienced only 1 manic episode, on 27 BD-I patients with 2 manic episodes, on 47 BD-I patients with 3 or more manic episodes, and on 66 healthy control subjects.

RESULTS

In BD-I patients, number of manic episodes was positively associated with poorer performance on neurocognitive tests, an association that was not accounted for by depression, disease chronicity, onset, or medication. Significant differences in attention and executive function were found between patients and controls and in those patients who had had just 1 manic episode compared to those who had 3 or more.

CONCLUSION

The number of manic episodes predicted poor cognitive performance, suggesting that the recurrence of mania may have a long-term neuropsychological impact. Prospective follow-up studies need to be completed to explore this effect further as better treatment adherence may have a protective effect on neurocognitive function.

Indian psychiatry: Research and international perspectives

Indian psychiatry has many contributions to the world psychiatry to its credit. These include active participation in the international scientific organizations, research, and also creation of the manpower resources in many other countries. India has been an active partner in the research initiatives of the World Health Organization and the World Psychiatric Association. Research by the Indian psychiatrists played an important role in recognition of the entity of acute and transient psychotic disorders, some culture bound syndromes like Dhat syndrome and understanding the role of families in care of schizophrenia and course and outcome of schizophrenia.

A meta-analytic investigation of neurocognitive deficits in bipolar illness: profile and effects of clinical state

A meta-analysis of neuropsychological studies of patients with bipolar disorder comprised of 42 studies of 1,197 patients in euthymia, 13 studies consisting of 314 patients in a manic/mixed phase of illness, and 5 studies of 96 patients in a depressed state. Cohen d values were calculated for each study as the mean difference between patient and control group score on each neuropsychological measure, expressed in pooled SD units. For euthymia, results revealed impairment across all neuropsychological domains, with d values in the moderate-to-large range (d = .5 - .8) for the vast majority of measures. There was evidence of large effect-size impairment on measures of verbal learning (d = .81), and delayed verbal and nonverbal memory (d = .80 - .92), while effect-size impairment on measures of visuospatial function was small-to-moderate (d <or= .55). Patients tested during a manic/mixed or depressed phase of illness showed exaggerated impairment on measures of verbal learning, whereas patients tested during a depressed phase showed greater decrement on measures of phonemic fluency. These results suggest that bipolar illness during euthymia is characterized by generalized moderate level of neuropsychological impairment with particular marked impairment in verbal learning and memory. These results also show that a subset of these deficits moderately worsen during acute disease states.

Profound changes in dopaminergic neurotransmission in the prefrontal cortex in response to flattening of the diurnal glucocorticoid rhythm: implications for bipolar disorder

Patients with bipolar disorder have abnormalities in glucocorticoid secretion, dopaminergic neurotransmission, and prefrontal cortical function. We hypothesized that the flattening of the diurnal glucocorticoid rhythm, commonly seen in bipolar disorder, modulates dopaminergic neurotransmission in the prefrontal cortex (PFC) leading to abnormalities in prefrontally mediated neurocognitive functions. To address this hypothesis, we investigated the effects of a flattened glucocorticoid rhythm on (i) the release of dopamine in the PFC and (ii) the transcription of genes in the ventral tegmental area (VTA) coding for proteins involved in presynaptic aspects of dopaminergic neurotransmission. Male rats were treated for 13-15 days with corticosterone (50 microg/ml in the drinking water) or vehicle (0.5% ethanol). Corticosterone treatment resulted in marked adrenal atrophy and flattening of the glucocorticoid rhythm as measured by repeated blood sampling. Animals treated with corticosterone showed markedly enhanced basal dopamine release in the PFC as measured by microdialysis in the presence of a dopamine reuptake inhibitor. Depolarization-evoked release was also enhanced, suggesting that the corticosterone effect on basal release did not result from an increase in the neuronal firing rate. Local blockade of terminal D(2) autoreceptors failed to normalize release to control values, suggesting that the enhanced release was not because of reduced autoreceptor sensitivity. In situ hybridization histochemistry showed that mRNAs coding tyrosine hydroxylase and the vesicular monoamine transporter 2 were elevated in the VTA of corticosterone-treated rats. Our data show that flattening of the glucocorticoid rhythm increases dopamine release in the PFC possibly as a result of increased synthesis and vesicular storage. This provides a mechanistic explanation for prefrontal dysfunction in bipolar and other affective disorders associated with glucocorticoid dysrhythmia.

Fronto-temporal dysfunction in schizophrenia: A selective review

Schizophrenia is conceptualized as a disorder of aberrant neurodevelopment, with evident stigmata such as minor physical anomalies (MPA), neurological soft signs (NSS), and abnormalities of brain structure and function, proposed as disease endophenotypes. We have examined the neurobiology of schizophrenia using neurodevelopmental markers, structural MRI (sMRI), EEG spectral power, and coherence as well as neuropsychological testing in neuroleptic-naïve, recent-onset schizophrenia (NRS) subjects. It has been our focus to link the positive and negative symptom dimensions of schizophrenia with their underlying neural correlates specifically reflecting fronto-temporal circuitry dysfunction. We found that MPAs and NSSs constituted independent neurodevelopmental markers of schizophrenia and would afford greater predictive validity when used as a composite endophenotype. In an exploratory factor analytic study of the dimensionality of psychopathology, we noted that the symptoms segregated into three dimensions, viz., positive, negative, and disorganization, even in NRS subjects. Executive function tests as well as EEG spectral power and coherence studies revealed that the symptom dimensions of schizophrenia could be linked to specific neural correlates. In an attempt to study the relationship between the symptom dimensions and brain structure and function using MRI, we have proposed neuroanatomical definitions with cytoarchitectonic meaning for parcellation of the prefrontal sub-divisions. Using sMRI, we have found specific corpus callosal abnormalities that possibly link the temporo-parietal association cortices with the positive symptom dimension. Recently, we also found evidence for neurodevelopmental deviance in schizophrenia possibly involving the frontal pole (FP)-driven cortical network, in a sMRI study linking FP volume and total brain volume with age in NRS subjects and age-, gender- and education-matched healthy subjects. Overall, our findings highlight the potential significance of linking the homogeneous symptom dimensions of schizophrenia with dysfunctional connectivity in the fronto-temporal region.

Cognitive endophenotypes in OCD: a study of unaffected siblings of probands with familial OCD

BACKGROUND

Impairments in executive functions and non-verbal memory are considered potential endophenotype markers of obsessive-compulsive disorder (OCD). For the neuropsychological deficits to be considered endophenotypes, they should be demonstrable in unaffected family members.

AIM

To compare the neuropsychological performance in unaffected siblings of probands with familial OCD with that of individually matched healthy controls.

METHODS

Twenty-five unaffected siblings of OCD probands with familial OCD, and 25 individually matched healthy controls were assessed with tests of attention, executive function, memory and intelligence.

RESULTS

Unaffected siblings showed significant deficits in tests of decision making and behavioural reversal i.e., the Iowa Gambling Task (IGT) and the Delayed Alternation Test (DAT) respectively, but performed adequately in other tests.

CONCLUSIONS

Our study suggests that the deficits in decision making and behavioural reversal could be potential endophenotypes in OCD. These deficits are consistent with the proposed neurobiological model of OCD involving the orbitofrontal cortex. Future studies could couple cognitive and imaging strategies to identify neurocognitive endophenotypes in homogenous samples of OCD.

Increased intrasubject variability in response time in youths with bipolar disorder and at-risk family members

OBJECTIVE

Deficits in sustained attention may represent an endophenotype for bipolar disorder (BD). One heritable measure of sustained attention is intrasubject variability in response time (ISV-RT). We tested the hypothesis that, compared with controls, both youths with BD and those at familial risk for the disorder would have increased ISV-RT.

METHOD

Subjects were 28 patients with BD, 26 unaffected youths with a first-degree relative with BD, and 24 control youths without an affected relative, all aged 7 to 17 years. Subjects completed the Flanker Continuous Performance Test.

RESULTS

Bipolar disorder and at-risk youths had increased ISV-RT, compared with the controls. Differences were independent of comorbid psychopathology in youths with BD and present in psychiatrically healthy at-risk youths.

CONCLUSIONS

Increased ISV-RT may be a risk marker for BD. Further research is needed to investigate the neural and genetic underpinnings of this deficit, as well as the specificity of the finding to BD.

Structural abnormalities of ventrolateral and orbitofrontal cortex in patients with familial bipolar disorder

OBJECTIVES

Abnormalities of ventral prefrontal function have been widely reported in bipolar disorder, but reports of structural abnormalities in the same region are less consistent. We examined the presence and location of ventral prefrontal abnormalities in a large sample of individuals with bipolar disorder and their relationship to gender, psychotic symptoms, and age.

METHODS

Structural magnetic resonance imaging brain scans were carried out on 66 individuals with bipolar disorder, type I, and 66 controls. Voxel-based morphometry was used to examine differences in grey and white matter density between the groups and their relationship with a lifetime occurrence of psychotic symptoms and age.

RESULTS

Reductions in grey matter density were seen in the left and right lateral orbital gyri and the right inferior frontal gyrus, while white matter density reductions were seen in the corona radiata and the left temporal stem. In contrast, hallucinations and positive symptoms were associated with grey matter reduction in the left middle temporal gyrus. Age was more strongly associated with the right inferior frontal gyrus grey matter reductions in the bipolar group than in the controls, but not with any other finding.

CONCLUSION

Abnormalities of the ventral prefrontal cortex are likely to be involved in the aetiopathology of bipolar disorder, while hallucinations appear to be more closely associated with temporal lobe abnormality, extending earlier work in schizophrenia. Further prospective studies are required to comprehensively address the trajectory of these findings.