Search

Emerging evidence suggests that obesity impacts brain physiology at multiple levels. Here we aimed to clarify the relationship between obesity and brain structure using structural MRI (n = 6420) and genetic data (n = 3907) from the ENIGMA Major Depressive Disorder (MDD) working group. Obesity (BMI > 30) was significantly associated with cortical and subcortical abnormalities in both mass-univariate and multivariate pattern recognition analyses independent of MDD diagnosis. The most pronounced effects were found for associations between obesity and lower temporo-frontal cortical thickness (maximum Cohen´s d (left fusiform gyrus) = −0.33). The observed regional distribution and effect size of cortical thickness reductions in obesity revealed considerable similarities with corresponding patterns of lower cortical thickness in previously published studies of neuropsychiatric disorders. A higher polygenic risk score for obesity significantly correlated with lower occipital surface area. In addition, a significant age-by-obesity interaction on cortical thickness emerged driven by lower thickness in older participants. Our findings suggest a neurobiological interaction between obesity and brain structure under physiological and pathological brain conditions.

BackgroundMajor depressive disorder (MDD) is associated with an increased risk of brain atrophy, aging-related diseases, and mortality. We examined potential advanced brain aging in MDD patients, and whether this process is associated with clinical characteristics in a large multi-center international dataset.MethodsWe performed a mega-analysis by pooling brain measures derived from T1-weighted MRI scans from 29 samples worldwide. Normative brain aging was estimated by predicting chronological age (10-75 years) from 7 subcortical volumes, 34 cortical thickness and 34 surface area, lateral ventricles and total intracranial volume measures separately in 1,147 male and 1,386 female controls from the ENIGMA MDD working group. The learned model parameters were applied to 1,089 male controls and 1,167 depressed males, and 1,326 female controls and 2,044 depressed females to obtain independent unbiased brain-based age predictions. The difference between predicted “brain age” and chronological age was calculated to indicate brain predicted age difference (brain-PAD).FindingsOn average, MDD patients showed a higher brain-PAD of +0.90 (SE 0.21) years (Cohen’s d=0.12, 95% CI 0.06-0.17) compared to controls. Relative to controls, first-episode and currently depressed patients showed higher brain-PAD (+1.2 [0.3] years), and the largest effect was observed in those with late-onset depression (+1.7 [0.7] years). In addition, higher brain-PAD was associated with higher self-reported depressive symptomatology (b=0.05, p=0.004).InterpretationThis highly powered collaborative effort showed subtle patterns of abnormal structural brain aging in MDD. Substantial within-group variance and overlap between groups were observed. Longitudinal studies of MDD and somatic health outcomes are needed to further assess the predictive value of these brain-PAD estimates.FundingThis work was supported, in part, by NIH grants U54 EB020403 and R01 MH116147.

Abnormalities within frontal lobe gray and white matter of bipolar disorder (BD) patients have been consistently reported in adult and pediatric studies, yet little is known about the neurochemistry of the anterior white matter (AWM) in pediatric BD and how medication status may affect it. The present cross-sectional 3T 1H MRS study is the first to use a multivoxel approach to study the AWM of BD youth. Absolute metabolite levels from four bilateral AWM voxels were collected from 49 subjects between the ages of 8 and 18 (25 healthy controls (HC); 24 BD) and quantified. Our study found BD subjects to have lower levels of N-acetylaspartate (NAA) and glycerophosphocholine plus phosphocholine (GPC + PC), metabolites that are markers of neuronal viability and phospholipid metabolism and have also been implicated in adult BD. Further analysis indicated that the observed patterns were mostly driven by BD subjects who were medicated at the time of scanning and had an ADHD diagnosis. Although limited by possible confounding effects of mood state, medication, and other mood comorbidities, these findings serve as evidence of altered neurochemistry in BD youth that is sensitive to medication status and ADHD comorbidity.

The goal of this study was to compare brain structure between individuals with generalized anxiety disorder (GAD) and healthy controls. Previous studies have generated inconsistent findings, possibly due to small sample sizes, or clinical/analytic heterogeneity. To address these concerns, we combined data from 28 research sites worldwide through the ENIGMA-Anxiety Working Group, using a single, pre-registered mega-analysis. Structural magnetic resonance imaging data from children and adults (5–90 years) were processed using FreeSurfer. The main analysis included the regional and vertex-wise cortical thickness, cortical surface area, and subcortical volume as dependent variables, and GAD, age, age-squared, sex, and their interactions as independent variables. Nuisance variables included IQ, years of education, medication use, comorbidities, and global brain measures. The main analysis (1020 individuals with GAD and 2999 healthy controls) included random slopes per site and random intercepts per scanner. A secondary analysis (1112 individuals with GAD and 3282 healthy controls) included fixed slopes and random intercepts per scanner with the same variables. The main analysis showed no effect of GAD on brain structure, nor interactions involving GAD, age, or sex. The secondary analysis showed increased volume in the right ventral diencephalon in male individuals with GAD compared to male healthy controls, whereas female individuals with GAD did not differ from female healthy controls. This mega-analysis combining worldwide data showed that differences in brain structure related to GAD are small, possibly reflecting heterogeneity or those structural alterations are not a major component of its pathophysiology.

BackgroundBipolar disorder (BD) is a severe psychiatric disorder associated with structural and functional brain abnormalities, some of which have been found in unaffected relatives as well. In this study, we examined the potential role of decreased fractional anisotropy (FA) as a BD endophenotype, in adolescents at high risk for BD.MethodsWe included 15 offspring of patients with BD, 16 pediatric BD patients, and 16 matched controls. Diffusion weighted scans were obtained on a 3T scanner using an echo-planar sequence. Scans were segmented using FreeSurfer.ResultsOur results showed significantly decreased FA in six brain areas of offspring group; left superior temporal gyrus (LSTG; P P = .002), left banks of the superior temporal sulcus (LBSTS; P = .002), left anterior cingulum (LAC; P = .003), right temporal pole (RTP; P = .004) and left frontal pole (LFP; P = .017). On analysis, LSTG, LAC, and RTP demonstrated a potential to be an endophenotype when comparing all three groups. FA values in three regions, LBSTS, LTTG, and LFP were increased only in controls.ConclusionOur findings point at decreased FA as a possible endophenotype for BD, as they were found in children of patients with BD. Most of these areas were previously found to have morphological and functional changes in adult and pediatric BD, and are thought to play important roles in affected domains of functioning. Prospective follow up studies should be performed to detect reliability of decreased FA as an endophenotype and effects of treatment on FA.

Background The search for biomarkers of bipolar disorder (BD), including epigenetic alterations, has heavily relied on peripheral investigations that do not necessarily reflect brain-specific mechanisms. In this study we aimed to assess peripheral extracellular vesicles (EVs)’ microRNAs and determine their use as a novel source of biomarkers in BD. Methods We assessed peripheral blood EVs’ microRNAs from 20 patients with BD type I and 21 age- and sex-matched healthy controls by microarray, and further explored the predicted biological functions of significantly differentially expressed microRNAs. Results Our results identified 33 nominally significant microRNAs (p 1.5) altered in BD patients, including miRNAs previously reported to be altered in post-mortem tissues of patients. Pathway analyses identified some brain-relevant mechanisms enriched in these miRNAs, including axon guidance by netrin and the serotonin receptor pathway. Limitations Relatively small sample size, potential confounding effects of mood states, medication use, and comorbidities, analysis of total rather than brain-specific EVs, and lack of validation of significant miRNAs by other methods. Conclusions This study provides important preliminary evidence of the potential use of EVs as a novel source of biomarkers in BD. Overall, our findings of brain-relevant mechanisms in these vesicles suggest their potential use in living patients as a peripheral window to the brain.

Bipolar disorder (BD) is a chronic, debilitating illness with a global prevalence of up to 4.8%. The importance of understanding how dysfunctional mitochondria and mitophagy contribute to cell survival and death in BD is becoming increasingly apparent. Therefore, the purpose of this study was to evaluate the mitophagic pathway and NLRP3 inflammasome activation in peripheral blood mononuclear cells (PBMCs) of patients with BD and healthy individuals. Since 18-kDa translocator protein (TSPO) plays an important role in regulating mitochondrial function and since TSPO itself impairs cellular mitophagy, we also investigated the changes in the TSPO-related pathway. Our results showed that patients with BD had lower levels of Parkin, p62/SQSTM1 and LC3A and an upregulation of TSPO pathway proteins (TSPO and VDAC), both in terms of mRNA and protein levels. Additionally, we found a negative correlation between mitophagy-related proteins and TSPO levels, while VDAC correlated negatively with p62/SQSTM1 and LC3 protein levels. Moreover, we found that the gene expression levels of the NLRP3-related proteins NLRP3, ASC, and pro-casp1 were upregulated in BD patients, followed by an increase in caspase-1 activity as well as IL-1β and IL-18 levels. As expected, there was a strong positive correlation between NLRP3-related inflammasome activation and TSPO-related proteins. The data reported here suggest that TSPO-VDAC complex upregulation in BD patients, the simultaneous downregulation of mitophagic proteins and NLRP3 inflammasome activation could lead to an accumulation of dysfunctional mitochondria, resulting in inflammation and apoptosis. In summary, the findings of this study provide novel evidence that mitochondrial dysfunction measured in peripheral blood is associated with BD.

Emerging evidence suggests that obesity impacts brain physiology at multiple levels. Here we aimed to clarify the relationship between obesity and brain structure using structural MRI (n = 6420) and genetic data (n = 3907) from the ENIGMA Major Depressive Disorder (MDD) working group. Obesity (BMI > 30) was significantly associated with cortical and subcortical abnormalities in both mass-univariate and multivariate pattern recognition analyses independent of MDD diagnosis. The most pronounced effects were found for associations between obesity and lower temporo-frontal cortical thickness (maximum Cohen´s d (left fusiform gyrus) = −0.33). The observed regional distribution and effect size of cortical thickness reductions in obesity revealed considerable similarities with corresponding patterns of lower cortical thickness in previously published studies of neuropsychiatric disorders. A higher polygenic risk score for obesity significantly correlated with lower occipital surface area. In addition, a significant age-by-obesity interaction on cortical thickness emerged driven by lower thickness in older participants. Our findings suggest a neurobiological interaction between obesity and brain structure under physiological and pathological brain conditions.

In proton magnetic resonance spectroscopy (¹H MRS) studies, aberrant levels of choline-containing compounds that include glycerophosphocholine plus phosphocholine (GPC+PC), can signify alterations in the metabolism of cellular membrane phospholipids (MPLs) from a healthy baseline. In a recent ¹H MRS study, we reported increased GPC+PC in cortical and subcortical areas of adult patients with bipolar disorder I (BP-I). Post-traumatic stress disorder (PTSD) can worsen the severity of BP-I, but it is unclear whether the effect of a PTSD comorbidity in BP-I is associated with altered MPL metabolism. The purpose of this study was to re-investigate the ¹H MRS data to determine whether the regional extent of elevated GPC+PC was greater in BP-I patients with PTSD (BP-I/wPTSD) compared to BP-I without comorbid PTSD (BP-I/woPTSD) patients and healthy controls. GPC+PC levels from four brain areas [the anterior cingulate cortex (ACC), anterior-dorsal ACC, caudate, and putamen] were measured in 14 BP-I/wPTSD, 36 BP-I/woPTSD, and 44 healthy controls using a multi-voxel 1H MRS approach on a 3 Tesla system with high spatial resolution and absolute quantification. Results show a significant increase in GPC+PC levels from the caudate and putamen of BP-I/wPTSD patients compared to healthy controls (P

The neural mechanisms underlying the therapeutic effects of lamotrigine in bipolar depression are still unexplored. This preliminary study compares the effects of a 12-week treatment with lamotrigine on brain volumes in adults with bipolar disorder (BD).12 BD type II patients (age: 49.33 ± 9.95 years, 3 males, 9 females) and 12 age and gender-matched healthy controls (HC) (HC; age: 41 ± 8.60 years, 3 males, 9 females). BD patients were initially administered 25 mg/day of lamotrigine, which was progressively escalated to 200 mg/d. BD participants underwent brain imaging prior to and following lamotrigine treatment. A 50% reduction in depressive scores indicated “remission”. Bayesian general linear models controlled for age, gender and intracranial volume were used to examine changes in relevant brain region following treatment. A posterior probability > 0.90 indicated evidence that there was an effect of diagnosis or remission on brain volumes. Probability distributions of interaction effects between remission and time indicated that BD responders displayed decreased amygdala, cerebellum and nucleus accumbens volumes following lamotrigine treatment. No serious adverse side effects were reported. The antidepressant effects of lamotrigine may be linked to volumetric changes in brain regions involved in mood and emotional regulation. These findings are preliminary and replication in a larger sample is warranted.

Impulsivity is a well-established trait of bipolar disorder (BD) that persists across mood phases. It is, however, still unknown whether, in BD, impulsivity remains stable or varies in intensity over the lifespan. This cross-sectional study compared impulsive behavior in older euthymic BD patients and healthy individuals using a range of self-rating and behavioral measures of impulsivity.28 BD patients (56.07 ± 4.08 years, 16 women) and 15 healthy controls (HC; 55.1 ± 3.95 years, 6 women) were administered the Barratt Impulsivity Scale (BIS) and selected tasks of the Cambridge Neuropsychological Test Automated Batter (CANTAB) reflecting impulsivity. Multivariate analysis of variance controlled for age compared impulsivity measures across BD and HC.BD patients displayed poor decision making, risk taking, and increased delay aversion. Other measures of impulsivity such as response inhibition, sustained cognitive control, and BIS scores were, overall, comparable between BD and HC.These preliminary findings suggest that, in BD, aspects of impulsivity related to reward-based decision making persist into late adulthood. Large scale, longitudinal studies are needed to evaluate the relationship of age to impulsivity over time, and explore the link between impulsivity and illness progression in elderly individuals with BD.

Objective: Bipolar disorder (BD) is highly heritable. The present study aimed at identifying brain morphometric features that could represent markers of BD vulnerability in non-bipolar relatives of bipolar patients. Methods: In the present study, structural magnetic resonance imaging brain scans were acquired from a total of 93 subjects, including 31 patients with BD, 31 non-bipolar relatives of BD patients, and 31 healthy controls. Volumetric measurements of the anterior cingulate cortex (ACC), lateral ventricles, amygdala, and hippocampus were completed using the automated software FreeSurfer. Results: Analysis of covariance (with age, gender, and intracranial volume as covariates) indicated smaller left ACC volumes in unaffected relatives as compared to healthy controls and BD patients (p = 0.004 and p = 0.037, respectively). No additional statistically significant differences were detected for other brain structures. Conclusion: Our findings suggest smaller left ACC volume as a viable biomarker candidate for BD.

S100B is a calcium binding protein mainly produced by glial cells. Previous studies have shown elevated levels of S100B in patients with schizophrenia. We measured S100B levels in fasting plasma of 39 patients with schizophrenia and 19 adult healthy controls. We used linear regression to compare S100B between patients and controls. In patients only, we also investigated the relationship between S100B levels and psychotic symptoms (assessed by the Positive and Negative Syndrome Scale), and cognitive function (assessed by the NIH Toolbox Cognition Battery), respectively by calculating Pearson's correlation coefficients. Mean plasma S100B was significantly higher in the patient group than in the control group. There were no significant correlations between plasma S100B and psychotic symptoms or cognition.

OBJECTIVE To assess the global functioning and clinical outcomes of children and adolescents with bipolar disorder, children and adolescents with bipolar disorder and substance use disorder (SUD) comorbidity and healthy controls. METHODS This study had a cross-sectional design. Participants were children and adolescents aged between 6 and 17 years, and data were collected between 2003 and 2015. Psychiatric diagnosis was established according to DSM-IV criteria using the Kiddie-SADS-Present and Lifetime Version or the Mini-International Neuropsychiatric Interview for Children and Adolescents. Global functioning was assessed using the Children's Global Assessment Scale. Depressive symptoms were assessed using the Children's Depression Rating Scale. Manic symptoms were measured using the Young Mania Rating Scale, and the severity of anxious symptoms was assessed using the Screen for Child Anxiety Related Disorders. RESULTS The sample included 187 children and adolescents with bipolar disorder, 29 with BD and SUD comorbidity, and 115 healthy controls. Children and adolescents with BD and SUD comorbidity presented later onset of mood disorder (P < .001); higher rates of lifetime history of suicide attempt (P < .001), lifetime history of psychosis (trend toward significance: P = .076), and lifetime hospitalization (P < .001); and higher severity of depressive symptoms (trend toward significance: P = .080) as compared to those with BD without SUD comorbidity. In addition, both diagnosis groups presented higher rates of functional impairment when compared to controls (P < .001). Moreover, BD and SUD comorbidity presented higher functional impairment, as compared to BD without SUD comorbidity (P = .020). CONCLUSIONS Children and adolescents with bipolar disorder and substance use disorder comorbidity present a worse clinical course than those with bipolar disorder but without substance use disorder comorbidity.

Previous studies have found increased levels of choline-containing compounds (ie, glycerophosphocholine plus phosphocholine (GPC+PC)) in bipolar disorder using in vivo proton magnetic resonance spectroscopy (1H MRS), especially in bipolar I disorder (BD-I). Increased levels of GPC+PC suggest alterations in the membrane phospholipids metabolism in bipolar disorder. Rapid cycling (RC) bipolar disorder is considered as a severe course of bipolar disorder, but it is unclear whether rapid cycling bipolar disorder is linked to highly altered membrane phospholipid metabolism. The purpose of this study was to investigate whether the regional extent of elevated GPC+PC were greater in BD-I patients with rapid cycling compared to BD-I patients without rapid cycling and healthy controls. Using a multi-voxel 1H MRS approach at 3 Tesla with high spatial resolution and absolute quantification, GPC+PC levels from the anterior cingulate cortex (ACC), caudate and putamen of 16 RC BD-I, 34 non-RC BD-I and 44 healthy controls were assessed. We found significantly elevated GPC+PC levels in ACC, putamen and caudate of RC BD-I patients compared to healthy controls (P

BACKGROUND AND AIMS: Cognitive impairments are one of the primary hallmarks symptoms of bipolar disorder (BD). Whether these deficits are markers of vulnerability or symptoms of the disease is still an open debate. This study used a component-wise gradient (CGB) machine learning algorithm to identify cognitive measures that could accurately differentiate pediatric BD, unaffected offspring of BD parents, and healthy volunteers. METHODS: 59 healthy controls (HC; 11.19±3.15 yo; 30 girls), 119 children and adolescents with BD (13.31±3.02 yo, 52 girls) and 49 unaffected offspring of BD parents (UO; 9.36±3.18 yo; 22 girls) completed the CANTAB cognitive battery. RESULTS: After algorithm training, CGB achieved accuracy of 71.4% and an AUROC of 0.797 in classifying individuals as either BD or non-BD on a dataset held out for validation for testing. The strongest cognitive predictors of BD were measures of affective processing and sustained attention. Measures of cognition did not differentiate between unaffected offspring and HC. CONCLUSIONS: Our findings suggest that alterations in affective processing and sustained attention are markers of BD in pediatric populations. Longitudinal studies should determine whether UO with a cognitive profile similar to that of HC in late childhood or early adolescence are at less or equal risk for mood disorders. Future studies should include relevant cognitive measures for BD such as verbal memory and individuals’ genetic risk scores.

Objective Neuroinflammation has been implicated in the pathophysiology of bipolar disorder. Some evidence shows that nonsteroidal anti-inflammatory drugs (NSAIDs) have promising antidepressant effects. The antioxidant N-acetylcysteine (NAC) may enhance the effects of NSAIDs. No study has, however, tested the adjunctive therapeutic benefits of an NSAID and NAC in bipolar disorder. Methods The sample included 24 medicated patients diagnosed with DSM-IV-TR bipolar disorder who were aged 18-65 years and had a Montgomery-Asberg Depression Rating Scale (MADRS) score ≥ 20. Participants were randomly assigned to receive either aspirin (1,000 mg), NAC (1,000 mg), combined aspirin and NAC (1,000 mg each), or placebo. Data were collected between 2013 and 2017. The primary outcome was a ≥ 50% reduction in MADRS scores. Participants completed mood and global functioning questionnaires. They also underwent blood tests prior to and following 8 and 16 weeks of treatment. A Bayesian analytic method was adopted, and posterior probability distributions were calculated to determine the probability of treatment response. Results Following the first 8-week treatment phase, individuals on treatment with placebo and NAC + aspirin had a similar probability for successful treatment response (about 70%). Following a 16-week treatment period, NAC + aspirin was associated with higher probability of treatment response (67%) compared to placebo (55%), NAC (57%), and aspirin (33%). There was no treatment effect on interleukin-6 and C-reactive protein levels at either 8 or 16 weeks. Conclusions The coadministration of NAC and aspirin during a period of 16 weeks was associated with a reduction in depressive symptoms. The adverse effects were minimal. These preliminary findings may serve as a starting point for future studies assessing the efficacy, tolerability, and safety of anti-inflammatory and antioxidant agents in the treatment of bipolar depression. Trial registration ClinicalTrials.gov identifier: NCT01797575.

Background Previous proton magnetic resonance spectroscopy (1H MRS) studies have reported elevated glycerophosphocholine plus phosphocholine (GPC+PC) in the basal ganglia of patients with bipolar disorders (BD), which implicates an imbalance between synthesis and degradation activity of neuronal and glia membrane phospholipids (MPLs). However, the full extent of altered metabolites of MPLs in subareas within the basal ganglia, such as caudate and putamen, as well as anterior cingulate cortex (ACC) of BD patients is poorly understood. Methods Multi-voxel 1H MRS measurements were acquired in 50 type-one BD (BD-I) and 44 healthy controls (HC) on a 3-T MRI scanner. Four different anatomically defined voxels covering ACC, caudate and putamen were systematically extracted and quantified using LCModel. Group differences in absolute GPC+PC and other metabolites were tested with age and gender as covariates. Results BD-I patients had higher GPC+PC levels in the anterior-dorsal ACC (p = 0.037), caudate (p = 0.005) and putamen (p = 0.004) compared to HC. GPC+PC levels in the caudate were elevated most significantly in currently unmediated BD-I patients (p = 0.022) and were positively correlated with HAM-D scores (r = 0.51, p = 0.005). PCr+Cr and myo-inositol levels were also significantly higher in the caudate head (F(1,45) = 6.010, p = 0.018) of patients compared to HC. NAA and glutamate levels were not significantly different between BD-I and HC in these regions (p > 0.05). Conclusion The increased GPC+PC in BD-I patients may reflect an imbalance in the MPL metabolism. Caudate GPC+PC levels may be a potential biomarker for depressive symptoms in BD.

Background Cognitive impairment is a well-established feature of bipolar disorder (BD). Comorbid BD and substance use leads to poor psychosocial and clinical outcomes. However, knowledge on the neurocognitive functioning of individuals with dual diagnosis is limited. The aim of this study is to assess the cognitive performance of subjects with BD, BD with comorbid alcohol use disorder (AUD), and BD with comorbid illicit substance use disorders (SUD) as compared to healthy individuals. Methods We included 270 inpatients and outpatients with BD and 211 healthy controls. The diagnostic of BD and substance use disorder was assessed using the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders Axis I. Demographic and clinical information were also collected. The cognitive assessment included the Wechsler Test of Adult Reading (WTAR), and a revised version of the California Verbal Learning Test (CVLT) as part of the South Texas Assessment of Neurocognition (STAN). Results The STAN was administered to 134 BD patients (100 female, M±SD: 37.37±12.74 years), 72 BD patients with AUD (40 female, M±SD: 38.42±11.82), 64 BD patients with SUD (39 female, M±SD: 34.50±10.57), and 211 healthy controls with no lifetime history of mental illness and substance use (127 female, M±SD: 34.80±12.57 years). In terms of clinical characteristics, BD+SUD showed a marginally earlier onset of illness compared to BD. Compared to HC, BD performed poorly in the immediate recall and short-delay free tests of the CVLT, while BD patients with AUD and SUD showed significant memory deficits in both the immediate recall and recognition components of the CVLT. There were no differences in memory performance between BD and BD with either AUD or SUD. Conclusions A history of substance use disorders is associated with an earlier onset of BD. BD has marked effects on processes underlying the encoding of new information, while comorbid substance use in BD impairs more specifically the recognition of previously presented information. Future longitudinal studies should evaluate the effects of AUD and SUD on illness progression and therapeutic outcomes.

Background Cognitive deficits have been consistently reported in individuals with bipolar disorder (BD). The cognitive profile of siblings of individuals with BD is, however, less clearly established possibly due to the heterogeneity of neuropsychological measures used in previous studies. The aim of this exploratory study was to assess the cognitive function of siblings of individuals with BD and compare it with that of their first-degree relatives suffering with BD, and healthy controls (HC) using the Cambridge Neuropsychological Test Automated Battery (CANTAB) – a comprehensive and validated computerized cognitive battery. Methods We recruited 23 HC (33.52±10.29 years, 8 males), 27 individuals with BD (34.26±10.19 years, 9 males, 25 BDI, 1BDII and 1 BD-NOS), and 15 of their biologically related siblings (37.47±13.15 years, 4 males). Siblings had no current or lifetime history of mental disorders. Participants performed the CANTAB and completed questionnaires assessing mood and global functioning. Multivariate analyses compared CANTAB measures across the three participant groups. Results Individuals with BD and their siblings were less accurate in a task of sustained attention (Rapid Visual Processing) when compared to HC. Further, individuals with BD displayed pronounced deficits in affective processing (Affective Go/No-Go) compared to HC. There were no cognitive differences between siblings and individuals with BD. After correcting for current depressive symptoms, these results did not reach statistical significance. Conclusions Subthreshold depressive symptoms may be associated with reduced sustained attention in healthy siblings of BD patients. This preliminary result needs to be corroborated by large-scale, longitudinal studies assessing the relationship between cognition and mood in vulnerable individuals.

Background Previous studies have reported that patients with bipolar disorder (BD) present with cognitive impairments during mood episodes as well as euthymic phase. However, it is still unknown whether reported neurocognitive abnormalities can objectively identify individual BD patients from healthy controls (HC). Methods A total of 21 euthymic BD patients and 21 demographically matched HC were included in the current study. Participants performed the computerized Cambridge Neurocognitive Test Automated Battery (CANTAB) to assess cognitive performance. The least absolute shrinkage selection operator (LASSO) machine learning algorithm was implemented to identify neurocognitive signatures to distinguish individual BD patients from HC. Results The LASSO machine learning algorithm identified individual BD patients from HC with an accuracy of 71%, area under receiver operating characteristic curve of 0.7143 and significant at p =0.0053. The LASSO algorithm assigned individual subjects with a probability score (0–healthy, 1–patient). Patients with rapid cycling (RC) were assigned increased probability scores as compared to patients without RC. A multivariate pattern of neurocognitive abnormalities comprising of affective Go/No-go and the Cambridge gambling task was relevant in distinguishing individual patients from HC. Limitations Our study sample was small as we only considered euthymic BD patients and demographically matched HC. Conclusion Neurocognitive abnormalities can distinguish individual euthymic BD patients from HC with relatively high accuracy. In addition, patients with RC had more cognitive impairments compared to patients without RC. The predictive neurocognitive signature identified in the current study can potentially be used to provide individualized clinical inferences on BD patients.

Studies about changes in hippocampal volumes in subjects with bipolar disorder (BD) have been contradictory. Since the number of manic episodes and hospitalization has been associated with brain changes and poor cognitive outcomes among BD patients, we have hypothesized that these variables could clarify this issue. We stratified subjects with BD in early (BD-Early), intermediate (BD-intermediate) and late (BD-Late) stages as a function of number of manic episodes and prior hospitalization. Then, we compared their hippocampal volumes and California Verbal Learning Test-II (CVLT-II) scores with healthy controls (HC) using the general linear model. A total of 173 subjects were included in the study (112 HC, 15 BD-Early, 30 BD-Intermediate, and 16 BD-Late). We found a significant group effect on hippocampus volume (F(3,167) = 3.227, p = 0.024). Post-hoc analysis showed that BD-Late subjects had smaller hippocampus than HC (p = 0.017). BD-Early and BD-Intermediate subjects showed no significant difference in hippocampus volume compared to HC and BD-Late subjects. The CVLT trial 1 to 5 scores were significantly different across the groups (F(3,167) = 6.371, p < 0.001). Post-hoc analysis showed that BD-Intermediate (p = 0.006) and BD-Late (p = 0.017) subjects had worse memory performance during immediate recall than HC, while the performance difference between BD-Early subjects and HC was not significant (p = 0.208). These findings add to the notion that BD is a neuroprogressive disorder with brain changes and cognitive impairment according to prior morbidity (number of manic episodes and hospitalization). Also, they suggest that hippocampus is a brain marker and a potential therapeutic target for patients at late stage.

Background Genetic and environmental factors are implicated in the onset and evolution of pediatric bipolar disorder, and may be associated to structural brain abnormalities. The aim of our study was to assess the impact of the interaction between the Brain-Derived Neurotrophic Factor (BDNF) rs6265 polymorphism and family functioning on hippocampal volumes of children and adolescents with bipolar disorder, and typically-developing controls. Methods: We evaluated the family functioning cohesion subscale using the Family Environment Scale-Revised, genotyped the BDNF rs6265 polymorphism, and performed structural brain imaging in 29 children and adolescents with bipolar disorder, and 22 healthy controls. Results: We did not find significant differences between patients with BD or controls in left or right hippocampus volume ( p =0.44, and p =0.71, respectively). However, we detected a significant interaction between low scores on the cohesion subscale and the presence of the Met allele at BNDF on left hippocampal volume of patients with bipolar disorder ( F =3.4, p =0.043). None of the factors independently (BDNF Val66Met, cohesion scores) was significantly associated with hippocampal volume differences. Limitations: small sample size, cross-sectional study. Conclusions: These results may lead to a better understanding of the impact of the interaction between genes and environment factors on brain structures associated to bipolar disorder and its manifestations.

BACKGROUND Increasing evidence shows that disruption of connectivity has been implicated as a central abnormality in schizophrenia, and the alterations in white matter may be the core basis for this disconnection. Diffusion tensor imaging (DTI) has shown white matter abnormalities in first-episode schizophrenia. However, few studies have examined the correlation between clinical symptoms and white matter abnormalities in drug-naive patients with first-episode schizophrenia. METHOD The white matter fractional anisotropy (FA) values of the whole-brain were determined by using voxel-based DTI in 39 drug-naive patients with first-episode schizophrenia (diagnosed according to DSM-IV) and 30 healthy controls matched for age and gender. The psychopathology of schizophrenia was assessed with the Positive and Negative Syndrome Scale (PANSS). The study was conducted from April 2009 to March 2010. RESULTS The patients showed widespread FA reduction in several brain regions, including corpus callosum, brainstem, internal capsule, cingulate, and cerebellum in patients with first-episode schizophrenia when compared to healthy controls (all P values < .01 after adjusting for gender, age, and education). The correlation analysis showed a significant negative correlation between the FA value in the left cerebellum and positive symptoms (r38 = -0.32, P < .05) and a significant positive correlation between the FA values in the corpus callosum and both the PANSS general psychopathology subscore (r38 = 0.39, P < .01) and the PANSS total score (r38 = 0.33, P < .05). CONCLUSIONS Our results indicate that widespread disruption of white matter integrity occurs in an early stage of schizophrenic onset, suggesting an important role in pathogenesis and symptomatology of schizophrenia.

Accumulating evidence showed that interleukin-2 (IL-2) may be involved in the pathophysiology of schizophrenia. Increased IL-2 levels have been found in the serum of schizophrenia patients with mixed results. In the present study, we assessed serum IL-2 levels in a large group of 160 schizophrenia patients compared to 60 healthy control subjects matched for age and gender. The schizophrenia symptomatology was assessed by the Positive and Negative Syndrome Scale (PANSS), and serum IL-2 levels were measured by sandwich ELISA. The results showed that IL-2 levels were significantly higher in chronic patients with schizophrenia than in healthy control subjects (p

Bipolar disorder (BD) is characterized by biased processing of emotional information. However, little research in this area has been conducted in youth with BD and at-risk individuals. The goal of this study was to determine whether children with BD displayed comparable or more severe manifestations of this bias relative to offspring of parents with BD.The sample (n = 57 children and adolescents) included 18 individuals with BD (age: 13.63 ± 2.99; 8 females), 16 offspring of parents with BD (age: 11.83 ± 2.96; 9 females) and 23 healthy controls (HC) (age: 12.789 ± 3.087; 8 females). All participants performed the Affective Go/No-Go (AGN) and the Rapid Visual Processing (RVP) tasks of the Cambridge Neuropsychological Test Automated Battery (CANTAB).Relative to HC, individuals with BD responded faster to correct trials and committed an elevated number of commission errors across all affective conditions of the AGN task. By contrast, BD offspring showed intact performance accuracy but quicker response times than HC. Post-hoc analyses revealed that this behavioral pattern was observed in BD offspring with mental health problems but not in healthy BD offspring. Overall, mean reaction times and total number of errors in the RVP task were comparable across groups.In line with previous findings, subjects with BD encountered difficulties in processing affective information. The tendency toward faster but accurate responses to affective stimuli observed in BD offspring may be a marker of attentional bias toward affective information and constitute a vulnerability marker for mood disorder.

Previous studies have reported abnormalities of white-matter diffusivity in pediatric bipolar disorder. However, it has not been established whether these abnormalities are able to distinguish individual subjects with pediatric bipolar disorder from healthy controls with a high specificity and sensitivity. Diffusion-weighted imaging scans were acquired from 16 youths diagnosed with DSM-IV bipolar disorder and 16 demographically matched healthy controls. Regional white matter tissue microstructural measurements such as fractional anisotropy, axial diffusivity and radial diffusivity were computed using an atlas-based approach. These measurements were used to `train' a support vector machine (SVM) algorithm to predict new or `unseen' subjects' diagnostic labels. The SVM algorithm predicted individual subjects with specificity = 87.5%, sensitivity = 68.75%, accuracy = 78.12%, positive predictive value = 84.62%, negative predictive value = 73.68%, area under receiver operating characteristic curve (AUROC) = 0.7812 and chi-square p-value = 0.0012. A pattern of reduced regional white matter fractional anisotropy was observed in pediatric bipolar disorder patients. These results suggest that atlas-based diffusion weighted imaging measurements can distinguish individual pediatric bipolar disorder patients from healthy controls. Notably, from a clinical perspective these findings will contribute to the pathophysiological understanding of pediatric bipolar disorder.

Bipolar disorder (BD) has been previously associated with accelerated aging; yet, the mechanisms underlying this association are largely unknown. The epigenetic clock has been increasingly recognized as a valuable aging marker, although its association with other biological clocks in BD patients and high-risk subjects, such as telomere length and mitochondrial DNA (mtDNA) copy number, has never been investigated. We included 22 patients with BD I, 16 siblings of BD patients, and 20 healthy controls in this analysis. DNA was isolated from peripheral blood and interrogated for genome-wide DNA methylation, mtDNA copy number, and telomere length. DNA methylation age (DNAm age) and accelerated aging were calculated using the Horvath age estimation algorithm in blood and in postmortem brain from BD patients and nonpsychiatric controls using publicly available data. Older BD patients presented significantly accelerated epigenetic aging compared to controls, whereas no difference was detected among the younger subjects. Patients showed higher levels of mtDNA copy number, while no difference was found between controls and siblings. mtDNA significantly correlated with epigenetic age acceleration among older subjects, as well and with global functioning in our sample. Telomere length did not show significant differences between groups, nor did it correlate with epigenetic aging or mtDNA copy number. These results suggest that BD may involve an accelerated epigenetic aging, which might represent a novel target for treating BD and subjects at risk. In particular, our results suggest a complex interplay between biological clocks to determine the accelerated aging and its consequences in BD.

The hippocampus has been implicated in various mood disorders, with global volume deficits consistently found in patient populations. The hippocampus, however, consists of anatomically distinct subfields, and examination of specific subfield differences may elucidate the possible molecular mechanisms behind psychiatric pathologies. Indeed, adult studies have reported smaller hippocampal subfield volumes in regions within the cornu ammonis (CA1 and CA4), dentate gyrus (DG), and hippocampal tails in both patients with Major Depressive Disorder (MDD) and Bipolar Disorder (BD) compared to healthy controls. Subfield differences in pediatric patients with mood disorders, on the other hand, have not been extensively investigated. In the current study, magnetic resonance imaging scans were acquired for 141 children and adolescents between the ages of eight and eighteen (57 with BD, 30 with MDD, and 54 healthy controls). An automated segmentation method was then used to assess differences in hippocampal subfield volumes. Children and adolescents with BD were found to have significantly smaller volumes in the right CA1, CA4, and right subiculum, as well as the bilateral granule cell layer (GCL), molecular layer (ML), and hippocampal tails. The volume of the right subiculum in BD patients was also found to be negatively correlated with illness duration. Overall, the findings from this cross-sectional study provide evidence for specific hippocampal subfield volume differences in children and adolescents with BD compared to healthy controls and suggest progressive reductions with increased illness duration.

Background Impulsivity is a common feature shared by bipolar disorder (BD) and substance use disorder (SUD). SUD and recurrent mood episodes are considered to be risk factors for poor outcome in BD. However, the association between impulsivity, illness chronicity and SUD in BD remains unexplored. Methods 103 BD patients with and without a lifetime history of SUD (36.82±11.34 years, 40 males) were recruited. Participants completed the SCID interview and were administered measures of impulsivity including the Barratt Impulsivity Scale (BIS) and selected tests of the Cambridge Neuropsychological Test Automated Battery (CANTAB). Hierarchical regression analyses explored the relationship between illness chronicity, SUD, and impulsivity. Results Variance in the BIS, number of false alarms on the Rapid Visual Processing task and other impulsivity indicators of the Cambridge Gambling Task (CGT) was not explained by the chosen variables. Only an increased number of commission errors in the negative condition of the Affective Go/No Go task was significantly associated with illness chronicity. Furthermore there was a trend suggesting a relationship between a lifetime history of SUD and increased propensity to risk-taking during the CGT. Limitations Potential limitations include medication and patients׳ remission status from SUD. Conclusions Contrary to our expectations impulsivity was generally not predicted by indicators of illness chronicity or SUD. While impulsivity could still be a marker of BD that is present before the onset of the disorder, the link between the number of mood episodes and specific indicators of impulsivity may be related to mechanisms of neuroprogression.

Neurodegenerative processes may be involved in the pathogenesis of schizophrenia. Brain-derived neurotrophic factor (BDNF), the most widely distributed neurotrophin and oxidative stress (OS) may be critical for several pathological manifestations of neurodegenerative disorders. Accumulating evidence suggests that both BDNF and OS may be involved in the pathophysiology of schizophrenia. However, the possible interaction between BDNF and OS has been under-investigated. Serum BDNF, plasma malondialdehyde (MDA) levels and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activities were analyzed using established procedures in 164 chronic medicated schizophrenia and 50 healthy controls. Schizophrenic symptoms were assessed by the Positive and Negative Syndrome Scale (PANSS) with cognitive and depressive factors derived from the five factor model of the PANSS. Compared to the control group, the patients exhibited a significant decrease in BDNF levels, in the activities of SOD and GSH-Px but a significant increase in MDA levels. In patients, but not in controls, we observed a significant negative correlation between BDNF and SOD. Furthermore, the interaction between BDNF and CAT was associated with the PANSS cognitive factor, and the interaction between BDNF and GSH-Px with the PANSS depressive factor. Both decreased BDNF levels and OS may be implicated in the pathophysiology of chronic schizophrenia. Their inverse association only in the schizophrenia group may reflect a pathological mechanism involving an interaction of oxidative damage and neurotrophin dysfunction. Moreover, OS may interact with the BDNF system to influence the clinical symptoms and cognitive impairment in schizophrenia, which is line with the neurodevelopmental hypothesis of schizophrenia.

Some recent studies show an association between a functional polymorphism of BDNF gene (Val66Met) and the susceptibility to nicotine dependence and we hypothesized that this polymorphism was associated with smoking in both schizophrenia patients and healthy controls. The BDNF Val66Met gene polymorphism was genotyped in 690 chronic male schizophrenia patients (smoker/nonsmoker = 522/169) and 628 male controls (smoker/nonsmoker = 322/306) using a case-control design. Nicotine dependence (ND) was assessed by the cigarettes smoked per day (CPD), the Heaviness of Smoking Index (HSI), and the Fagerstrom Test for ND (FTND). Patients also were rated on the Positive and Negative Syndrome Scale (PANSS). The results showed no significant differences in BDNF Val66Met genotype and allele distributions between the patients and healthy controls or between smokers and nonsmokers in either patients or healthy controls alone. In patient groups, however, the smokers with the Met allele had significantly higher HSI scores (Met/Met: 2.8 ± 1.7 vs. Met/Val: 2.2 ± 1.7 vs. Val/Val: 2.0 ± 1.6, p < 0.01) and a trend toward a significantly higher FTND score (p = 0.09) than those with the Val/Val genotype. In addition, the smokers showed significantly lower PANSS negative symptom and total scores, longer duration of illness and more hospitalizations (all p < 0.05). In the control group, the smokers with the Met allele started smoking significantly earlier than those with the Val/Val genotype (both p < 0.05). These results suggest that the BDNF Val66Met polymorphism may affect a smoker's response to nicotine in both schizophrenia and healthy controls from a Chinese Han population, but with differential effects in different aspects of smoking behaviors.

Bipolar disorder (BD) is a common disorder with high reoccurrence rate in general population. It is critical to have objective biomarkers to identify BD patients at an individual level. Neurocognitive signatures including affective Go/No-go task and Cambridge Gambling task showed the potential to distinguish BD patients from health controls as well as identify individual siblings of BD patients. Moreover, these neurocognitive signatures showed the ability to be replicated at two independent cohorts which indicates the possibility for generalization. Future studies will examine the possibility of combining neurocognitive data with other biological data to develop more accurate signatures. Electronic supplementary material The online version of this article (doi:10.1186/s40345-017-0101-9) contains supplementary material, which is available to authorized users.

Bipolar disorder (BD) is a common disorder with high reoccurrence rate in general population. It is critical to have objective biomarkers to identify BD patients at an individual level. Neurocognitive signatures including affective Go/No-go task and Cambridge Gambling task showed the potential to distinguish BD patients from health controls as well as identify individual siblings of BD patients. Moreover, these neurocognitive signatures showed the ability to be replicated at two independent cohorts which indicates the possibility for generalization. Future studies will examine the possibility of combining neurocognitive data with other biological data to develop more accurate signatures.

Objective: Increased impulsivity seems to be present across all phases of bipolar disorder (BD). Impulsivity may therefore represent an endophenotype for BD, if it is also found among normal individuals at high genetic risk for mood disorders. In this study, we assessed impulsivity across four different groups of children and adolescents: patients with BD, major depressive disorder (MDD) patients, unaffected offspring of bipolar parents (UO), and healthy controls (HC). Subjects and Methods: 52 patients with BD, 31 with MDD, 20 UO, and 45 HC completed the Barratt Impulsiveness Scale (BIS-11), an instrument designed to measure trait impulsivity. Results: UO displayed significantly higher total BIS-11 impulsivity scores than HC (p = 0.02) but lower scores than BD patients (F = 27.12, p

Epidemiological studies have previously established that pediatric bipolar disorder (PBD) has a prevalence rate of approximately 1.0–1.5% in the general population (1-3). Family, twin, and adoption studies have also reported that PBD is highly heritable, with families of bipolar probands having an elevated risk of developing the disorder (4, 5). In addition, nearly one-third of patients with PBD attempt suicide at least once (6), with previous reports indicating that early onset bipolar disorder appears to follow a more severe course with poorer long-term prognosis as compared to late onset bipolar disorder (7, 8). Overall, these facts translate to elevated treatment costs and a high socio-economic burden which underscores the need to elucidate the pathophysiological mechanism of the disorder (6). Converging evidence from both structural and functional neuroimaging studies has consistently implicated the dysfunction of the anterior-limbic system in the pathophysiology of PBD (3, 9-13). The anterior-limbic system consists of heavily interconnected regions which include the amygdala, prefrontal cortex, thalamus, and striatum, which are involved in mood, cognition, and emotion regulation (3, 9, 14-18). Interestingly, experiments from both functional neuroimaging and lesion studies have also established that the amygdala is principally responsible for emotion modulation, such as recognizing fear and anger from facial expressions (3, 10, 19-24). Remarkably, there is also consensus from multiple group-level structural neuroimaging studies on the existence of volumetric reductions in the amygdala of patients with PBD as compared to their typically developing peers (9, 11-13, 17, 25-28). Indeed, this is by far the most replicated finding in PBD structural neuroimaging studies (29). This finding is further highlighted in these subsequent reviews and meta-analyses (3, 10, 30). However, despite these noteworthy advancements in our understanding of PBD, diagnosis, prognosis, and treatment planning still remain subjective—based on signs and symptoms and without any pathognomonic tests. Markedly, an important first step in achieving the goal of deploying pathognomonic tests in diagnosis and prognosis of PBD is being able to predict subjects with PBD at an individual subject level. A majority of previous studies have only been able to identify average group-level neuroanatomical differences between subjects with PBD and healthy controls. As a result, in this study we set out to investigate whether neuroanatomical signatures of the amygdala from T1-weighted neuroimaging scans can objectively predict PBD diagnosis at an individual subject level. Multivariate pattern analysis techniques also known as machine learning techniques have recently been applied in clinical neuroimaging studies to make predictions at an individual subject level with success (22, 31-37). In general, these techniques are implemented in three key stages. First, neuroimaging scan data from several subjects with corresponding diagnostic labels (e.g., 1 = PBD and 2 = healthy controls) are used to train or develop a statistical model. Second, the accuracy of the learnt model is evaluated using novel data not used during the training stage. Third, the model's ability to generalize from novel or unseen data is reported using several statistical measurements such as diagnostic accuracy, specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV), and a receiver operating characteristic (ROC) curve. Detailed discussions of these methods with respect to clinical neuroimaging data are given elsewhere (22, 31-35, 38, 39). However, in this study, the Elastic Net pattern analysis method (40, 41) was ‘trained’ to make novel predictions on individual subjects. In summary, the main objective of this study was to examine the utility of voxel-based gray matter values from the amygdala to objectively predict individual subjects with PBD or healthy controls. This hypothesis was primarily motivated by the emerging consensus from multiple neuroimaging studies on volumetric reductions in the amygdala of patients with PBD as compared to healthy controls (9, 11-13, 17, 25, 26, 42) as summarized in Table 1. Table 1 A summary of previous studies highlighting structural neuroanatomical abnormalities in the amygdala of patients with pediatric bipolar disorder

Objectives To evaluate temperament and character traits using the Junior Temperament and Character Inventory (JTCI) in children and adolescents with major depressive disorder (MDD) in comparison with healthy control subjects (HC), and to verify if comorbidity with disruptive behavioral disorders and being currently depressed influence JTCI scores. Methods A case–control study comprising 41 MDD children/adolescents matched to 40 HC by gender and age (8–17 years). All participants were assessed diagnostically with the Kiddie Schedule for Affective Disorders and Schizophrenia – Present and Lifetime (K-SADS-PL). Temperament and character traits were measured with the parent and child versions of JTCI, and depression was evaluated with the Children's Depression Rating Scale (CDRS). Results According to child and parent data, MDD subjects had significantly higher scores on harm avoidance and novelty seeking, and lower scores on reward dependence, persistence, self-directedness and cooperativeness compared with HC. According to parent data only, MDD subjects significantly differed from HC on self-transcendence (lower spirituality scores and higher fantasy scores). Comorbidity with disruptive behavioral disorders exerted influence on almost all dimensions, in general increasing the mean differences between MDD and HC subjects. Also, being currently depressed did not influence the results, except for reward dependence according to parent data. Limitations The cross-sectional nature of the study and its limited sample size. Conclusions MDD children/adolescents have a different temperament and character profile compared to HC subjects. This study supports previous findings of trait-like characteristics of harm avoidance and self-directedness.

Bipolar disorder (BD) is commonly associated with increased impulsivity, particularly during manic and depressed episodes (1, 2), and unipolar depressive disorder (UP) is also associated with increased impulsivity during depressive episodes (3). In BD, impulsivity also remains elevated during euthymic phases, suggesting that it is a trait-like personality characteristic (4). Increased impulsivity adversely affects the illness course of BD and UP by increasing suicide risk (1, 3, 5, 6) and mood instability (7). In BD, elevated impulsivity during euthymic periods contributes to disruptive behaviors such as reckless driving (8), substance abuse disorder (9), and poor adherence to treatment (10). However, there is a lack of studies assessing impulsivity in euthymic UP patients, so it is not known whether impulsivity is related to poor illness course and risk of substance abuse as with BD. Increased impulsivity in BD and UP during illness episodes as well as in euthymic states supports the suggestion that impulsivity is related to mood disorders in general (4, 7). If this is confirmed, then therapies targeting impulsivity could represent novel interventions for mental disorders with impulsivity at their core, as suggested by Pattij and Vanderschuren (11). In this study, we compared questionnaire-measured impulsivity in euthymic BD and UP patients, healthy controls (HC), and a group of unaffected relatives (NAR) of BD patients. The NAR were included because impulsivity may be an inherited trait that could predispose vulnerable individuals to affective disorders in general (12). We also compared impulsivity in patients with and without history of suicide attempts and substance abuse to determine whether impulsivity during the euthymic interval predicts these outcomes. We hypothesized that: (i) euthymic BD and UP subjects have higher impulsivity than NAR and HC; (ii) NAR have higher impulsivity than HC; and (iii) euthymic BD and UP patients with past suicide attempts and substance abuse history have higher impulsivity than BD and UP subjects without such histories.

Background Bipolar disorder (BD) is characterized by affective processing bias and variations in personality traits. It is still unknown whether these features are linked to the same structural brain alterations. The aim of this study was to investigate relationships between specific personality traits, white matter (WM) properties, and affective processing in BD and HC. Methods 24 healthy controls (HC) and 38 adults with BDI (HC: 29.47 ± 2.23 years, 15 females; BDI: 32.44 ± 1.84 years, 20 females) completed clinical scales and the Big Five Inventory. They were also administered the Affective Go/No-Go (AGN) and the Rapid Visual Processing (RVP) tasks of the Cambridge Neuropsychological Test Automated Battery. Diffusion Tensor Imaging (DTI) assessed the microstructure of WM tracts. Results In BDI measures of WM properties were reduced across all major brain white matter tracts. As expected, individuals with BDI reported greater neuroticism, lower agreeableness and conscientiousness, and made a greater number of errors in response to affective stimuli in the AGN task compared to HC. High neuroticism scores were associated with faster AGN latency, and overall reduced AGN accuracy in both HC and BDI. Elevated FA values were associated with reduced neuroticism and increased cognitive processing in HC but not in BDI. Conclusions Our findings showed important potential links between personality, affective processing and WM integrity in BD. In the future therapeutic interventions for BD using brain stimulation protocols might benefit from the use of DTI to target pathways underlying abnormal affective processing.

The subgenual prefrontal cortex (SGPFC) is an important brain region involved in emotional regulation and reward mechanisms. Volumetric abnormalities in this region have been identified in adults with bipolar disorder but thus far not in pediatric cases. We examined the volume of this brain region in subjects with pediatric bipolar disorder (PBD) and compared them to healthy controls.Fifty one children and adolescents (mean age ± SD; 13.2 ± 2.9 y) with DSM-IV PBD and 41 (mean age ± SD; 13.7 ± 2.7 y) healthy comparison subjects (HC) underwent 1.5 T structural magnetic resonance imaging (MRI) brain scans. We traced the SGPFC manually and compared SGPFC gray matter volumes using analysis of covariance with age, gender, and intracranial volume as covariates. We also examined the relationship of family history of affective disorders and medication status to SGPFC volumes.SGPFC volumes were not significantly different in PBD and HC subjects. However, exploratory analysis showed PBD subjects who had one or more first degree relatives with mood disorders (n = 33) had significantly smaller left hemisphere SGPFC compared to HC (p = 0.03 Sidak corrected). Current usage of a mood stabilizer was significantly associated with larger right SGPFC volume in PBD (F = 4.82, df = 1/41, p = 0.03).Subjects with PBD and a close family history of mood disorders may have smaller left SGPFC volumes than HC. Mood stabilizing medication may also impact SGPFC size and could have masked more subtle abnormalities overall.