Between Bipolar Disorder Patients Research Articles

Comparison of olfactory function, cognitive function and serum tumor necrosis factor-α between bipolar and schizophrenic patients in the remission stage

ObjectivesOlfactory function, serum tumor necrosis factor-α (TNF-α) and cognitive function were compared between bipolar disorder (BD) and schizophrenia (SP) patients in the remission stage combined with correlation analysis, with the aim of identifying new indicators for the auxiliary diagnosis of these psychiatric illnesses.MethodsA total of 46 euthymic BD patients, 42 clinically stable SP patients and 42 healthy controls (HC) were included in this study. Olfactory sensitivity (OS) and olfactory identification (OI) were assessed using Sniffin’ Sticks test, and serum TNF-α levels were measured by ELISA. Clinical symptoms were evaluated with the Hamilton Rating Scale for Depression, Young Mania Rating Scale, Hamilton anxiety scale, and the Positive and Negative Syndrome Scale (PANSS). Social function was evaluated with the Global Assessment Function (GAF) scale. Cognitive function was evaluated using the Trail Making Test-A (TMT-A) and Digit Cancellation Test (DCT).ResultsOI and cognitive function scores and serum TNF-α levels were significantly lower in the BD and SP patients compared with the HC participants. There was no significant difference between the BD and SP groups, and there were no significant differences in OS among the three groups. OI score was positively correlated with years of education in both the BD and SP groups. OI score in the SP group was negatively correlated with age and PANSS score, and positively correlated with GAF score. In the BD group, OS was positively correlated with DCT II and DCT III. In the SP group, OS and OI scores were positively correlated with DCT III, and negatively correlated with TMT-A time. Furthermore, there was a positive correlation between TNF-α and DCT II in the BD group. There was no significant linear correlation between olfactory function and TNF-α in the BD or SP group.ConclusionOI may be a trait marker for BD and SP. Some cognitive functions may be correlated not only with TNF-α in BD patients in remission, but also with olfactory function in BD and SP patients in remission.

Differences and correlations of biochemical index levels in patients with bipolar disorder and major depressive disorder during a stable period.

The differences and correlation of biochemical indexes between bipolar disorder (BPD) and major depressive disorder (MDD) in stable stage were analyzed and discussed. Patients diagnosed with BPD and MDD in the Third People's Hospital of Foshan from January 2019 to December 2021 were selected as the research subjects, with 200 cases in each. Fasting serum was collected from patients and then detected regarding TC, TG, high-density lipoprotein, low-density lipoprotein (LDL), aspartate aminotransferase, lactic dehydrogenase, creatine kinase, creatine kinase-MB, urea, creatinine, uric acid, alanine aminotransferase, glucose (GLU), hemoglobin A1c, prolactin, high-sensitivity C-reactive protein, homocysteine. The results showed that the mean age and serum LDL, GLU, and HbAc1 levels of the MDD group were significantly higher than those of the BPD group (P < .05), while there was no significant difference in other indexes (P > .05). The prevalence of BPD was significantly negatively correlated with patient age (r = -0.164, P = .020), LDL (r = -0.150, P = .034), GLU (r = -0.140, P = .048), and HbAc1 (r = -0.215, P = .002) (P < .05). There were no significant differences in serum Hcy and high-sensitivity C-reactive protein levels between the BPD and MDD groups. The age, fasting blood glucose, glycosylated hemoglobin, and LDL of BPD patients were negatively correlated with their incidence.

Causal relationship between bipolar disorder and inflammatory bowel disease: A bidirectional two-sample mendelian randomization study.

Background: Growing evidence suggests a bidirectional association between bipolar disorder (BD) and inflammatory bowel disease (IBD); however, observational studies are prone to confounding, making causal inference and directional determination of these associations difficult. Methods: We performed bidirectional two-sample Mendelian randomization (MR) and selected single nucleotide polymorphisms (SNPs) associated with BD and IBD as instrumental variables (IV). SNPs and genetic associations with BD and IBD were obtained from the latest genome-wide association studies (GWAS) in Europeans (BD: cases/controls: 20352/31358; IBD: 12882/21770; Crohn’s disease (CD): 5,956/14927; ulcerative colitis (UC): 6968/20464). The inverse-variance-weighted method was the major method used in MR analyses. MR-Egger, weight mode, simple mode, and weighted median were used for quality control. Results: Genetically predicted BD (per log-odds ratio increase) was significantly positively associated with risk of IBD (OR: 1.18, 95% CI: 1.04–1.33), and UC (OR = 1.19, 95% CI: 1.05–1.35), but not CD (OR = 1.18, 95% CI: 0.95–1.48). The validation analysis found that combined OR of IBD, CD, and UC increased per log-OR of BD were 1.16(95% CI: 1.02–1.31), 1.20(95% CI: 0.98–1.48) 1.17(95% CI: 1.02–1.35), respectively. In contrast, no causal relationship was identified between genetically influenced IBD and BD. Conclusion: Our results confirm a causal relationship between BD and IBD, which may influence clinical decisions on the management of BD patients with intestinal symptoms. Although the reverse MR results did not support a causal effect of IBD on BD, the effect of the IBD active period on BD remains to be further investigated.

Subjects with bipolar disorder showed different reward system activation than subjects with major depressive disorder in the monetary incentive delay task.

Differentiating between bipolar disorder (BD) and major depressive disorder (MDD) during the depressive episode is an important clinical challenge. Reward system abnormalities have received much attention as one of the biological underpinnings of BD and MDD, but few studies have directly compared these abnormalities in remitted and depressed states. This was a functional MRI study using the Monetary Incentive Delay task in 65 patients (BD [n=33], MDD [n=32]) and 33 healthy controls (HC). Regions of interest (ROI) analysis with 21 ROIs related to reward anticipation and 17 ROIs related to gain outcome were implemented, as well as whole-brain analysis. The difference in the dimensional effect of depression on brain activation was also examined. Relative to the HC group, BD patients showed significantly decreased activation during reward anticipation in the anterior cingulate cortex, anterior insula (AI), and putamen, and MDD patients showed significantly decreased activation in the AI and brainstem. The dimensional effect of depression severity showed a trend-level difference between BD and MDD in the right brainstem and left AI. The current study showed a possible differential effect of depression on the reward system between MDD and BD. Further studies on reward systems might offer reliable markers to distinguish between MDD and BD patients in the depressive phase.

Explore functional brain changes in bipolar disorder: A whole brain ALE meta-analysis

ABSTRACT Background: Previous functional magnetic resonance imaging (fMRI) studies showed inconsistent results for comparison between bipolar disorder (BD) and healthy controls (HC). Methods: An anatomic likelihood estimation (ALE) meta-analysis was used to explore the key regions of brain pathology in BD with different current mood states. Results: Depressed BD patients showed reduced regional homogeneity (ReHo) in the left claustrum and the left middle frontal gyrus (MFG), compared to HC. BD patients with mixed mood status showed decreased fractional amplitude of low frequency fluctuations (fALFF) in the right cerebellar tonsil, the bilateral MFG and the right superior frontal gyrus, compared to HC. Additionally, BD patients with mixed mood status showed increased fALFF in the right inferior occipital gyrus, the right culmen and the left lentiform nucleus, compared to HC. BD patients with mixed mood status showed decreased functional connectivity (FC) in the bilateral cerebellar tonsil, compared to HC. Conclusion: In the present study, key regions undergoing functional deficits in BD patients with different current mood states were obtained with the ALE meta-analysis. In addition, deficits in these regions in fMRI studies might work as biomarkers for early diagnosis of BD.

Similar or Different Neuropsychological Profiles? Only Set Shifting Differentiates Women With Bipolar vs. Borderline Personality Disorder.

There is ongoing debate about the similarities and differences between bipolar disorder (BD) and borderline personality disorder (BPD). Very few studies have concurrently assessed their neuropsychological profile and only on a narrow array of neuropsychological tests. We aimed to investigate the differences of these two patient groups on visual memory, executive function, and response inhibition. Twenty-nine BD patients, 27 BPD patients and 22 controls (all female) were directly compared on paired associates learning (PAL), set shifting (ID/ED), problem solving (SOC), and response inhibition (SSRT) using Cambridge Neuropsychological Test Automated Battery (CANTAB). Rank-normalized outcomes were contrasted in one-way ANOVA tests. Discriminant analysis was finally performed to predict BD or BPD patient status. BD patients performed significantly worse than controls on all tasks. BPD patients performed significantly worse than HC on all tests except SST. Significant differences between the two patient groups were recorded only on ID/ED, where BPD patients performed worse (p = 0.044). A forward stepwise discriminant analysis model based on ID/ED and SOC predicted correctly patients' group at 67.9% of cases. In conclusion, BD and BPD female patients appear to be more similar than different as regards their neuropsychological functions. This study is the first to show that BPD patients display more deficits than BD patients when directly compared on the set shifting executive function test, a marker of cognitive flexibility. Discerning BD from BPD patients through neuropsychological performance is promising but would improve by using additional subtler tests and psychometric evaluation.

Pattern of occurrence of obsessive-compulsive symptoms in bipolar disorder

Apparent comorbidity between Bipolar Disorder (BD) and Obsessive-Compulsive Disorder (OCD) is a common condition, but its meaning has not been clarified yet. The present study aimed to evaluate the pattern of occurrence of obsessive-compulsive symptoms (OCS) in the different phases of BD. One hundred and sixty-five BD patients, 62 (37.5%) euthymic, 34 (20.6%) in hypomanic/manic phase, 43 (26%) in depressive phase and 26 (15.7%) in mixed state, were assessed with the Yale-Brown Obsessive-Compulsive Scale (YBOCS), the Hamilton Depression Rating Scale (HAM-D), the Young Mania Rating Scale (YMRS) and the Ruminative Response Scale (RRS). In the whole sample, the severity of OCS was associated to the severity of depressive symptoms. The highest severity of OCS (YBOCS total score) was observed in the mixed group and the lowest scores in the hypomanic/manic group. Our findings suggest that OCS in BD patients appear as a state-dependent phenomenon cycling with the mood phases, particularly exacerbating in the context of depressive and mixed states.

Evaluation of broad autism phenotype and handedness in patients with bipolar disorder

Objective: Genome-wide association studies of psychiatric disorders have revealed a multiplicity of common genetic variants between bipolar disorder (BD) and autism. It has been established that the frequency of affective psychosis is greater in individuals with autism. However, studies of the frequency of autism spectrum symptoms and autism-related hand preference in patients with BD are limited. The aim of this study was to investigate the broad autism phenotype and dominant hand preference in BD patients. Method: A total of sixty-six (thirty-three female) patients of the Bakirkoy Prof. Mazhar Osman Training and Research Hospital for Psychiatry, Neurology, and Neurosurgery mood clinic diagnosed with bipolar I disorder who were in a euthymic period and 66 healthy controls matched for gender, age, and years of education were enrolled in the study. Sociodemographic and clinical characteristics of the patients were obtained from patient records, and the Autism Spectrum Quotient test (AQ) and Edinburgh Handedness Inventory self-report screening tools were administered. Results: The mean disease duration was 15.5±8.4 years and the mean age of onset was 21.3±5.1 years. The mean total AQ score was 22.9±4.9 in the patient group and 19.1±4.4 in the control group, which represented a statistically significant difference. The mean score for the AQ subscales of communication, imagination, and attention switching were also higher in the patient group, and the difference was significant. Regression analysis indicated that the presence of BD was predictive for a higher AQ score; gender and hand preference did not demonstrate predictive value related to the AQ score. Conclusion: The results of this research indicated that the broad autism phenotype was common in BD. The broad autism phenotype should be kept in mind to better understand the clinical features of BD patients. Additional evaluation of the effect of the phenotypes including hand preference on the course of BD should be conducted in studies with larger samples.

Serum epidermal growth factor, clinical illness course, and limbic brain volumes in early-stage bipolar disorder

BackgroundEpidermal growth factor (EGF) belongs to a family of growth factors implicated in the etiology of psychiatric illnesses. We conducted this cross-sectional case-control study to determine whether (1) serum EGF levels differ between bipolar disorder (BD) patients and non-BD comparison subjects, (2) EGF levels in patients are influenced by mood illness related factors (number of past mood episodes, medication treatment) and non-mood illness related factors (body mass index), and (3) lower EGF levels predict lower limbic brain volumes in BD. MethodsWe measured serum EGF in 51 early-stage BD patients and 22 healthy comparison subjects (HS). A subset of 25 patients underwent cerebral magnetic resonance imaging (MRI). Participants were assessed at the University of British Columbia Mood Disorders Centre between June 2004 and June 2012. ResultsA general linear model with diagnosis and BMI category (overweight/obese vs normal weight) as factors showed that patients had lower mean log(e)-transformed EGF (LnEGF) than HS (4.99 vs 5.47, p = .011). There was no effect of BMI and no diagnosis x BMI interaction. Multiple linear regression models showed that in patients, more past mood episodes predicted lower LnEGF (β = −0.358, t = −2.585, p = .013) and lower LnEGF predicted lower bilateral temporal lobe volumes (left: β = 0.560, p = .011; right: β = 0.543, p = .009). LimitationsOur cross-sectional study design limits our ability to make inferences about the causal directions of the relationships between EGF, diagnosis, mood episodes, and brain volumes. ConclusionsThese findings provide preliminary evidence that EGF is a novel biomarker that may play a role in the pathophysiology of BD.

A comparison study of metabolic profiles, immunity, and brain gray matter volumes between patients with bipolar disorder and depressive disorder

BackgroundPrevious individual studies have shown the differences in inflammatory cytokines and gray matter volumes between bipolar disorder (BD) and unipolar depression (UD). However, few studies have investigated the association between pro-inflammatory cytokines and differences in brain gray matter volumes between BD and UD.MethodsIn this study, 72 BD patients and 64 UD patients were enrolled, with comparable gender and age distributions (33.8% males and an average age of 39.3 ± 13.7 years). Each participant underwent metabolic profiling (including body mass index (BMI), glucose, triglyceride, high-density lipoprotein (HDL), leptin, insulin, adiponectin), pro-inflammatory cytokine (including soluble interleukin-6 receptor (sIL-6R), soluble interleukin-2 receptor (sIL-2R), C-reactive protein (CRP), soluble tumor necrosis factor receptor type 1 (sTNF-R1) examinations, and structural magnetic resonance imaging exams. Voxel-based morphometry was performed to investigate the gray matter volume differences between BD and UD patients. Correlations between pro-inflammatory cytokines and the gray matter volume difference were analyzed.ResultsCompared to UD patients, the BD group had significantly higher BMI, and higher levels of sIL-6R and sTNF-R1 than the UD patients. The BMI significantly correlated with the level of pro-inflammatory cytokines. Adjusted for age, sex, BMI, duration of illness and total intracranial volume, the BD individuals had significantly more reduced gray matter volumes over 12 areas: R. cerebellar lobule VIII, R. putamen, L. putamen, R. superior frontal gyrus, L. lingual gyrus, L. precentral gyrus, R. fusiform gyrus, L. calcarine, R. precuneus, L. inferior temporal gyrus, L. hippocampus, and L. superior frontal gyrus. These 12 gray matter volume differences between BP and UD patients negatively correlated with sIL-6R and sTNF-R1 levels.ConclusionsOur results suggested that BD patients had higher BMI and pro-inflammatory cytokine levels in comparison to UD patients, especially IL-6 and sTNF-R1, which may contribute to greater gray matter reductions in BD patients in comparison to UD patients. The results support the neuro-inflammation pathophysiology mechanism in mood disorder. It is clinically important to monitor BMI, which, in this investigation, positively correlated with levels of inflammatory cytokines.

Updates in treating comorbid bipolar disorder and obsessive-compulsive disorder: A systematic review

BackgroundIn the last five years, the debate around the comorbidity between bipolar disorder (BD) and obsessive-compulsive disorder (OCD) has flourished within the international psychiatric community and several studies have been published on therapeutic strategies. MethodsAn update of our previous systematic review was conducted on clinical management of comorbid BD–OCD patients. Relevant papers published from July 1st 2013 to September 30th 2018 were identified searching the electronic databases MEDLINE, Embase, PsycINFO and the Cochrane Library. ResultsFifteen studies were included. In all selected studies BD–OCD patients received mood stabilizers, alone or with second-generation antipsychotics (SGAs). Aripiprazole augmentation demonstrated to be effective as maintenance therapy and for treating obsessive-compulsive symptoms during manic episodes (40% of the studies, 6/15). Addition of antidepressants to mood stabilizers led to clinical remission of both conditions in only one case report. LimitationsAlmost 50% of the selected studies are case reports. Enrolment of subjects mainly from outpatient specialty units might have introduced selection bias and limited community-wide generalizability. ConclusionsMood stabilization should be the primary goal in treating BD–OCD patients. Aripiprazole augmentation to lithium carbonate seemed to be the best option in treatment-resistance comorbid patients. Addition of SRIs may be needed only in a minority of BD patients with refractory OCD.

Predominant polarity in bipolar disorder patients: The COPE bipolar sample

The concept of predominant polarity (PP) is defined as presenting more symptoms of one polarity. Previous studies have defined PP as one polarity (either a depression or mania episode) occurring during at least two-thirds of the lifetime. We conducted an observational study with the COPE-BD (Clinical Outcome and Psycho-Education for Bipolar Disorder, Clinical Outcome Measures Section) dataset to identify the diagnostic and treatment differences between bipolar disorder (BD) patients with and without PP. The final sample included 210 BD-I (59.0%) and 146 BD-II (41.0%) patients. Of these, 28.9% patients presented predominant polarity (PP): 62 (17.4%) of those patients were depressed polarity predominant (DPP), 41 (11.5%) were manic polarity predominant (MPP), and 253 (71.1%) met criteria for bipolar disorders but did not present with PP. In comparison to this group of BD patients with undetermined polarity, the group of BD patients with PP presented more rapid cycling. Furthermore, in the undetermined polarity group, the onset of illness occurred earlier, and the duration of the illness was longer, with more hypomanic/manic and depressive episodes than patients who met the PP criteria. This study has a naturalistic and retrospective design and does not allow a specific follow-up of polarity over time. These different clinical characteristics underline the importance of considering PP in patients with BD, and justify the need for differential treatment approach which could have an impact on patients' prognosis. Yet, more independent and prospective research is needed to confirm these findings, especially with the new classification of DSM-5 concerning mixed states.

Can P300 aid in the differential diagnosis of unipolar disorder versus bipolar disorder depression? A meta-analysis of comparative studies

BackgroundIt is difficult to distinguish between bipolar disorder (BD) and unipolar disorder (UD) depression. Given the different pattern of cognitive impairments between BD and UD, P300 is potentially useful for the differential diagnosis. This meta-analysis was performed to estimate the extent of difference in P300 in patients with BD versus UD depression. MethodsStudies comparing P300 between depressed BD and UD patients with or without healthy controls (HCs) were retrieved from major English and Chinese databases. Studies with BD and UD samples that were comparable in terms of age, gender, and depression severity, were rated as having high quality. Standardized mean differences (SMDs) of P300 latency and amplitude were calculated. ResultsIn total, eight studies with a total of 397 depressed BD patients, 390 depressed UD patients, and 497 HCs, were included. Among included studies, six were rated as having good quality and three followed BD (n = 146) and UD (n = 144) patients during remission. BD patients had significantly longer P300 latency than UD patients during major depressive episode [SMD (95%CI): 0.580 (0.309, 0.850)] and remission [SMD (95%CI): 1.583 (1.322, 1.844)]. Compared to HCs, remitted BD patients still had significantly longer P300 latency [SMD (95%CI): 0.857 (0.059, 1.656)] but P300 latency of remitted UD patients had decreased to normal [SMD (95%CI): 0.536 (−0.272, 1.343)]. LimitationsSample sizes of depressed and remitted patients with BD and UD of included studies are small. ConclusionsP300 latency can be used as an auxiliary diagnostic marker for differentiating BD from UD depression.

Ruminative and dampening responses to positive affect in bipolar disorder and major depressive disorder

BackgroundAlthough previous research has focused on distinguishing cognitive styles between Bipolar Disorder (BD) and Major Depressive Disorder (MDD), little is known about differences in positive affect regulation between these affective groups. The aim of the present study was to extend previous research by investigating such differences between BD and MDD, and between the bipolar subtypes (BD-I vs. BD-II and predominant polarities), using large, clinical, outpatient samples. MethodsIn total, 298 participants (96 BD-I, 27 BD-II, and 175 MDD) were included. All completed the Responses to Positive Affect (RPA) questionnaire. Mood symptoms in BD patients were clinically assessed by means of the Clinical Global Impression for Bipolar Disorders (CGI-BP), while depressive symptom severity in MDD patients were assessed by means of the Inventory of Depressive Symptomatology (IDS-SR). ResultsResults showed differences between affective groups and bipolar subtypes. The most salient finding was that both BD-I and BD-II patients were more likely to ruminate about positive affect than MDD patients, while MDD patients were more likely to engage in dampening responses to positive affect. ConclusionsDifferentiation of responses to positive affect between BD and MDD may have relevant clinical implications in terms of symptomatology, course, and treatment.

The circulating levels of CD4+ t helper cells are higher in bipolar disorder as compared to major depressive disorder

IntroductionClinical differentiation between bipolar disorder (BD) and major depressive disorder (MDD) is difficult. Research has therefore focused on discriminatory biological markers. Previous studies in MDD reported T cell deficits, while the limited studies in BD reported T cell activation. Studies directly comparing circulating numbers of T cells and T cell subsets between BD and MDD are lacking. The studies in the MOODINFLAME consortium make such a comparison possible. MethodsThe number of circulating leukocyte populations (lymphocytes, monocytes, NK cells, B cells, T cells, CD3+CD8+ T cytotoxic cells, CD3+CD4+ T helper cells, Th1, Th2, Th17 and T regulatory cells) was determined using FACS technology in a cohort of 83 euthymic BD patients, 8 BD patients with a current mood episode and 165 healthy controls (HC). Data were compared to those of 34 moderately and 56 severely depressed MDD patients. ResultsCompared to MDD patients, BD patients showed significantly increased levels of Th17, Th2, Th1 and T regulatory cells (all p < .02). In BD patients, levels of Th17 and T regulatory cells were increased compared to HC (p = .03, p = .02, respectively), while MDD patients showed decreased levels of Th17 and Th2 compared to HC (p = .03, p = .01, respectively). Of the various medications only SSRI/SNRI usage could explain part of the Th2 decrease in MDD. ConclusionThis study shows CD4+ T helper cell deficits in MDD patients, while normal or even raised levels of these cells were found in BD patients. The differences in CD4+ T helper cell differentiation was most outspoken for Th17 cells.

A NATURALISTIC EXPLORATORY STUDY OF OBSESSIVE-COMPULSIVE BIPOLAR COMORBIDITY IN YOUTH

BackgroundGrowing evidence supports the comorbidity between bipolar disorder (BD) and obsessive-compulsive disorder (OCD) in children and adolescents. Our aim is to further explore clinical and treatment implications of this comorbidity, as it appears in clinical practice. MethodThe sample included 429 consecutive patients with BD and/or OCD as primary diagnoses, followed for a mean period of 6 months (range 4–9 months), 172 with BD (102 males, mean age 13.7±2.9 years), 169 with OCD (118 males, mean age of 13.2±2.7 years) and 88 with comorbid BD+OCD (56 males, mean age 14.2±2.6 years, 52 with BD as the primary diagnosis), followed for a mean period of 6 months (range 4–9 months). The comorbid group was compared to pure BD and OCD groups, to explore differential clinical and treatment features. ResultsThe BD-OCD comorbidity was found in 33.8% of the BD patients and in 34.2% of the OCD patients. Age at onset of BD and OCD were not different in pure and “comorbid” groups. The comorbid group presented a higher occurrence of BD type II and hoarding symptoms, and more frequently received a psychotherapy and second generation antipsychotics, but it presented the poorest outcome in terms of response to treatments. Severity at baseline (clinical severity and functional impairment), hoarding obsessions and compulsions, and conduct disorder comorbidity were associated with a treatment non-response. LimitationsA selection bias may have increased the rate of comorbidity, as most of the patients were referred to our tertiary hospital for severe BD and/or OCD and pharmacological treatment. We have used CGI-I as an outcome measure, not a specific measure of BD or OCD symptoms’ severity and improvement. The short duration of the follow-up may limit our conclusions. ConclusionsThe timely identification of BD-OCD comorbidity may have relevant clinical implications in terms of symptomatology, course, treatment and outcome.

Classification of Bipolar Disorder and Schizophrenia Using Steady-State Visual Evoked Potential Based Features

The accurate discrimination between bipolar disorder (BD) and schizophrenic patients is crucial because of the considerable overlap between their clinical signs and symptoms (e.g., hallucination and delusion). Recently, electroencephalograms (EEGs) measured in the resting state have been vastly analyzed as a means for classifying the BD and schizophrenic patients, but EEGs evoked by external audio/visual stimuli have been rarely investigated, despite their high signal-to-noise ratio (SNR). In this study, in order to investigate whether EEGs evoked by external stimuli can be used for classifying the BD and schizophrenic patients, we used a visual stimulus modulated at a specific frequency to induce steady-state visual evoked potential (SSVEP). In the experiment, a photic stimulation modulated at 16 Hz was presented to two groups of the schizophrenic and BD patients for 95 s, during which the EEG data were recorded. Statistical measures of SSVEPs (mean, skewness, and kurtosis) described in SNR units were extracted as features to characterize and classify the variations of brain activity patterns in the two groups. Two brain areas, O1 and Fz, showed a statistically significant difference between the two groups for SNR mean and kurtosis, respectively. Among five applied classifiers, k -nearest neighbor provided the highest classification accuracy of 91.30% with the best feature set selected by Fisher score. An acceptable accuracy for binary classification (>70%) was retained until analysis time was reduced up to 10 s using a support vector machine classifier, and 20 s for other classifiers. Our results demonstrate the potential applicability of the proposed SSVEP-based classification approach with relatively short single-trial EEG signals.

Shared and Specific Intrinsic Functional Connectivity Patterns in Unmedicated Bipolar Disorder and Major Depressive Disorder

Identifying brain differences and similarities between bipolar disorder (BD) and major depressive disorder (MDD) is necessary for increasing our understanding of the pathophysiology and for developing more effective treatments. However, the features of whole-brain intrinsic functional connectivity underlying BD and MDD have not been directly compared. We collected resting-state fMRI data from 48 BD patients, 48 MDD patients, and 51 healthy subjects. We constructed voxel-wise whole-brain functional networks and computed regional functional connectivity strength (FCS) using graph-theory and further divided the regional FCS into long-range FCS (lFCS) and short-range FCS (sFCS). Relative to the controls, both the BD and MDD patients showed decreased sFCS in the bilateral precuneus. In addition, the BD patients showed increased and the MDD patients showed decreased lFCS and sFCS in the bilateral cerebellum. The BD patients also showed increased lFCS in the right middle temporal gyrus and increased sFCS in the bilateral thalamus compared to either the MDD patients or the controls. These findings suggest that BD and MDD may have some shared as well as a greater number of specific impairments in their functional connectivity patterns, providing new evidence for the pathophysiology of BD and MDD at the large-scale whole brain connectivity level.

Neuropsychological differences between bipolar and borderline personality disorder patients

IntroductionThere is a continuing debate about the differences and similarities between bipolar disorder (BD) and borderline personality disorder (BPD).ObjectivesOnly few studies have focused on the neuropsychological profile of these two disorders.AimsWe studied the differences on memory, executive function and inhibitory control between BD and BPD patients.MethodsTwenty-nine patients with BD in euthymia, 27 patients with BPD and 22 healthy controls matched for age and education were included in the study. All of them were female. BD patients who could also be diagnosed with BPD were excluded from the study. Participants were administered a series of tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB), accessing memory, executive function and inhibitory control.ResultsBD and BPD patients performed worse than controls in general. Significant differences were found in the PAL test; BD patients had 46.71, BPD patients had 36.56 and controls had 15.77 errors (P = 0.004). BPD patients performed worse in the IE/ED set-shifting test; they made 48.16 errors while BD patients made 23.64 and controls 16.14 (P = 0.001). BPD patients performed better in the problem-solving task (SOC), they solved 10.0, BD patients 6.32 and controls 8.32 problems (P &lt; 0.001).BD and BPD patients had similar performance in the SST inhibition task but worse than controls (P = 0.03).ConclusionsBD and BPD seem to have differences in neuropsychological performance. BD patients show more deficits in memory learning and problem solving while BPD patients show more deficits in set shifting.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Prevalence of Circadian Rhythm Sleep-Wake Disorders and Associated Factors in Euthymic Patients with Bipolar Disorder.

Recent studies have suggested that there are certain pathophysiological relationships between bipolar disorder (BD) and circadian rhythm dysfunction. However, apparently no studies have clarified the prevalence of circadian rhythm sleep-wake disorders (CRSWD) in patients with BD. This study was set out to investigate the prevalence of CRSWD and associated factors in patients with BD. One hundred four euthymic BD outpatients participated in this study. The subjects were asked to answer questionnaires including demographic variables, clinical course of BD, and family history of psychiatric disorders and suicide. Severity of BD was assessed by the Montgomery-Åsberg Depression Rating Scale and Young Mania Rating Scale. CRSWD was diagnosed by clinical interview, together with sleep logs, according to the International Classification of Sleep Disorders, third edition (ICSD-3). Thirty-five subjects (32.4%) met the criteria for CRSWD. The age at the time of investigation and that at the onset of BD were both lower in the CRSWD group than in the non-CRSWD group. The rates of family history of psychiatric disorders and suicide in the CRSWD group were higher than those in the non-CRSWD group. Multiple logistic regression analysis revealed that the presence of CRSWD was significantly associated with younger onset age of BD and family history of suicide. The prevalence of CRSWD could be quite high in BD patients. Younger onset age of BD and family history of suicide were associated with presence of CRSWD in BD patients.