Prediction of emergency department revisits among child and youth mental health outpatients using deep learning techniques

BACKGROUND

The proportion of Canadian youth seeking mental health support from an emergency department (ED) has risen in recent years. As EDs typically address urgent mental health crises, revisiting an ED may represent unmet mental health needs. Accurate ED revisit prediction could aid early intervention and ensure efficient healthcare resource allocation. We examine the potential increased accuracy and performance of graph neural network (GNN) machine learning models compared to recurrent neural network (RNN), and baseline conventional machine learning and regression models for predicting ED revisit in electronic health record (EHR) data.

METHODS

This study used EHR data for children and youth aged 4-17 seeking services at McMaster Children's Hospital's Child and Youth Mental Health Program outpatient service to develop and evaluate GNN and RNN models to predict whether a child/youth with an ED visit had an ED revisit within 30 days. GNN and RNN models were developed and compared against conventional baseline models. Model performance for GNN, RNN, XGBoost, decision tree and logistic regression models was evaluated using F1 scores.

RESULTS

The GNN model outperformed the RNN model by an F1-score increase of 0.0511 and the best performing conventional machine learning model by an F1-score increase of 0.0470. Precision, recall, receiver operating characteristic (ROC) curves, and positive and negative predictive values showed that the GNN model performed the best, and the RNN model performed similarly to the XGBoost model. Performance increases were most noticeable for recall and negative predictive value than for precision and positive predictive value.

CONCLUSIONS

This study demonstrates the improved accuracy and potential utility of GNN models in predicting ED revisits among children and youth, although model performance may not be sufficient for clinical implementation. Given the improvements in recall and negative predictive value, GNN models should be further explored to develop algorithms that can inform clinical decision-making in ways that facilitate targeted interventions, optimize resource allocation, and improve outcomes for children and youth.

Serotonin transporter (5-HTT) gene network moderates the impact of prenatal maternal adversity on orbitofrontal cortical thickness in middle childhood

In utero, the developing brain is highly susceptible to the environment. For example, adverse maternal experiences during the prenatal period are associated with outcomes such as altered neurodevelopment and emotion dysregulation. Yet, the underlying biological mechanisms remain unclear. Here, we investigate whether the function of a network of genes co-expressed with the serotonin transporter in the amygdala moderates the impact of prenatal maternal adversity on the structure of the orbitofrontal cortex (OFC) in middle childhood and/or the degree of temperamental inhibition exhibited in toddlerhood. T1-weighted structural MRI scans were acquired from children aged 6-12 years. A cumulative maternal adversity score was used to conceptualize prenatal adversity and a co-expression based polygenic risk score (ePRS) was generated. Behavioural inhibition at 18 months was assessed using the Early Childhood Behaviour Questionnaire (ECBQ). Our results indicate that in the presence of a low functioning serotonin transporter gene network in the amygdala, higher levels of prenatal adversity are associated with greater right OFC thickness at 6-12 years old. The interaction also predicts temperamental inhibition at 18 months. Ultimately, we identified important biological processes and structural modifications that may underlie the link between early adversity and future deviations in cognitive, behavioural, and emotional development.

Examining resting-state network connectivity in children exposed to perinatal maternal adversity using anatomically weighted functional connectivity (awFC) analyses; A preliminary report

Introduction

Environmental perturbations during critical periods can have pervasive, organizational effects on neurodevelopment. To date, the literature examining the long-term impact of early life adversity has largely investigated structural and functional imaging data outcomes independently. However, emerging research points to a relationship between functional connectivity and the brain’s underlying structural architecture. For instance, functional connectivity can be mediated by the presence of direct or indirect anatomical pathways. Such evidence warrants the use of structural and functional imaging in tandem to study network maturation. Accordingly, this study examines the impact of poor maternal mental health and socioeconomic context during the perinatal period on network connectivity in middle childhood using an anatomically weighted functional connectivity (awFC) approach. awFC is a statistical model that identifies neural networks by incorporating information from both structural and functional imaging data.

Methods

Resting-state fMRI and DTI scans were acquired from children aged 7–9 years old.

Results

Our results indicate that maternal adversity during the perinatal period can affect offspring’s resting-state network connectivity during middle childhood. Specifically, in comparison to controls, children of mothers who had poor perinatal maternal mental health and/or low socioeconomic status exhibited greater awFC in the ventral attention network.

Discussion

These group differences were discussed in terms of the role this network plays in attention processing and maturational changes that may accompany the consolidation of a more adult-like functional cortical organization. Furthermore, our results suggest that there is value in using an awFC approach as it may be more sensitive in highlighting connectivity differences in developmental networks associated with higher-order cognitive and emotional processing, as compared to stand-alone FC or SC analyses.

Gray matter volume drives the brain age gap in schizophrenia: a SHAP study

Neuroimaging-based brain age is a biomarker that is generated by machine learning (ML) predictions. The brain age gap (BAG) is typically defined as the difference between the predicted brain age and chronological age. Studies have consistently reported a positive BAG in individuals with schizophrenia (SCZ). However, there is little understanding of which specific factors drive the ML-based brain age predictions, leading to limited biological interpretations of the BAG. We gathered data from three publicly available databases - COBRE, MCIC, and UCLA - and an additional dataset (TOPSY) of early-stage schizophrenia (82.5% untreated first-episode sample) and calculated brain age with pre-trained gradient-boosted trees. Then, we applied SHapley Additive Explanations (SHAP) to identify which brain features influence brain age predictions. We investigated the interaction between the SHAP score for each feature and group as a function of the BAG. These analyses identified total gray matter volume (group × SHAP interaction term β = 1.71 [0.53; 3.23]; p_corr < 0.03) as the feature that influences the BAG observed in SCZ among the brain features that are most predictive of brain age. Other brain features also presented differences in SHAP values between SCZ and HC, but they were not significantly associated with the BAG. We compared the findings with a non-psychotic depression dataset (CAN-BIND), where the interaction was not significant. This study has important implications for the understanding of brain age prediction models and the BAG in SCZ and, potentially, in other psychiatric disorders.

A detailed manual segmentation procedure for the hypothalamus for 3T T1-weighted MRI

The hypothalamus is a small grey matter structure which plays a crucial role in many physiological functions. Some studies have found an association between hypothalamic volume and psychopathology, which stresses the need for a standardized method to maximize segmentation accuracy. Here, we provide a detailed step-by-step method outlining the procedures to manually segment the hypothalamus using anatomical T1w images from 3T scanners, which many neuroimaging studies collect as a standard anatomical reference image. We compared volumes generated by manual segmentation and those generated by an automatic algorithm, observing a significant difference between automatically and manually segmented hypothalamus volumes on both sides (left: U = 222842, p-value < 2.2e-16; right: U = 218520, p- value < 2.2e-16).•Significant difference exists between existing automatic segmentation methods and the manual segmentation procedure.•We discuss potential drift effects, segmentation quality issues, and suggestions on how to mitigate them.•We demonstrate that the present manual segmentation procedure using standard T1-weighted MRI may be significantly more accurate than automatic segmentation outputs.

Accelerated brain aging in major depressive disorder and antidepressant treatment response: A CAN-BIND report

OBJECTIVES

Previous studies suggest that major depressive disorder (MDD) may be associated with volumetric indications of accelerated brain aging. This study investigated neuroanatomical signs of accelerated aging in MDD and evaluated whether a brain age gap is associated with antidepressant response.

METHODS

Individuals in a major depressive episode received escitalopram treatment (10-20 mg/d) for 8 weeks. Depression severity was assessed at baseline and at weeks 8 and 16 using the Montgomery-Asberg Depression Rating Scale (MADRS). Response to treatment was characterized by a significant reduction in the MADRS (≥50%). Nonresponders received adjunctive aripiprazole treatment (2-10 mg/d) for a further 8 weeks. The brain-predicted age difference (brain-PAD) at baseline was determined using machine learning methods trained on 3377 healthy individuals from seven publicly available datasets. The model used features from all brain regions extracted from structural magnetic resonance imaging data.

RESULTS

Brain-PAD was significantly higher in older MDD participants compared to younger MDD participants [t(147.35) = -2.35, p < 0.03]. BMI was significantly associated with brain-PAD in the MDD group [r(155) = 0.19, p < 0.03]. Response to treatment was not significantly associated with brain-PAD.

CONCLUSION

We found an elevated brain age gap in older individuals with MDD. Brain-PAD was not associated with overall treatment response to escitalopram monotherapy or escitalopram plus adjunctive aripiprazole.

Hypothalamus volume and DNA methylation of stress axis genes in major depressive disorder: A CAN-BIND study report

Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis is considered one of the mechanisms underlying the development of major depressive disorder (MDD), but the exact nature of this dysfunction is unknown. We investigated the relationship between hypothalamus volume (HV) and blood-derived DNA methylation in MDD. We obtained brain MRI, clinical and molecular data from 181 unmedicated MDD and 90 healthy control (HC) participants. MDD participants received a 16-week standardized antidepressant treatment protocol, as part of the first Canadian Biomarker Integration Network in Depression (CAN-BIND) study. We collected bilateral HV measures via manual segmentation by two independent raters. DNA methylation and RNA sequencing were performed for three key HPA axis-regulating genes coding for the corticotropin-binding protein (CRHBP), glucocorticoid receptor (NR3C1) and FK506 binding protein 5 (FKBP5). We used elastic net regression to perform variable selection and assess predictive ability of methylation variables on HV. Left HV was negatively associated with duration of current episode (ρ = -0.17, p = 0.035). We did not observe significant differences in HV between MDD and HC or any associations between HV and treatment response at weeks 8 or 16, overall depression severity, illness duration or childhood maltreatment. We also did not observe any differentially methylated CpG sites between MDD and HC groups. After assessing functionality by correlating methylation levels with RNA expression of the respective genes, we observed that the number of functionally relevant CpG sites differed between MDD and HC groups in FKBP5 (χ² = 77.25, p < 0.0001) and NR3C1 (χ² = 7.29, p = 0.007). Cross-referencing functionally relevant CpG sites to those that were highly ranked in predicting HV in elastic net modeling identified one site from FKBP5 (cg03591753) and one from NR3C1 (cg20728768) within the MDD group. Stronger associations between DNA methylation, gene expression and HV in MDD suggest a novel putative molecular pathway of stress-related sensitivity in depression. Future studies should consider utilizing the epigenome and ultra-high field MR data which would allow the investigation of HV sub-fields.

Examining the predictive association of irritability with borderline personality disorder in a clinical sample of female adolescents

OBJECTIVES

Borderline personality disorder (BPD) is a disorder associated with emotion dysregulation and is common in clinical samples of adolescents. The identification and delineation of BPD from other disorders is important, yet methods for effectively screening for BPD are lacking. Here, we examine whether irritability can be used as a screening item for BPD in adolescents at risk for the disorder.

METHODS

We assessed Diagnostic Interview for Borderline-Revised and Development of Well-Being Assessment scores in a clinical sample of female adolescents ages 12-17 (n = 78) to identify BPD and group cases into 'irritable' and 'non-irritable' mood types, respectively. We then examined the prevalence of irritability and its predictive association with BPD.

RESULTS

The prevalence of BPD was 26% (n = 20). There was a significant association between irritable mood and BPD, specifically (χ² (1) = 17.740, p < 0.001). Irritability was endorsed in all (n = 20) BPD cases (sensitivity: 100%), while in non-BPD cases (n = 58), irritability was endorsed in 27 (specificity: 53%; positive predictive value: 0.33; and negative predictive value: 1.0).

CONCLUSION

Irritability is a highly sensitive screening item for BPD in adolescents. The absence of irritability in an adolescent may be an important clinical tool to rule out BPD. © 2020 John Wiley & Sons, Ltd.

An investigation of cortical thickness and antidepressant response in major depressive disorder: A CAN-BIND study report

Major depressive disorder (MDD) is considered a highly heterogeneous clinical and neurobiological mental disorder. We employed a novel layered treatment design to investigate whether cortical thickness features at baseline differentiated treatment responders from non-responders after 8 and 16 weeks of a standardized sequential antidepressant treatment. Secondary analyses examined baseline differences between MDD and controls as a replication analysis and longitudinal changes in thickness after 8 weeks of escitalopram treatment. 181 MDD and 95 healthy comparison (HC) participants were studied. After 8 weeks of escitalopram treatment (10-20 mg/d, flexible dosage), responders (>50% decrease in Montgomery-Åsberg Depression Scale score) were continued on escitalopram; non-responders received adjunctive aripiprazole (2-10 mg/d, flexible dosage). MDD participants were classified into subgroups according to their response profiles at weeks 8 and 16. Baseline group differences in cortical thickness were analyzed with FreeSurfer between HC and MDD groups as well as between response groups. Two-stage longitudinal processing was used to investigate 8-week escitalopram treatment-related changes in cortical thickness. Compared to HC, the MDD group exhibited thinner cortex in the left rostral middle frontal cortex [MNI(X,Y,Z=-29,9,54.5,-7.7); CWP=0.0002]. No baseline differences in cortical thickness were observed between responders and non-responders based on week-8 or week-16 response profile. No changes in cortical thickness was observed after 8 weeks of escitalopram monotherapy. In a two-step 16-week sequential clinical trial we found that baseline cortical thickness does not appear to be associated to clinical response to pharmacotherapy at 8 or 16 weeks.

Association of functioning and quality of life with objective and subjective measures of sleep and biological rhythms in major depressive and bipolar disorder

OBJECTIVE

Disruptions in biological rhythms and sleep are a core aspect of mood disorders, with sleep and rhythm changes frequently occurring prior to and during mood episodes. Wrist-worn actigraphs are increasingly utilized to measure ambulatory activity rhythm and sleep patterns.

METHODS

A comprehensive study using subjective and objective measures of sleep and biological rhythms was conducted in 111 participants (40 healthy volunteers [HC], 38 with major depressive disorder [MDD] and 33 with bipolar disorder [BD]). Participants completed 15-day actigraphy and first-morning urine samples to measure 6-sulfatoxymelatonin levels. Sleep and biological rhythm questionnaires were administered: Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN), Munich Chronotype Questionnaire (MCTQ), Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). Actigraph data were analyzed for sleep and daily activity rhythms, light exposure and likelihood of transitioning between rest and activity states.

RESULTS

Mood groups had worse subjective sleep quality (PSQI) and biological rhythm disruption (BRIAN) and higher objective mean nighttime activity than controls. Participants with BD had longer total sleep time, higher circadian quotient and lower 6-sulfatoxymelatonin levels than HC group. The MDD group had longer sleep onset latency and higher daytime probability of transitioning from rest to activity than HCs. Mood groups displayed later mean timing of light exposure. Multiple linear regression analysis with BRIAN scores, circadian quotient, mean nighttime activity during rest and daytime probability of transitioning from activity to rest explained 43% of variance in quality-of-life scores. BRIAN scores, total sleep time and probability of transitioning from activity to rest explained 52% of variance in functioning (all p < 0.05).

CONCLUSIONS

Disruption in biological rhythms is associated with poorer functioning and quality of life in bipolar and MDD. Investigating biological rhythms and sleep using actigraphy variables, urinary 6-sulfatoxymelatonin and subjective measures provide evidence of widespread sleep and circadian system disruptions in mood disorders.

Impact of a structured, group-based running programme on clinical, cognitive and social function in youth and adults with complex mood disorders: a 12-week pilot study

Background

Individuals with mood disorders often report lingering health-related quality of life (HRQOL) and social and cognitive impairments even after mood symptoms have improved. Exercise programmes improve mood symptoms in patients, but whether exercise improves functional outcomes in patients with difficult-to-treat mood disorders remains unknown.

Design

We evaluated the impact of a 12-week structured running programme on cognitive, social and quality-of-life outcomes in participants with difficult-to-treat mood disorders.

Methods

In a prospective, open-label study, patients referred to the St Joseph’s Healthcare Hamilton Team Unbreakable running programme for youth and adults with mood disorders completed a comprehensive assessment battery before and after the 12-week exercise intervention.

Results

We collected preintervention and postintervention data from 18 participants who improved on the general health, vitality, role of emotions, social functioning and mental health (all p≤0.01) HRQOL subscales. Performance improved on cognitive tests that assessed working memory and processing speed (p≤0.04); there were no improvements in complex executive functioning tasks. Regression analyses indicated that younger age, shorter illness duration and reduced bodily pain predicted social and cognitive outcomes.

Conclusion

Participation in a group-based, structured running programme was associated with improved HRQOL and social and cognitive function.

Impact of maternal adverse childhood experiences on child socioemotional function in rural Kenya: Mediating role of maternal mental health

Mothers in low- and middle-income countries (LMIC) suffer heightened vulnerability for adverse childhood experiences (ACEs), which is exacerbated by the multitude of risk factors associated with poverty and may lead to increased risk of psychiatric disorder. The constellation of complex, co-occurring biological, environmental, social, economic and psychological risk factors are in turn transmitted to her child, conferring vulnerability for adverse development. This study examines the association between maternal intra- and extra-familial ACEs, maternal education and the mental health of her child, mediated by maternal mental health. Mother-child dyads (n = 121) in Machakos, Kenya were examined cross-sectionally using self-report measures of ACEs, maternal mental health and child internalizing and externalizing mental health problems. The four models proposed to examine the relationship between intra- and extra-familial maternal ACEs and child internalizing and externalizing problems demonstrated indirect pathways through maternal mental health. These effects were found to be conditional on levels of maternal education, which served as a protective factor at lower levels of maternal ACEs. These models demonstrate how the impact of ACEs persists across the lifespan resulting in a negative impact on maternal mental health and conferring further risk to subsequent generations. Elucidating the association between ACEs and subsequent intergenerational sequelae, especially in LMIC where risk is heightened, may improve targeted caregiver mental health programs for prevention and intervention.

Symptomatic and Functional Outcomes and Early Prediction of Response to Escitalopram Monotherapy and Sequential Adjunctive Aripiprazole Therapy in Patients With Major Depressive Disorder: A CAN-BIND-1 Report

OBJECTIVE

To report the symptomatic and functional outcomes in patients with major depressive disorder (MDD) during a 2-phase treatment trial and to estimate the value of early improvement after 2 weeks in predicting clinical response to escitalopram and subsequently to adjunctive treatment with aripiprazole.

METHODS

Participants with MDD (N = 211) identified with the Montgomery-Asberg Depression Rating Scale (MADRS) and confirmed with the Mini-International Neuropsychiatric Interview were recruited from 6 outpatient centers across Canada (August 2013 through December 2016) and treated with open-label escitalopram (10-20 mg) for 8 weeks (Phase 1). Clinical and functional outcomes were evaluated using the MADRS, Quick Inventory of Depressive Symptomatology-Self-Rated (QIDS-SR), Sheehan Disability Scale (SDS), and Lam Employment Absence and Productivity Scale (LEAPS). Participants were evaluated at 8 and 16 weeks for clinical and functional response and remission. Phase 1 responders continued escitalopram while nonresponders received adjunctive aripiprazole (2-10 mg) for a further 8 weeks (Phase 2).

RESULTS

After Phase 1, MADRS response (≥ 50% decrease from baseline) and remission (score ≤ 10) were, respectively, 47% and 31%, and SDS response (score ≤ 12) and remission (score ≤ 6) were, respectively, 53% and 24%. Response to escitalopram was maintained in 91% of participants at week 16, while 61% of the adjunctive aripiprazole group achieved MADRS response during Phase 2. Response and remission rates with the QIDS-SR were lower than with the MADRS. The LEAPS demonstrated significant occupational improvement (P < .05). Early symptomatic improvement predicted outcomes with modest accuracy.

CONCLUSIONS

This study demonstrates comparable symptomatic and functional outcomes to those of other large practical-design studies. There was a high response rate with the adjunctive use of aripiprazole in escitalopram nonresponders. Given the limited value of early clinical improvement to predict outcome, integration of clinical and biological markers deserves further exploration.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01655706.

Association of intracortical myelin and cognitive function in bipolar I disorder

OBJECTIVE

Although cognitive dysfunction persists through affective and euthymic states in bipolar disorder (BD), its neurobiological correlates remain undetermined. We explore whole-cortex intracortical myelin (ICM) and cognition in BD-I and controls.

METHODS

T₁ -weighted images (3T) optimized for ICM measurement were analyzed using a surface-based approach. MRI signal was sampled at cortical mid-depth. Cognitive performance was measured via standardized computerized battery and paper-and-pencil Trails B.

RESULTS

ICM was associated with verbal memory (VM) in BD throughout a cortical network identified with pertinence to VM function, with strongest effects in left caudal middle temporal cortex and left dorsolateral prefrontal cortex (P_corrected  < 0.05). Subanalyses revealed specific association with correct word recognition, without delay. Processing speed, executive function, and reaction time were also predicted by ICM in BD, but not controls, although this did not survive Bonferroni correction.

CONCLUSION

This is the first study to show VM association with ICM in BD. ICM has been implicated in the integrity of neural connections and neural synchrony. VM dysfunction is one of the most replicated cognitive abnormalities in BD. Therefore, these results provide a novel mechanism for understanding cognitive dysfunction in BD, which can aid in the development of targeted therapeutics to improve cognitive outcomes in BD.

Effects of a 12-week running programme in youth and adults with complex mood disorders

Objective

Although numerous studies suggest a salutary effect of exercise on mood, few studies have explored the effect of exercise in patients with complex mental illness. Accordingly, we evaluated the impact of running on stress, anxiety and depression in youth and adults with complex mood disorders including comorbid diagnoses, cognitive and social impairment and high relapse rates.

Methods

Participants were members of a running group at St Joseph Healthcare Hamilton’s Mood Disorders Program, designed for clients with complex mood disorders. On a weekly basis, participants completed Cohen’s Perceived Stress Scale, Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI) questionnaires, providing an opportunity to evaluate the effect of running in this population.

Results

Data collected for 46 participants from April 2012 to July 2015 indicated a significant decrease in depression (p<0.0001), anxiety (p<0.0001) and stress (p=0.01) scores. Whereas younger participant age, younger age at onset of illness and higher perceived levels of friendship with other running group members (ps≤0.04) were associated with lower end-of-study depression, anxiety and stress scores, higher attendance was associated with decreasing BDI and BAI (ps≤0.01) scores over time.

Conclusions

Aerobic exercise in a supportive group setting may improve mood symptoms in youth and adults with complex mood disorders, and perceived social support may be an important factor in programme’s success. Further research is required to identify specifically the mechanisms underlying the therapeutic benefits associated with exercise-based therapy programmes.

Gray matter volumes in symptomatic and asymptomatic offspring of parents diagnosed with bipolar disorder

Children of parents diagnosed with bipolar disorder (BD), termed high-risk offspring (HRO), are at greater risk of developing psychiatric disorders compared to healthy children of healthy parents (HCO). Gray matter volume (GMV) abnormalities have been observed in HRO, however, these reports are inconsistent. We posit that this variability may be attributed to differences in methodology among offspring studies; in particular, the presence of psychiatric symptoms in HRO. Here, we directly compared GMVs between symptomatic and asymptomatic HRO, and HCO. High-resolution T1-weighted MR images were collected from 31 HRO (18 symptomatic and 13 asymptomatic) and 20 age- and sex-matched HCO. HRO had at least one parent diagnosed with BD. Symptomatic HRO were defined as having a psychiatric diagnosis other than BD, while asymptomatic HRO were required to be free of any psychiatric diagnosis. Scans were processed using voxel-based morphometry methods and between group analyses were performed in SPM. Compared to HCO, the HRO group showed decreased GMV in the right inferior orbitofrontal, right middle frontal, and bilateral superior and middle temporal regions. Both symptomatic and asymptomatic HRO groups showed decreased GMV in these regions separately when compared to HCO. When comparing symptomatic and asymptomatic HRO, GMVs were comparable in all regions except the lateral occipital cortex. Our study compared symptomatic and asymptomatic HRO directly. In doing so, we provided further support for the presence of discrete GMV deficits in HRO, and confirmed that these deficits are present irrespective of the presence of symptoms in HRO.

Cortical thickness in symptomatic and asymptomatic bipolar offspring

Children of parents diagnosed with bipolar disorder are at greater risk for developing a variety of psychiatric disorders, however, the reasons remain unknown. The present study aimed to investigate gray matter integrity in high-risk bipolar offspring (HRO) and healthy offspring (HCO) using cortical thickness techniques. Here we examined healthy control offspring (HCO; n=20) and HRO with (n=17) or without (n=13) psychiatric symptoms. T1-weighted images were collected from all offspring, and cortical thickness and age-cortical thickness correlations were compared. HRO showed cortical thinning in superior and inferior temporal regions, supramarginal, and caudal and rostral middle frontal regions compared to HCO. When comparing HRO with and without psychiatric symptoms, we found cortical thinning in symptomatic offspring in the superior frontal and somatosensory related cortices. Age-thickness correlations showed a relatively consistent negative relationship in most regions in HCO, while the reverse was true for the HRO. These regions included parahippocampal, lateral orbitofrontal, and inferior temporal regions. Our study provides evidence of cortical thickness reductions among symptomatic and asymptomatic high-risk offspring during youth. Some of these alterations, found in regions of emotion processing and regulation, are evident only when associated with the presence of psychiatric symptoms.

Accuracy of emotion labeling in children of parents diagnosed with bipolar disorder

BACKGROUND

Emotion labeling deficits have been posited as an endophenotype for bipolar disorder (BD) as they have been observed in both patients and their first-degree relatives. It remains unclear whether these deficits exist secondary to the development of psychiatric symptoms or whether they can be attributed to risk for psychopathology. To explore this, we investigated emotion processing in symptomatic and asymptomatic high-risk bipolar offspring (HRO) and healthy children of healthy parents (HCO).

METHODS

Symptomatic (n:18, age: 13.8 ± 2.6 years, 44% female) and asymptomatic (n:12, age: 12.8 ± 3.0 years, 42% female) HRO and age- and sex-matched HCO (n:20, age: 13.3 ± 2.5 years, 45% female) performed an emotion-labeling task. Total number of errors, emotion category and intensity of emotion error scores were compared. Correlations between total error scores and symptom severity were also investigated.

RESULTS

Compared to HCO, both HRO groups made more errors on the adult face task (pcor=0.014). The HRO group were 2.3 times [90%CI:0.9-6.3] more likely and 4.3 times [90%CI:1.3-14.3] more likely to make errors on sad and angry faces, respectively. With the exception of sad face type errors, we observed no significant differences in error patterns between symptomatic and asymptomatic HRO, and no correlations between symptom severity and total number of errors.

LIMITATIONS

This study was cross-sectional in design, limiting our ability to infer trajectories or heritability of these deficits.

CONCLUSIONS

This study provides further support for emotion labeling deficits as a candidate endophenotype for BD. Our study also suggests these deficits are not attributable to the presence of psychiatric symptoms.

Biological rhythms are independently associated with quality of life in bipolar disorder

Background

Evidence suggests that patients with bipolar disorder (BD) experience biological rhythm disturbances; however, no studies have examined the impact of this disruption on quality of life (QOL). The aim of this study is to investigate the influence of biological rhythm, depressive symptoms, sleep quality, and sleep medication use on QOL in BD.

Methods

Eighty BD subjects (44 depressed and 36 euthymic) completed questionnaires assessing QOL (WHOQOL-BREF), biological rhythm disruption (BRIAN), depressive symptoms (MADRS), and sleep quality (PSQI). The impact of biological rhythm disturbance, depressive symptoms severity, sleep quality, and sleep medication use on QOL was determined with multiple regression analyses.

Results

BRIAN (β = −0.31, t = −2.73, p < 0.01), MADRS (β = −0.30, t = −2.93, p < 0.01), and sleep medication use (β = −0.45, t = −2.55, p < 0.05) were significant predictors of QOL in this model (F_{4, 75} = 20.28; p < 0.0001). The relationship of these factors with subdomains of QOL showed that poorer social QOL was associated with greater biological rhythm disturbance (β = −0.43, t = −3.66, p < 0.01) and sleep medication use (β = −0.49, t = −2.35, p < 0.01), providing support for the social rhythm theory of BD. Physical QOL was associated with depression (β = −0.30, t = −2.93, p < 0.01) and biological rhythm disruption (β = −0.31, t = −2.73, p < 0.01). Main limitations include the cross-sectional assessment and the lack of objective measures of biological rhythms in relation to QOL.

Conclusions

Disruption in biological rhythm is associated with poor QOL in BD, independent of sleep disturbance, sleep medication use, and severity of depression. Treatment strategies targeting regulation of biological rhythms, such as sleep/wake cycles, eating patterns, activities, and social rhythms, are likely to improve QOL in this population.

The association between biological rhythms, depression, and functioning in bipolar disorder: a large multi-center study

OBJECTIVE

We examined the relationship between biological rhythms and severity of depressive symptoms in subjects with bipolar disorder and the effects of biological rhythms alterations on functional impairment.

METHOD

Bipolar patients (n = 260) and healthy controls (n = 191) were recruited from mood disorders programs in three sites (Spain, Brazil, and Canada). Parameters of biological rhythms were measured using the Biological Rhythms Assessment in Neuropsychiatry (BRIAN), an interviewer administered questionnaire that assesses disruptions in sleep, eating patterns, social rhythms, and general activity.

RESULTS

Multivariate analyses of covariance showed significant intergroup differences after controlling for potential confounders (Pillai's F = 49.367; df = 2, P < 0.001). Depressed patients had the greatest biological rhythms disturbance, followed by patients with subsyndromal symptoms, euthymic patients, and healthy controls. Biological rhythms and HAMD scores were independent predictors of poor functioning (F = 12.841, df = 6, P < 0.001, R²  = 0.443).

CONCLUSION

Our study shows a dose-dependent association between the severity of depressive symptoms and degree of biological rhythms disturbance. Biological rhythms disturbance was also an independent predictor of functional impairment. Although the directionality of this relationship remains unknown, our results suggest that stability of biological rhythms should be an important target of acute and long-term management of bipolar disorder and may aid in the improvement of functioning.

Cortical thickness in bipolar disorder: a systematic review

OBJECTIVES

Bipolar disorder (BD) is a debilitating illness, the psychopathology of which is associated with aberrant structural and functional differences in the brain. Despite the many advances in psychiatric research, our understanding of the complex neurobiological underpinnings of BD remains incomplete. The aim of this review was to critically examine all available published magnetic resonance imaging (MRI) research reporting cortical thickness in BD with respect to a healthy population and/or other psychiatric samples.

METHODS

The systematic search encompassed all relevant studies published until November 2014. Relevant papers were identified through an online search of select databases (MEDLINE and EMBASE) using key terms bipolar disorder or mania, and cortical thickness. Two independent raters determined the eligibility of papers and performed separate data extraction to ensure quality and accuracy of reporting.

RESULTS

A total of 17 papers met the criteria and were included in this review. Compared to a healthy population, the majority of studies reported decreased cortical thickness in the left anterior cingulate/paracingulate and the left superior temporal gyrus, as well as several prefrontal regions bilaterally in patients with BD. Studies also show consistency of cortical thinning in individuals with BD and schizophrenia in frontal and temporal regions, suggesting some common neuropathology.

CONCLUSIONS

This systematic review further supports a link between specific structural brain abnormalities and BD. Future studies should investigate cortical thickness with respect to at-risk populations to determine whether these neuropathologies develop before or after the onset of BD.

Orbitofrontal cortex gray matter volumes in bipolar disorder patients: a region-of-interest MRI study

OBJECTIVES

Functional and postmortem studies suggest that the orbitofrontal cortex (OFC) is involved in the pathophysiology of bipolar disorder (BD). This anatomical magnetic resonance imaging (MRI) study examined whether BD patients have smaller OFC gray matter volumes compared to healthy comparison subjects (HC).

METHODS

Twenty-eight BD patients were compared to 28 age- and gender-matched HC. Subjects underwent a 1.5T MRI with 3D spoiled gradient recalled acquisition. Total OFC and medial and lateral subdivisions were manually traced by a blinded examiner. Images were segmented and gray matter volumes were calculated using an automated method.

RESULTS

Analysis of covariance, with intracranial volume as covariate, showed that BD patients and HC did not differ in gray matter volumes of total OFC or its subdivisions. However, total OFC gray matter volume was significantly smaller in depressed patients (n = 10) compared to euthymic patients (n = 18). Moreover, total OFC gray matter volumes were inversely correlated with depressive symptom intensity, as assessed by the Hamilton Depression Rating Scale. OFC gray matter volumes were not related to lithium treatment, age at disease onset, number of episodes, or family history of mood disorders.

CONCLUSIONS

Our results suggest that abnormal OFC gray matter volumes are not a pervasive characteristic of BD, but may be associated with specific clinical features of the disorder.

Three-dimensional mapping of hippocampal anatomy in unmedicated and lithium-treated patients with bipolar disorder

Declarative memory impairments are common in patients with bipolar illness, suggesting underlying hippocampal pathology. However, hippocampal volume deficits are rarely observed in bipolar disorder. Here we used surface-based anatomic mapping to examine hippocampal anatomy in bipolar patients treated with lithium relative to matched control subjects and unmedicated patients with bipolar disorder. High-resolution brain magnetic resonance images were acquired from 33 patients with bipolar disorder (21 treated with lithium and 12 unmedicated), and 62 demographically matched healthy control subjects. Three-dimensional parametric mesh models were created from manual tracings of the hippocampal formation. Total hippocampal volume was significantly larger in lithium-treated bipolar patients compared with healthy controls (by 10.3%; p=0.001) and unmedicated bipolar patients (by 13.9%; p=0.003). Statistical mapping results, confirmed by permutation testing, revealed localized deficits in the right hippocampus, in regions corresponding primarily to cornu ammonis 1 subfields, in unmedicated bipolar patients, as compared to both normal controls (p=0.01), and in lithium-treated bipolar patients (p=0.03). These findings demonstrate the sensitivity of these anatomic mapping methods for detecting subtle alterations in hippocampal structure in bipolar disorder. The observed reduction in subregions of the hippocampus in unmedicated bipolar patients suggests a possible neural correlate for memory deficits frequently reported in this illness. Moreover, increased hippocampal volume in lithium-treated bipolar patients may reflect postulated neurotrophic effects of this agent, a possibility warranting further study in longitudinal investigations.

MRI study of the cerebellum in young bipolar patients

Prior studies demonstrate structural abnormalities of cerebellar vermis in adult bipolar patients. Cerebella of 16 young bipolar patients (mean age+/-S.D.=15.5+/-3.4) and 21 healthy controls (mean age+/-S.D.=16.9+/-3.8) were examined using magnetic resonance imaging. The volumes of right, left and total cerebellum, vermis, and areas of vermal regions V1 (lobules I-V), V2 (lobules VI-VII), and V3 (lobules VIII-X) were measured. Analysis of covariance, with age, gender, and intra-cranial brain volume as covariates, revealed no significant differences in cerebellum or vermis measures between patients and controls; however, there was a trend to smaller vermis V2 areas in patients (p=0.06). The number of previous affective episodes and vermis area V2 were inversely correlated (partial correlation coefficient=-0.97, P=0.001) in the male bipolar patient group. Our results are preliminary, but consistent with the findings from studies in adult bipolar patients suggesting the involvement of structural changes in cerebellar vermis in the pathophysiology of bipolar disorder.

Prefrontal gray matter increases in healthy individuals after lithium treatment: a voxel-based morphometry study

The objective of this study was to test the hypothesis that 4 weeks of lithium administration would be associated with changes in brain gray and white matter volumes in healthy individuals. Thirteen right-handed healthy volunteers (6 females, mean age=25.9+/-10.0 years) were studied. 3D SPGR MRIs (TR=25 ms, TE=5 ms, slice-thickness=1.5 mm) were acquired using a 1.5 T GE Signa Imaging System, at baseline and after 4 weeks of lithium administration at therapeutically relevant doses. Optimized voxel-based morphometry (VBM) analyses were conducted. Left and right dorsolateral prefrontal cortex and left anterior cingulate gray matter volumes increased significantly following lithium administration. Total white matter volume was increased, whereas total brain volume and total gray matter volume were not significantly changed following 4 weeks of lithium. Lithium treatment resulted in prefrontal regional gray matter volume increases in healthy volunteers, as well as increases in total white matter volume. Whether these changes are mediated by neurotrophic/neuroprotective or osmotic effects remains unknown.

Greater cortical gray matter density in lithium-treated patients with bipolar disorder

BACKGROUND

The neurobiological underpinnings of bipolar disorder are not well understood. Previous neuroimaging findings have been inconsistent; however, new methods for three-dimensional (3-D) computational image analysis may better characterize neuroanatomic changes than standard volumetric measures.

METHODS

We used high-resolution magnetic resonance imaging and cortical pattern matching methods to map gray matter differences in 28 adults with bipolar disorder, 70% of whom were lithium-treated (mean age = 36.1 +/- 10.5; 13 female subject), and 28 healthy control subjects (mean age = 35.9 +/- 8.5; 11 female subjects). Detailed spatial analyses of gray matter density (GMD) were conducted by measuring local proportions of gray matter at thousands of homologous cortical locations.

RESULTS

Gray matter density was significantly greater in bipolar patients relative to control subjects in diffuse cortical regions. Greatest differences were found in bilateral cingulate and paralimbic cortices, brain regions critical for attentional, motivational, and emotional modulation. Secondary region of interest (ROI) analyses indicated significantly greater GMD in the right anterior cingulate among lithium-treated bipolar patients (n = 20) relative to those not taking lithium (n = 8).

CONCLUSIONS

These brain maps are consistent with previous voxel-based morphometry reports of greater GMD in portions of the anterior limbic network in bipolar patients and suggest neurotrophic effects of lithium as a possible etiology of these neuroanatomic differences.

Context processing performance in bipolar disorder patients

OBJECTIVES

Context processing is the adaptive control of current behavior through the use of prior context information. It has been found to be impaired in schizophrenia. Some studies have indicated that, compared with patients with schizophrenia, those with bipolar disorder (BPD) display a similar but less severe neuropsychological pattern of impairment. However, this cognitive dimension has not yet been examined in BPD patients in the existing literature.

METHODS

An expectancy version of the AX continuous performance test (AX-CPT) was administered to 15 bipolar outpatients and 26 healthy controls. Patients with schizophrenia, in which context processing deficits are known to occur, were used as a reference group.

RESULTS

Bipolar patients showed a context processing deficit relative to healthy controls, although this was less severe and generalized than in schizophrenia patients.

CONCLUSIONS

These findings suggest there are milder impairments in context processing in BPD compared with schizophrenia. However, the severity of possible context processing deficits in BPD may have been underestimated in our sample of mostly euthymic outpatients.

Fronto-limbic brain structures in suicidal and non-suicidal female patients with major depressive disorder

Our knowledge about the neurobiology of suicide is limited. It has been proposed that suicidal behavior generally requires biological abnormalities concomitant with the personality trait of impulsivity/aggression, besides an acute psychiatric illness or psychosocial stressor. We investigated fronto-limbic anatomical brain abnormalities in suicidal and non-suicidal adult female patients with unipolar depression. Our sample consisted of seven suicidal unipolar patients, 10 non-suicidal unipolar patients and 17 healthy female comparison subjects. The criterion for suicidality was one or more documented lifetime suicide attempts. A 1.5T GE Signa Imaging System running version Signa 5.4.3 software was used to acquire the magnetic resonance imaging images. All anatomical structures were measured blindly, with the subjects' identities and group assignments masked. We used analysis of covariance with age and intracranial volume as covariates and the Tukey-Kramer procedure to compare suicidal patients, non-suicidal patients and healthy comparison subjects. Suicidal patients had smaller right and left orbitofrontal cortex gray matter volumes compared with healthy comparison subjects. Suicidal patients had larger right amygdala volumes than non-suicidal patients. Abnormalities in the orbitofrontal cortex and amygdala in suicidal patients may impair decision-making and predispose these patients to act more impulsively and to attempt suicide.

Anatomical measurements of the orbitofrontal cortex in child and adolescent patients with bipolar disorder

Imaging studies indicate smaller orbitofrontal cortex (OFC) volume in mood disorder patients compared with healthy subjects. We sought to determine whether child and adolescent patients with bipolar disorder have smaller OFC volumes than healthy controls. Fourteen children and adolescents meeting DSM-IV criteria for bipolar disorder (six males and eight females with a mean age+/-S.D.=15.5+/-3.2 years) and 20 healthy controls (11 males and nine females with mean age+/-S.D.=16.9+/-3.8 years) were studied. Orbitofrontal cortex volume was measured using magnetic resonance imaging. Male bipolar patients had smaller gray matter volumes in medial (p=0.044), right medial (0.037) and right (p=0.032) lateral OFC subdivisions compared to male controls. In contrast, female patients had larger gray matter volumes in left (p=0.03), lateral (p=0.012), left lateral (p=0.007), and trends for larger volumes in right lateral and left medial OFC subdivisions compared with female controls. Male patients exhibit smaller gray matter volumes, while female patients exhibit larger volumes in some OFC sub-regions. Gender differences in OFC abnormalities may be involved in illness pathophysiology among young bipolar patients.

MRI study of thalamus volumes in juvenile patients with bipolar disorder

In vivo imaging studies suggest functional abnormalities of the thalamus in adult patients with bipolar disorder, but the presence of anatomical abnormalities is controversial. Our objective in this study was to compare the thalamus volumes of children and adolescents with bipolar disorder versus healthy controls to determine whether any morphological abnormalities exist early in illness course. We studied 16 patients with bipolar disorder according to DSM-IV criteria (mean age+/-SD=15.5+/-3.4 years) and 21 healthy control subjects (mean age+/-SD=16.9+/-3.8 years). Blinded examiners measured thalamic gray matter volumes with a semiautomated technique. Analysis of covariance, with age, gender, and intracranial brain volume as covariates, revealed no significant differences in left and right thalamic volumes between patients with bipolar disorder and healthy controls. Our findings indicate there are no significant differences in thalamus size between children and adolescents with bipolar disorder and healthy comparison subjects, in contrast to available findings for schizophrenia and first-break psychosis. Any differences in thalamus size that may exist between patients with bipolar disorder and healthy controls must amount to small effect sizes.

Smaller cingulate volumes in unipolar depressed patients

BACKGROUND

The anterior cingulate cortex is a key structure in brain networks involved in mood regulation. Abnormalities in this brain region are possibly implicated in the pathophysiology of depression. This anatomical magnetic resonance imaging (MRI) study compared cingulate cortex volumes in unipolar depressed patients and age- and gender-matched healthy control subjects.

METHODS

Thirty-one unmedicated DSM-IV unipolar patients (24 female, aged 39.2 +/- 11.9 years [mean +/- SD]) and 31 healthy control subjects (24 female, aged 36.7 +/- 10.7 years) were studied in a 1.5-T GE Signa magnet (General Electric Medical Systems, Milwaukee, Wisconsin). Cingulate volumes were compared by analysis of covariance with intracranial volume as the covariate.

RESULTS

The unipolar patients had significantly smaller anterior and posterior cingulate volumes bilaterally compared with healthy control subjects. When patients were divided into currently depressed (n = 21) and remitted (n = 10) subgroups, currently depressed patients had significantly smaller anterior and posterior cingulate volumes bilaterally compared with healthy control subjects, whereas remitted patients had significantly smaller left anterior cingulate volumes compared with healthy individuals.

CONCLUSIONS

Gray matter abnormalities in the cingulate cortex are implicated in the pathophysiology of unipolar depression. Smaller cingulate volumes in currently depressed patients support the hypothesis that cingulate cortex abnormalities are state dependent, whereas changes in left anterior cingulate might be trait related.

MRI study of corpus callosum in children and adolescents with bipolar disorder

This structural magnetic resonance imaging study examined the length, areas, and circularity of the corpus callosum (CC) in 16 children and adolescents with bipolar disorder and 21 healthy controls. Bipolar disorder patients had lower circularity of the CC splenium compared with healthy controls. No significant differences in CC length or area were observed, suggesting that reported CC abnormalities appear late in the course of bipolar disorder.

Reduced NAA levels in the dorsolateral prefrontal cortex of young bipolar patients

OBJECTIVE

Converging evidence implicates prefrontal circuits in the pathophysiology of bipolar disorder. Proton spectroscopy studies performed in adult bipolar patients assessing prefrontal regions have suggested decreased levels of N-acetylaspartate (NAA), a putative marker of neuronal integrity. In order to examine whether such abnormalities would also be found in younger patients, a 1H spectroscopy study was conducted that focused on the dorsolateral prefrontal cortex of children and adolescents with bipolar disorder.

METHOD

The authors examined the levels of NAA, creatine plus phosphocreatine, and choline-containing molecules in the left dorsolateral prefrontal cortex of 14 bipolar disorder patients (mean age=15.5 years, SD=3, eight female) and 18 healthy comparison subjects (mean age=17.3, SD=3.7, seven female) using short echo time, single-voxel in vivo 1H spectroscopy. Absolute metabolite levels were determined using the water signal as an internal reference.

RESULTS

Bipolar patients presented significantly lower NAA levels and a significant inverse correlation between choline-containing molecules and number of previous affective episodes. No differences were found for other metabolites.

CONCLUSIONS

These findings suggest that young bipolar patients have decreased NAA levels in the dorsolateral prefrontal cortex, similar to what was previously reported in adult patients. Such changes may reflect an underdevelopment of dendritic arborizations and synaptic connections. These neuronal abnormalities in the dorsolateral prefrontal cortex of bipolar disorder youth are unlikely to represent long-term degenerative processes, at least in the subgroup of patients where the illness had relatively early onset.

Cingulate cortex anatomical abnormalities in children and adolescents with bipolar disorder

OBJECTIVE

In vivo imaging studies have suggested anatomical and functional abnormalities in the anterior cingulate in adults with mood disorders. This anatomical magnetic resonance imaging study examined the cingulate cortex in children and adolescents with bipolar disorder and matched healthy comparison subjects.

METHOD

Sixteen patients (mean age=15.5 years, SD=3.4) with DSM-IV bipolar disorder and 21 matched healthy comparison subjects (mean age=16.9 years, SD=3.8) were studied. Three-dimensional gradient echo imaging was performed (TR=25 msec, TE=5 msec, slice thickness=1.5 mm) in a 1.5-T GE Signa magnet. Cingulate volumes were compared by using analysis of covariance, with age and intracranial volume as covariates.

RESULTS

The patients with bipolar disorder had significantly smaller mean volumes relative to the healthy subjects in the left anterior cingulate (mean=2.49 cm(3 [SD=0.28] versus 3.60 cm3 [SD=0.12], respectively), left posterior cingulate (2.53 cm3 [SD=0.32] versus 2.89 cm3 [SD=0.09]), and right posterior cingulate (2.19 cm3 [SD=0.13] versus 2.28 cm3 [SD=0.08]). No significant between-group difference was found for the right anterior cingulate (2.64 cm3 [SD=0.21] versus 2.71 cm3 [SD=0.10]).

CONCLUSIONS

The findings indicate smaller cingulate volumes in children and adolescents with bipolar disorder, suggesting that such abnormalities may be present early in the illness course.

Anatomical MRI study of corpus callosum in unipolar depression

Previous studies have suggested abnormal cerebral lateralization in major depressive disorder (MDD). Few controlled MRI studies have investigated the corpus callosum (CC), the largest commissura connecting the two cerebral hemispheres, in MDD. This study investigated anatomical abnormalities in the CC and its subdivisions in MDD patients. Twenty-two unmedicated MDD patients and 39 healthy subjects underwent brain magnetic resonance imaging (MRI). Measurements of the CC and its sub-regions were performed with a semi-automated software (NIH Image, version 1.62). ANCOVA with age, gender, and intra-cranial volume (ICV) as covariates showed no significant differences in CC measurements between patients and controls (df=1,56; p>0.05). However, patients with familial MDD had a significantly larger middle genu area (F(1,45)=4.252; p=0.045) compared to healthy controls, and significantly larger middle genu (F(1,13)=5.366; p=0.037), anterior splenium (F(1,13)=6.27; p=0.026), and middle splenium areas (F(1,13)=4.706; p=0.049) compared to patients with non-familial MDD. Although preliminary, our findings suggest that anatomical abnormalities in CC may be restricted to patients with familial MDD, with possible enlargement of CC in this particular sub-group. The possible role of callosal abnormalities in the pathogenesis of mood disorders should be further examined.

Normal pituitary volumes in children and adolescents with bipolar disorder: a magnetic resonance imaging study

The volume of the pituitary gland in adults with bipolar disorder has previously been reported to be smaller than that of healthy controls. Such abnormalities would be consistent with the HPA dysfunction reported in this illness. We conducted a study of children and adolescents with bipolar disorder to determine whether size abnormalities in the pituitary gland are already present early in illness course. Magnetic resonance imaging (MRI) morphometric analysis of the pituitary gland was carried out in 16 DSM-IV children and adolescents with bipolar disorder (mean age+/-sd=15.5+/-3.4 years) and 21 healthy controls (mean age+/-sd=16.9+/-3.8 years). Subjects underwent a 1.5 T MRI, with 3-D Spoiled Gradient Recalled (SPGR) acquisition. There was no statistically significant difference between pituitary gland volumes of bipolar patients compared to healthy controls (ANCOVA, age, gender, and ICV as covariates; F=1.77, df=1,32, P=.19). There was a statistically significant direct relationship between age and pituitary gland volume in both groups (r=.59, df=17, P=.007 for healthy controls; r=.61, df=12, P=.008 for bipolar patients). No evidence of size abnormalities in the pituitary gland was found in child and adolescent bipolar patients, contrary to reports involving adult bipolar patients. This suggests that anatomical abnormalities in this structure may develop later in illness course as a result of continued HPA dysfunction.

1H magnetic resonance spectroscopy investigation of the dorsolateral prefrontal cortex in bipolar disorder patients

BACKGROUND

Magnetic resonance spectroscopy studies (MRS) reported abnormally low levels of N-acetylaspartate (NAA, a marker of neuronal integrity) in dorsolateral prefrontal cortex (DLPFC) of adult bipolar patients, suggesting possible neuronal dysfunction. Furthermore, recent MRS reports suggested possible lithium-induced increase in NAA levels in bipolar patients. We examined with in vivo (1)H MRS NAA levels in the DLPFC of adult bipolar patients.

METHODS

Ten DSM-IV bipolar disorder patients (6 lithium-treated, 4 drug-free) and 32 healthy controls underwent a short echo-time 1H MRS session, which localized an 8 cm3 single-voxel in the left DLPFC using a STEAM sequence.

RESULTS

No significant differences between the two groups were found for NAA, choline-containing molecules (GPC+PC), or phosphocreatine plus creatine (PCr+Cr) (Student t-test, p > 0.05). Nonetheless, NAA/PCr+Cr ratios were significantly increased in lithium-treated bipolar subjects compared to unmedicated patients and healthy controls (Mann-Whitney U-test, p < 0.05).

LIMITATIONS

Relatively small sample size may have reduced the statistical power of our analyses and the utilization of a single-voxel approach did not allow for the examination of other cortical brain areas.

CONCLUSIONS

This study did not find abnormally reduced levels of NAA in left DLPFC of adult bipolar patients, in a sample of patients who were mostly on medications. However, elevated NAA/PCr+Cr ratios were shown in lithium-treated bipolar patients. Longitudinal 1H MRS studies should further examine NAA levels in prefrontal cortex regions in untreated bipolar patients before and after mood stabilizing treatment.

Structural brain changes in bipolar disorder using deformation field morphometry

The objective of this study was to investigate anatomical brain abnormalities in adult bipolar patients using a deformation field morphometry technique. Our sample consisted of 32 right-handed bipolar I patients (men/women=16/16) and 32 right-handed, age and gender matched healthy controls. Deformation field morphometry analysis was performed on three-dimensional spoiled gradient recalled acquisition images. We found gender-specific structural differences between bipolar patients and healthy individuals. Bipolar men had significantly larger lateral ventricles (especially pronounced in the left hemisphere) and smaller left dorsolateral prefrontal cortex than healthy male controls. Our results are complementary to the findings of functional imaging and post-mortem studies that demonstrate abnormalities in the dorsolateral prefrontal cortex in bipolar patients.

Developmental abnormalities in striatum in young bipolar patients: a preliminary study

OBJECTIVES

Anatomical abnormalities in the basal ganglia of adult mood disorder patients have been reported. To investigate whether these abnormalities are present early in illness course, we compared the volume of striatal structures in young bipolar patients and healthy controls.

METHODS

Brain magnetic resonance images of 15 children and adolescents who met DSM-IV criteria for bipolar disorders and 21 healthy controls were obtained. Measurements were performed manually, by trained evaluators, who were blind to subjects' diagnosis. The volumes of caudate and putamen were compared in patients and controls.

RESULTS

The volumes of striatal structures were not significantly different in patients and controls (ANCOVA, p > 0.05). However, we found a significant inverse relationship between age and the volumes of left caudate (r = -0.72, p < 0.01), right caudate (r = -0.66, p = 0.02) and left putamen (r = -0.71, p = 0.01) in bipolar patients, not present in healthy controls.

CONCLUSIONS

Abnormalities in striatal development may be involved in the pathophysiology of bipolar disorder.

Developmental abnormalities in striatum in young bipolar patients: a preliminary study

OBJECTIVES

Anatomical abnormalities in the basal ganglia of adult mood disorder patients have been reported. To investigate whether these abnormalities are present early in illness course, we compared the volume of striatal structures in young bipolar patients and healthy controls.

METHODS

Brain magnetic resonance images of 15 children and adolescents who met DSM-IV criteria for bipolar disorders and 21 healthy controls were obtained. Measurements were performed manually, by trained evaluators, who were blind to subjects' diagnosis. The volumes of caudate and putamen were compared in patients and controls.

RESULTS

The volumes of striatal structures were not significantly different in patients and controls (ANCOVA, p > 0.05). However, we found a significant inverse relationship between age and the volumes of left caudate (r = -0.72, p < 0.01), right caudate (r = -0.66, p = 0.02) and left putamen (r = -0.71, p = 0.01) in bipolar patients, not present in healthy controls.

CONCLUSIONS

Abnormalities in striatal development may be involved in the pathophysiology of bipolar disorder.

1H Magnetic resonance spectroscopy study of dorsolateral prefrontal cortex in unipolar mood disorder patients

Neuroimaging and postmortem studies have suggested the involvement of the dorsolateral prefrontal cortex (DLPFC) in the pathophysioloy of unipolar disorder. We examined with in vivo 1H magnetic resonance spectroscopy (MRS) the levels of specific metabolites in the DLPFC of adult unipolar patients and the role of illness chronicity on DLPFC abnormalities. Nineteen unmedicated unipolar mood disorder patients and 19 age- and gender-matched healthy controls underwent a short echo-time 1H MRS examination localized to an 8-cm3 single voxel placed in the left DLPFC. There were no significant differences in metabolite levels, including N-acetylaspartate (NAA), phosphocreatine plus creatine (PCr+Cr) and choline-containing-compounds (GPC+PC), between the two groups. However, NAA/PCr+Cr ratios were significantly lower in the chronic than in the less chronically ill patients and healthy controls. The low levels of NAA/PCr+Cr ratios in the left DLPFC of unipolar patients who had been more chronically ill suggest a potential role for illness chronicity in neuronal abnormalities in the DLPFC in unipolar disorder. This could possibly be accounted for by neurodegenerative processes arising with the progression of the illness. Future 1H MRS investigations should longitudinally examine the role of illness chronicity on DLPFC abnormalities and their relationship with the symptoms of unipolar disorder.

Obsessive-compulsive symptoms in adults with history of rheumatic fever, Sydenham's chorea and type I diabetes mellitus: preliminary results

OBJECTIVE

Rheumatic fever (RF) associated with Sydenham's chorea (a neurological variant of RF), but not RF without chorea, has been acutely related to obsessive-compulsive symptomatology/disorder (OCS/OCD). This study investigated the presence of OCS in adults who had RF with or without chorea in childhood.

METHOD

The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) was used to evaluate OCS in 38 adults with history of RF (13 with chorea; 25 without chorea) or diabetes (controls; n = 19).

RESULTS

The OCS was similar in both groups, although the intensity of symptoms was not clinically relevant. Moreover, subjects with RF with or without chorea did not score differently in the Y-BOCS.

CONCLUSION

The similar occurrence of OCS in patients with history of RF and diabetes suggests that the development of this symptomatology, triggered by group A beta-haemolytic streptococcus infections, is restricted to the RF acute phase, occurred during infancy, and did not seem to predispose the appearance of OCS in adulthood.

Subgenual prefrontal cortex of child and adolescent bipolar patients: a morphometric magnetic resonance imaging study

The subgenual prefrontal cortex (SGPFC) plays an important role in emotional processing. We carried out a magnetic resonance imaging (MRI) study comparing the volume of the SGPFC in child and adolescent bipolar patients and healthy controls. The sample consisted of 15 children and adolescents who met DSM-IV criteria for bipolar disorder (mean age +/- S.D.=15.5 +/- 3.5 years) and 21 healthy adolescents (mean age +/- S.D.=16.9 +/- 3.8 years). MR images were obtained with a 1.5 T GE Signa Imaging System with Signa 5.4.3 software. SGPFC volumes were measured with the semi-automated software MedX (Sensor Systems, Sterling, VA, USA). ANCOVA was performed to compare SGPFC volumes between groups, using age, gender and intra-cranial volume (ICV) as covariates. The volumes (mean +/- S.D.) of the right and left SGPFC for bipolar patients were 291.27 +/- 88.70 mm(3) and 284.86 +/- 83.98 mm(3), respectively. For healthy controls, the right and left SGPFC volumes were 284.95 +/- 73.33 mm(3) and 307.55 +/- 73.67 mm(3), respectively. There were no statistically significant differences between groups regarding right or left SGPFC volumes. We found no evidence of volumetric abnormalities in the SGPFC of bipolar children and adolescents.