Quality of clinical management of cardiometabolic risk factors in patients with severe mental illness in a specialist mental health care setting

PURPOSE

Cardiometabolic disease in patients with severe mental illness is a major cause of shortened life expectancy. There is sparse evidence of real-world clinical risk prevention practice. We investigated levels of assessments of cardiometabolic risk factors and risk management interventions in patients with severe mental illness in the Norwegian mental health service according to an acknowledged international standard.

METHODS

We collected data from 264 patients residing in six country-wide health trusts for: (a) assessments of cardiometabolic risk and (b) assessments of levels of risk reducing interventions. Logistic regressions were employed to investigate associations between risk and interventions.

RESULTS

Complete assessments of all cardiometabolic risk variables were performed in 50% of the participants and 88% thereof had risk levels requiring intervention according to the standard. Smoking cessation advice was provided to 45% of daily smokers and 4% were referred to an intervention program. Obesity was identified in 62% and was associated with lifestyle interventions. Reassessment of psychotropic medication was done in 28% of the obese patients. Women with obesity were less likely to receive dietary advice, and use of clozapine or olanzapine reduced the chances for patients with obesity of getting weight reducing interventions.

CONCLUSIONS

Nearly nine out of the ten participants were identified as being at cardiometabolic high risk and only half of the participants were adequately screened. Women with obesity and patients using antipsychotics with higher levels of cardiometabolic side effects had fewer adequate interventions. The findings underscore the need for standardized recommendations for identification and provision of cardiometabolic risk reducing interventions in all patients with severe mental illness.

Psychodynamic case formulations without technical language: a reliability study

Background

To bridge the gap between symptoms and treatment, constructing case formulations is essential for clinicians. Limited scientific value has been attributed to case formulations because of problems with quality, reliability, and validity. For understanding, communication, and treatment planning beyond each specific clinician-patient dyad, a case formulation must convey valid information concerning the patient, as well as being a reliable source of information regardless of the clinician’s theoretical orientation. The first aim of the present study is to explore the completeness of unstructured psychodynamic formulations, according to four components outlined in the Case Formulation Content Coding Method (CFCCM). The second aim is to estimate the reliability of independent formulations and their components, using similarity ratings of matched versus mismatched cases.

Methods

This study explores psychodynamic case formulations as made by two or more experienced clinicians after listening to an evaluation interview. The clinicians structured the formulations freely, with the sole constraint that technical, theory-laden terminology should be avoided. The formulations were decomposed into components after all formulations had been written.

Results

The results indicated that most formulations were adequately comprehensive, and that overall reliability of the formulations was high (> 0.70) for both experienced and inexperienced clinician raters, although the lower bound reliability estimate of the formulation component deemed most difficult to rate - inferred mechanisms - was marginal, 0.61.

Conclusions

These results were achieved on case formulations made by experienced clinicians using simple experience-near language and minimizing technical concepts, which indicate a communicative quality in the formulations that make them clinically sound.

Trial registration

linicalTrials.gov Identifier: NCT00423462. 10.1007/s00432-018-2781-7., January 18, 2007.

Cortical thickness abnormalities in bipolar disorder patients with a lifetime history of auditory hallucinations

OBJECTIVES

We aimed to investigate morphometric correlates of auditory hallucinations in bipolar disorder (BD) by comparing cortical thickness and cortical surface area in bipolar disorder patients with (BD+) and without (BD-) a lifetime history of auditory hallucinations. Based on previous findings in schizophrenia patients, we hypothesized that the cortex would be thinner in the auditory cortex in BD+ compared to BD-.

METHODS

Bipolar disorder spectrum (n = 157) patients and healthy controls (n = 279) underwent 1.5T magnetic resonance imaging (MRI) scanning. Hypothesis-driven analyses of cortical thickness and surface area in regions of the auditory cortex (Heschl's gyrus [HG], planum temporale and superior temporal gyrus) were conducted comparing BD+ (n = 49) and BD- (n = 108) using linear regression models, covaried for age and sex. Furthermore, we explored vertex-wise group differences in thickness and surface area across the whole cerebral cortex.

RESULTS

Hypothesis-driven analyses:BD+ had significantly thicker cortex in the left HG compared to BD- (B = 0.128, P = .0046). The finding was not explained by duration of illness, global functioning, bipolar subtype, IQ or use of antipsychotic, antidepressant or antiepileptic medication, or by lithium. Exploratory analyses: A small region of thicker cortex in BD+ compared to BD- was seen in the left superior parietal lobule (false discovery rate <0.05). There were no significant group differences in cortical surface area.

CONCLUSION

A lifetime history of auditory hallucinations in BD was associated with cortical thickness alterations in both the left HG and the superior parietal lobule. Contrary to our hypothesis, BD+ showed thicker, rather than thinner cortex compared to BD-. Replications in independent samples are needed.

Cortical Brain Abnormalities in 4474 Individuals With Schizophrenia and 5098 Control Subjects via the Enhancing Neuro Imaging Genetics Through Meta Analysis (ENIGMA) Consortium

BACKGROUND

The profile of cortical neuroanatomical abnormalities in schizophrenia is not fully understood, despite hundreds of published structural brain imaging studies. This study presents the first meta-analysis of cortical thickness and surface area abnormalities in schizophrenia conducted by the ENIGMA (Enhancing Neuro Imaging Genetics through Meta Analysis) Schizophrenia Working Group.

METHODS

The study included data from 4474 individuals with schizophrenia (mean age, 32.3 years; range, 11-78 years; 66% male) and 5098 healthy volunteers (mean age, 32.8 years; range, 10-87 years; 53% male) assessed with standardized methods at 39 centers worldwide.

RESULTS

Compared with healthy volunteers, individuals with schizophrenia have widespread thinner cortex (left/right hemisphere: Cohen's d = -0.530/-0.516) and smaller surface area (left/right hemisphere: Cohen's d = -0.251/-0.254), with the largest effect sizes for both in frontal and temporal lobe regions. Regional group differences in cortical thickness remained significant when statistically controlling for global cortical thickness, suggesting regional specificity. In contrast, effects for cortical surface area appear global. Case-control, negative, cortical thickness effect sizes were two to three times larger in individuals receiving antipsychotic medication relative to unmedicated individuals. Negative correlations between age and bilateral temporal pole thickness were stronger in individuals with schizophrenia than in healthy volunteers. Regional cortical thickness showed significant negative correlations with normalized medication dose, symptom severity, and duration of illness and positive correlations with age at onset.

CONCLUSIONS

The findings indicate that the ENIGMA meta-analysis approach can achieve robust findings in clinical neuroscience studies; also, medication effects should be taken into account in future genetic association studies of cortical thickness in schizophrenia.

Cortical abnormalities in bipolar disorder: an MRI analysis of 6503 individuals from the ENIGMA Bipolar Disorder Working Group

Despite decades of research, the pathophysiology of bipolar disorder (BD) is still not well understood. Structural brain differences have been associated with BD, but results from neuroimaging studies have been inconsistent. To address this, we performed the largest study to date of cortical gray matter thickness and surface area measures from brain magnetic resonance imaging scans of 6503 individuals including 1837 unrelated adults with BD and 2582 unrelated healthy controls for group differences while also examining the effects of commonly prescribed medications, age of illness onset, history of psychosis, mood state, age and sex differences on cortical regions. In BD, cortical gray matter was thinner in frontal, temporal and parietal regions of both brain hemispheres. BD had the strongest effects on left pars opercularis (Cohen's d=-0.293; P=1.71 × 10^-21), left fusiform gyrus (d=-0.288; P=8.25 × 10^-21) and left rostral middle frontal cortex (d=-0.276; P=2.99 × 10^-19). Longer duration of illness (after accounting for age at the time of scanning) was associated with reduced cortical thickness in frontal, medial parietal and occipital regions. We found that several commonly prescribed medications, including lithium, antiepileptic and antipsychotic treatment showed significant associations with cortical thickness and surface area, even after accounting for patients who received multiple medications. We found evidence of reduced cortical surface area associated with a history of psychosis but no associations with mood state at the time of scanning. Our analysis revealed previously undetected associations and provides an extensive analysis of potential confounding variables in neuroimaging studies of BD.

Alcohol use is associated with thinner cerebral cortex and larger ventricles in schizophrenia, bipolar disorder and healthy controls

BACKGROUND

Excessive alcohol use is associated with brain damage but less is known about brain effects from moderate alcohol use. Previous findings indicate that patients with severe mental illness, particularly schizophrenia, are vulnerable to alcohol-related brain damage. We investigated the association between levels of alcohol consumption and cortical and subcortical brain structures in schizophrenia and bipolar disorder patients and healthy controls, and investigated for group differences for this association.

METHOD

1.5 T structural magnetic resonance images were acquired of 609 alcohol-using participants (165 schizophrenia patients, 172 bipolar disorder patients, 272 healthy controls), mean (s.d.) age 34.2 (9.9) years, 52% men. Past year alcohol use was assessed with the Alcohol Use Disorder Identification Test - Consumption part (AUDIT-C). General linear models were used to investigate associations between AUDIT-C score and cortical thickness, surface area, and total brain and subcortical volumes.

RESULTS

Increasing AUDIT-C score was linearly associated with thinner cortex in medial and dorsolateral frontal and parieto-occipital regions, and with larger left lateral ventricle volume. There was no significant interaction between AUDIT-C score and diagnostic group. The findings remained significant after controlling for substance use disorders, antipsychotic medication and illness severity.

CONCLUSION

The results show a dose-dependent relationship between alcohol use and thinner cortex and ventricular expansion. The findings are present also at lower levels of alcohol consumption and do not differ between schizophrenia or bipolar disorder patients compared to healthy controls. Our results do not support previous findings of increased vulnerability for alcohol-related brain damage in severe mental illness.

Brain volume change in first-episode psychosis: an effect of antipsychotic medication independent of BMI change

OBJECTIVE

The effect of antipsychotic medication on brain structure remains unclear. Given the prevalence of weight gain as a side-effect, body mass index (BMI) change could be a confounder.

METHOD

Patients with first-episode psychosis (n = 78) and healthy controls (n = 119) underwent two 1.5T MRI scans with a 1-year follow-up interval. siena (fsl 5.0) was used to measure whole-brain volume change. Weight and height were measured at both time points. Antipsychotic medication use at baseline and follow-up was converted into chlorpromazine equivalent dose and averaged.

RESULTS

Patients did not show significantly larger brain volume loss compared with healthy controls. In the whole sample (n = 197), BMI change was negatively associated with brain volume change (β = -0.19, P = 0.008); there was no interaction effect of group. Among patients, higher antipsychotic medication dosage was associated with greater brain volume loss (β = -0.45, P < 0.001). This association was not affected by adjusting for BMI change.

CONCLUSION

Weight gain was related to brain volume reductions to a similar degree among patients and controls. Antipsychotic dosage-related reductions of brain volume were not confounded by BMI change. Generalizability to contexts involving severe weight gain needs to be established. Furthermore, disentangling effects of medication from illness severity remains a challenge.

Auditory Cortex Characteristics in Schizophrenia: Associations With Auditory Hallucinations

BACKGROUND

Neuroimaging studies have demonstrated associations between smaller auditory cortex volume and auditory hallucinations (AH) in schizophrenia. Reduced cortical volume can result from a reduction of either cortical thickness or cortical surface area, which may reflect different neuropathology. We investigate for the first time how thickness and surface area of the auditory cortex relate to AH in a large sample of schizophrenia spectrum patients.

METHODS

Schizophrenia spectrum (n = 194) patients underwent magnetic resonance imaging. Mean cortical thickness and surface area in auditory cortex regions (Heschl's gyrus [HG], planum temporale [PT], and superior temporal gyrus [STG]) were compared between patients with (AH+, n = 145) and without (AH-, n = 49) a lifetime history of AH and 279 healthy controls.

RESULTS

AH+ patients showed significantly thinner cortex in the left HG compared to AH- patients (d = 0.43, P = .0096). There were no significant differences between AH+ and AH- patients in cortical thickness in the PT or STG, or in auditory cortex surface area in any of the regions investigated. Group differences in cortical thickness in the left HG was not affected by duration of illness or current antipsychotic medication.

CONCLUSIONS

AH in schizophrenia patients were related to thinner cortex, but not smaller surface area of the left HG, a region which includes the primary auditory cortex. The results support that structural abnormalities of the auditory cortex underlie AH in schizophrenia.

Subcortical volumetric abnormalities in bipolar disorder

Considerable uncertainty exists about the defining brain changes associated with bipolar disorder (BD). Understanding and quantifying the sources of uncertainty can help generate novel clinical hypotheses about etiology and assist in the development of biomarkers for indexing disease progression and prognosis. Here we were interested in quantifying case-control differences in intracranial volume (ICV) and each of eight subcortical brain measures: nucleus accumbens, amygdala, caudate, hippocampus, globus pallidus, putamen, thalamus, lateral ventricles. In a large study of 1710 BD patients and 2594 healthy controls, we found consistent volumetric reductions in BD patients for mean hippocampus (Cohen's d=-0.232; P=3.50 × 10-7) and thalamus (d=-0.148; P=4.27 × 10-3) and enlarged lateral ventricles (d=-0.260; P=3.93 × 10-5) in patients. No significant effect of age at illness onset was detected. Stratifying patients based on clinical subtype (BD type I or type II) revealed that BDI patients had significantly larger lateral ventricles and smaller hippocampus and amygdala than controls. However, when comparing BDI and BDII patients directly, we did not detect any significant differences in brain volume. This likely represents similar etiology between BD subtype classifications. Exploratory analyses revealed significantly larger thalamic volumes in patients taking lithium compared with patients not taking lithium. We detected no significant differences between BDII patients and controls in the largest such comparison to date. Findings in this study should be interpreted with caution and with careful consideration of the limitations inherent to meta-analyzed neuroimaging comparisons.

Subcortical brain volume abnormalities in 2028 individuals with schizophrenia and 2540 healthy controls via the ENIGMA consortium

The profile of brain structural abnormalities in schizophrenia is still not fully understood, despite decades of research using brain scans. To validate a prospective meta-analysis approach to analyzing multicenter neuroimaging data, we analyzed brain MRI scans from 2028 schizophrenia patients and 2540 healthy controls, assessed with standardized methods at 15 centers worldwide. We identified subcortical brain volumes that differentiated patients from controls, and ranked them according to their effect sizes. Compared with healthy controls, patients with schizophrenia had smaller hippocampus (Cohen's d=-0.46), amygdala (d=-0.31), thalamus (d=-0.31), accumbens (d=-0.25) and intracranial volumes (d=-0.12), as well as larger pallidum (d=0.21) and lateral ventricle volumes (d=0.37). Putamen and pallidum volume augmentations were positively associated with duration of illness and hippocampal deficits scaled with the proportion of unmedicated patients. Worldwide cooperative analyses of brain imaging data support a profile of subcortical abnormalities in schizophrenia, which is consistent with that based on traditional meta-analytic approaches. This first ENIGMA Schizophrenia Working Group study validates that collaborative data analyses can readily be used across brain phenotypes and disorders and encourages analysis and data sharing efforts to further our understanding of severe mental illness.

No progressive brain changes during a 1-year follow-up of patients with first-episode psychosis

BACKGROUND

First-episode psychosis (FEP) patients show structural brain abnormalities. Whether the changes are progressive or not remain under debate, and the results from longitudinal magnetic resonance imaging (MRI) studies are mixed. We investigated if FEP patients showed a different pattern of regional brain structural change over a 1-year period compared with healthy controls, and if putative changes correlated with clinical characteristics and outcome.

METHOD

MRIs of 79 FEP patients [SCID-I-verified diagnoses: schizophrenia, psychotic bipolar disorder, or other psychoses, mean age 27.6 (s.d. = 7.7) years, 66% male] and 82 healthy controls [age 29.3 (s.d. = 7.2) years, 66% male] were acquired from the same 1.5 T scanner at baseline and 1-year follow-up as part of the Thematically Organized Psychosis (TOP) study, Oslo, Norway. Scans were automatically processed with the longitudinal stream in FreeSurfer that creates an unbiased within-subject template image. General linear models were used to analyse longitudinal change in a wide range of subcortical volumes and detailed thickness and surface area estimates across the entire cortex, and associations with clinical characteristics.

RESULTS

FEP patients and controls did not differ significantly in annual percentage change in cortical thickness or area in any cortical region, or in any of the subcortical structures after adjustment for multiple comparisons. Within the FEP group, duration of untreated psychosis, age at illness onset, antipsychotic medication use and remission at follow-up were not related to longitudinal brain change.

CONCLUSIONS

We found no significant longitudinal brain changes over a 1-year period in FEP patients. Our results do not support early progressive brain changes in psychotic disorders.

Impaired Verbal Learning Is Associated with Larger Caudate Volumes in Early Onset Schizophrenia Spectrum Disorders

Background

Both brain structural abnormalities and neurocognitive impairments are core features of schizophrenia. We have previously reported enlargements in subcortical brain structure volumes and impairment of neurocognitive functioning as measured by the MATRICS Cognitive Consensus Battery (MCCB) in early onset schizophrenia spectrum disorders (EOS). To our knowledge, no previous study has investigated whether neurocognitive performance and volumetric abnormalities in subcortical brain structures are related in EOS.

Methods

Twenty-four patients with EOS and 33 healthy controls (HC) were included in the study. Relationships between the caudate nucleus, the lateral and fourth ventricles volumes and neurocognitive performance were investigated with multivariate linear regression analyses. Intracranial volume, age, antipsychotic medication and IQ were included as independent predictor-variables.

Results

The caudate volume was negatively correlated with verbal learning performance uniquely in the EOS group (r=-.454, p=.034). There were comparable positive correlations between the lateral ventricular volume and the processing speed, attention and reasoning and problem solving domains for both the EOS patients and the healthy controls. Antipsychotic medication was related to ventricular enlargements, but did not affect the brain structure-function relationship.

Conclusion

Enlargement of the caudate volume was related to poorer verbal learning performance in patients with EOS. Despite a 32% enlargement of the lateral ventricles in the EOS group, associations to processing speed, attention and reasoning and problem solving were similar for both the EOS and the HC groups.

Brain structure characteristics in intellectually superior schizophrenia

The current study aims to fill a gap in the knowledge base by investigating the structural brain characteristics of individuals with schizophrenia and superior intellectual abilities. Subcortical volumes, cortical thickness and cortical surface area were examined in intellectually normal and intellectually superior participants with schizophrenia and their IQ-matched healthy controls, as well as in intellectually low schizophrenia participants. We replicated significant diagnostic group effects on hippocampal and ventricular size after correction for multiple comparisons. There were no statistically significant effects of intellectual level or of the interaction between diagnostic group and intellectual level. Effect sizes indicated that differences between schizophrenia and healthy control participants were of similar magnitude at both intellectual levels for all three types of morphological data. A secondary analysis within the schizophrenia group, including participants with low intellectual abilities, yielded numerical, but no statistically significant differences on any structural brain measure. The present findings indicate that the brain structure abnormalities in schizophrenia are present at all intellectual levels, and individuals with schizophrenia and superior intellectual abilities have brain structure abnormalities of the same magnitude as individuals with schizophrenia and normal intellectual abilities.

Common genetic variants influence human subcortical brain structures

The highly complex structure of the human brain is strongly shaped by genetic influences. Subcortical brain regions form circuits with cortical areas to coordinate movement, learning, memory and motivation, and altered circuits can lead to abnormal behaviour and disease. To investigate how common genetic variants affect the structure of these brain regions, here we conduct genome-wide association studies of the volumes of seven subcortical regions and the intracranial volume derived from magnetic resonance images of 30,717 individuals from 50 cohorts. We identify five novel genetic variants influencing the volumes of the putamen and caudate nucleus. We also find stronger evidence for three loci with previously established influences on hippocampal volume and intracranial volume. These variants show specific volumetric effects on brain structures rather than global effects across structures. The strongest effects were found for the putamen, where a novel intergenic locus with replicable influence on volume (rs945270; P = 1.08 × 10(-33); 0.52% variance explained) showed evidence of altering the expression of the KTN1 gene in both brain and blood tissue. Variants influencing putamen volume clustered near developmental genes that regulate apoptosis, axon guidance and vesicle transport. Identification of these genetic variants provides insight into the causes of variability in human brain development, and may help to determine mechanisms of neuropsychiatric dysfunction.

Normal birth weight variation is related to cortical morphology across the psychosis spectrum

BACKGROUND

Normal birth weight variation affects schizophrenia risk and cognitive performance in schizophrenia patients and healthy controls. Brain cortical anatomy is altered in psychotic disorders and in low birth weight subjects, but if birth weight variation relates to cortical morphology across the psychosis spectrum is not known.

METHODS

Magnetic Resonance Imaging brain scans and clinical-, neurocognitive-, and medical birth registry data were collected from 359 adults including patients with a DSM-IV diagnosis of schizophrenia (n = 90, mean age 29.4±10.2 [95% CI], 62% male), bipolar disorder (n = 79, age 29.4±11.8, 39% male) or other psychosis (n = 40, age 26.3±10.0, 56% male), and healthy controls (n = 140, age 30.8±12.0,53% male). We explored the relationship between whole-range birth weight variation and cortical surface area and thickness and their possible associations to cognitive performance.

RESULTS

Across all groups, lower birth weight was associated with smaller total surface area (t = 3.87, P = .0001), within specific regions of the temporal, parietal, and frontal cortex bilaterally. There were no associations between birth weight and cortical thickness, and no diagnosis by birth weight interaction effects on cortical thickness or surface area. Smaller cortical area (t = 2.50, P = .013) and lower birth weight (t = 2.53, P = .012) were significantly related to poorer working memory performance in all diagnostic groups except schizophrenia.

CONCLUSION

Birth weight relates to adult cortical surface area, but not cortical thickness, in patients across the psychosis spectrum and in healthy controls. Cortical area appears to be a diagnosis-independent general marker of early neurodevelopment, with a dose-response association to normal birth weight variation.

ZNF804A and cortical thickness in schizophrenia and bipolar disorder

ZNF804A SNP rs1344706 confers genome-wide risk for schizophrenia and bipolar disorder. Both disorders affect cortical thickness. To determine if single nucleotide polymorphisms (SNPs) across ZNF804A are associated with cortical thinning, we investigated 63 SNPs (including rs1344706) in 365 psychosis patients and healthy controls. Results show no significant associations.

A 5-year follow-up study of brain cortical and subcortical abnormalities in a schizophrenia cohort

BACKGROUND

Magnetic resonance imaging studies have demonstrated that patients with schizophrenia have thinner cortex in prefrontal and temporal brain regions, and enlarged lateral ventricles, compared to healthy subjects. Longitudinal studies have shown progressive brain tissue loss and ventricular dilatation among patients, predominantly in the early phase of the illness. Evidence for progression in more chronic phases of schizophrenia is less established.

METHODS

Measurements of cortical thickness, cortical volume and subcortical volumes were obtained from 52 patients with long-term treated schizophrenia and 63 healthy subjects who were scanned twice over five years. Differences in brain measurements across time and group were investigated using general linear models.

RESULTS

Compared to controls, patients had similar patterns of thinner cortex and smaller cortical volumes in prefrontal and temporal regions at both time points. In the follow-up interval regional cortical volumes decreased and lateral ventricle volumes increased in both groups. There was a trend level interaction effect of group and time for the right lateral ventricle, but not for cortical measurements. This effect was related to higher degree of negative symptoms at follow-up.

CONCLUSIONS

Regional differences in cortical thickness and volume between long-term treated patients with schizophrenia and healthy subjects are stable across five years, while right lateral ventricle volumes tend to increase more in the patients. The findings indicate that brain structure abnormalities found in schizophrenia are not progressive in the chronic stage of the disease, but that some progression in subcortical structures may be present in patients with poor outcome.

Effect of DISC1 SNPs on brain structure in healthy controls and patients with a history of psychosis

Disrupted-in-Schizophrenia-1 (DISC1) has been suggested as a susceptibility locus for a broad spectrum of psychiatric disorders. Risk variants have been associated with brain structural changes, which overlap alterations reported in schizophrenia and bipolar disorder patients. We used genome-wide genotyping data for a Norwegian sample of healthy controls (n = 171) and patients with a history of psychosis (n = 184), to investigate 61 SNPs in the DISC1 region for putative association with structural magnetic resonance imaging (sMRI) measures (hippocampal volume; mean cortical thickness; and total surface area, as well as cortical thickness and area divided into four lobar measures). SNP rs821589 was associated with mean temporal and total brain cortical thickness in controls (P(adjusted) = 0.009 and 0.02, respectively), but not in patients. SNPs rs11122319 and rs1417584 were associated with mean temporal cortical thickness in patients (P(adjusted) = 0.04 and 0.03, respectively), but not in controls, and both SNPs have previously been highly associated with DISC1 gene expression. There were significant genotype ×  case-control interactions. There was no significant association between SNPs and cortical area or hippocampal volume in controls, or with any of the structural measures in cases, after correction for multiple comparisons. In conclusion, DISC1 SNPs might impact brain structural variation, possibly differently in psychosis patients versus controls, but independent replication will be needed to confirm our findings.

Cortical folding in Broca's area relates to obstetric complications in schizophrenia patients and healthy controls

BACKGROUND

The increased occurrence of obstetric complications (OCs) in patients with schizophrenia suggests that alterations in neurodevelopment may be of importance to the aetiology of the illness. Abnormal cortical folding may reflect subtle deviation from normal neurodevelopment during the foetal or neonatal period. In the present study, we hypothesized that OCs would be related to cortical folding abnormalities in schizophrenia patients corresponding to areas where patients with schizophrenia display altered cortical folding when compared with healthy controls.

METHOD

In total, 54 schizophrenia patients and 54 healthy control subjects underwent clinical examination and magnetic resonance image scanning on a 1.5 T scanner. Information on OCs was collected from original birth records. An automated algorithm was used to calculate a three-dimensional local gyrification index (lGI) at numerous points across the cortical mantle.

RESULTS

In both schizophrenia patients and healthy controls, an increasing number of OCs was significantly related to lower lGI in the left pars triangularis (p<0.0005) in Broca's area. For five other anatomical cortical parcellations in the left hemisphere, a similar trend was demonstrated. No significant relationships between OCs and lGI were found in the right hemisphere and there were no significant case-control differences in lGI.

CONCLUSIONS

The reduced cortical folding in the left pars triangularis, associated with OCs in both patients and control subjects suggests that the cortical effect of OCs is caused by factors shared by schizophrenia patients and healthy controls rather than factors related to schizophrenia alone.

Cortical volume, surface area, and thickness in schizophrenia and bipolar disorder

BACKGROUND

Magnetic resonance imaging studies have shown that structural brain abnormalities are present in both schizophrenia and bipolar disorder. Most previous studies have focused on brain tissue volumes, but advances in neuroimaging data processing have made it possible to separate cortical area and cortical thickness. The purpose of the present study was to provide a more complete picture of cortical morphometric differences in schizophrenia and bipolar disorder, decomposing cortical volume into its constituent parts, cortical thickness and cortical area.

METHODS

We analyzed magnetic resonance imaging images from a sample of 173 patients with schizophrenia, 139 patients with bipolar disorder, and 207 healthy control subjects. Maps of cortical volume, area, and thickness across the continuous cortical surface were generated within groups and compared between the groups.

RESULTS

There were widespread reductions in cortical volume in schizophrenia relative to healthy control subjects and patients with bipolar disorder type I. These reductions were mainly driven by cortical thinning, but there were also cortical area reductions in more circumscribed regions, which contributed to the observed volume reductions.

CONCLUSIONS

The current surface-based methodology allows for a distinction between cortical thinning and reduction in cortical area and reveals that cortical thinning is the most important factor in volume reduction in schizophrenia. Cortical area reduction was not observed in bipolar disorder type I and may be unique to schizophrenia.

Common sequence variants in the major histocompatibility complex region associate with cerebral ventricular size in schizophrenia

BACKGROUND

Because of evidence from genetic linkage and genome-wide association studies, as well as suggested involvement of infection, the major histocompatibility complex (MHC) region on chromosome 6p21.3-22.1 has been implicated in the development of schizophrenia.

METHODS

Here, we investigated how gene variants across the MHC region are associated with brain structure in a large ethnically homogenous sample (n = 420), including patients with schizophrenia spectrum disorders and other severe mental illness and healthy control subjects.

RESULTS

We demonstrate highly significant associations between common gene markers in the MHC region and cerebral ventricular volume specifically in schizophrenia spectrum patients (uncorrected p values between 1.16 × 10⁻⁴ and 2.00 × 10⁻⁷). One single nucleotide polymorphism, rs2596532, survives Bonferroni correction for multiple testing across all single nucleotide polymorphisms and brain structure measures (adjusted p value 5.59 × 10⁻⁴).

CONCLUSIONS

The results indicate that MHC variants are implicated in characteristic brain abnormalities of schizophrenia.

Subcortical brain volumes relate to neurocognition in schizophrenia and bipolar disorder and healthy controls

BACKGROUND

Similar patterns of subcortical brain abnormalities and neurocognitive dysfunction have been demonstrated in schizophrenia and bipolar disorder, with more extensive findings in schizophrenia. It is unknown whether relationships between subcortical volumes and neurocognitive performance are similar or different between schizophrenia and bipolar disorder.

METHODS

MRI scans and neuropsychological test performance were obtained from 117 schizophrenia or 121 bipolar spectrum disorder patients and 192 healthy control subjects. Using the FreeSurfer software, volumes of 18 selected subcortical structures were automatically segmented and analyzed for relationships with results from 7 neurocognitive tests.

RESULTS

In schizophrenia, larger left ventricular volumes were related to poorer motor speed, and bilateral putamen volumes were related to poorer verbal learning, executive functioning and working memory performance. In bipolar disorder, larger left ventricular volumes were related to poorer motor speed and executive functioning. The relationship between left putamen volume and working memory was specific to schizophrenia. The relationships between left inferior lateral ventricles and motor speed and between right putamen volumes and executive functioning were similar in schizophrenia and bipolar disorder, and different from healthy controls. The results remained significant after corrections for use of antipsychotic medication. Significant structure-function relationships were also found when all subjects were combined into one group.

CONCLUSION

The present findings suggest that there are differences as well as similarities in subcortical structure/function relationships between patients with schizophrenia or bipolar disorder and healthy individuals. The observed differences further suggest that ventricular and putamen volume sizes may reflect severity of cognitive dysfunction in these disorders.

Cortical thickness and subcortical volumes in schizophrenia and bipolar disorder

BACKGROUND

Schizophrenia and bipolar disorder are severe psychiatric diseases with overlapping symptomatology. Widespread brain morphologic abnormalities, including cortical thinning and subcortical volume reductions, have been demonstrated in schizophrenia but it is unclear whether similar abnormalities are present in bipolar disorder. The purpose of this study was to compare cortical thickness and subcortical volumes in schizophrenia and bipolar disorder, to assess differences and similarities in cortical and subcortical brain structure.

METHODS

We analyzed magnetic resonance images from a sample of 173 patients with schizophrenia spectrum disorder, 139 patients with bipolar disorder, and 207 healthy control subjects. Cortical thickness was compared between the groups in multiple locations across the continuous cortical surface. Subcortical volumes were compared on a structure-by-structure basis.

RESULTS

There was widespread cortical thinning in schizophrenia compared with control subjects, in frontal, temporal, occipital, and smaller parietal regions. There was no cortical thinning in bipolar disorder compared with control subjects or in schizophrenia compared with bipolar disorder. However, the subgroup of patients with bipolar disorder Type 1 showed cortical thinning, primarily in the frontal lobes and superior temporal and temporoparietal regions. Both patient groups showed substantial subcortical volume reductions bilaterally in the hippocampus, the left thalamus, the right nucleus accumbens, the left cerebellar cortex, and the brainstem, along with substantial ventricular enlargements.

CONCLUSIONS

We found substantial overlap in the underlying brain morphologic abnormalities in schizophrenia and bipolar disorder in subcortical structures, and between schizophrenia and bipolar disorder Type 1 in the cerebral cortex.