[Show abstract][Hide abstract] ABSTRACT: White matter (WM) abnormalities have been reported in Bipolar Disorder (BD) patients, as well as in their non-BD relatives, both children and adults. Although it is considered an emerging vulnerability marker for BD, there are no studies investigating WM alterations in pediatric unmedicated patients and young healthy offspring. In this study, we evaluated the presence of WM alterations in 18 pediatric, non medicated BD patients, as well as in 18 healthy offspring of BD type I parents and 20 healthy controls. 3T DT-MRI data were acquired and scans were processed with tract-based spatial statistics to provide measures of fractional anisotropy and diffusivity. We found no significant differences in WM microstructure between BD patients, healthy offspring and healthy controls. Previous studies that reported WM alterations investigated older subjects, either on medication (BD patients) or with psychiatric diagnoses other than BD (unaffected offspring). Our findings highlight the importance of the understanding of disease ontogeny and brain development dynamics in the search for early vulnerability markers for psychiatric disorders.
[Show abstract][Hide abstract] ABSTRACT: Various functional magnetic resonance imaging studies addressed the effects of antidepressant drugs on brain functioning in healthy subjects; however, none specifically investigated positive mood changes to antidepressant drug. Sixteen subjects with no personal or family history of psychiatric disorders were selected from an ongoing 4-week open trial of small doses of clomipramine. Follow-up interviews documented clear positive treatment effects in six subjects, with reduced irritability and tension in social interactions, improved decision making, higher self-confidence and brighter mood. These subjects were then included in a placebo-controlled confirmatory trial and were scanned immediately after 4 weeks of clomipramine use and again 4 weeks after the last dose of clomipramine. The functional magnetic resonance imaging (fMRI) scans were run during emotion-eliciting stimuli. Repeated-measures analysis of variance of brain activity patterns showed significant interactions between group and treatment status during induced irritability (P<0.005 cluster-based) but not during happiness. Individuals displaying a positive subjective response do clomipramine had higher frontoparietal cortex activity during irritability than during happiness and neutral emotion, and higher temporo-parieto-occipital cortex activity during irritability than during happiness. We conclude that antidepressants not only induce positive mood responses but also act upon autobiographical recall of negative emotions.
[Show abstract][Hide abstract] ABSTRACT: Different lines of evidence suggest that mitochondrial dysfunction may be implicated in bipolar disorder (BD) pathophysiology. Mitochondrial electron transport chain (ETC) is a key target to evaluate mitochondrial function, but its activity has never been assessed in unmedicated BD or during mood episodes. Also, lithium has been shown to increase ETC gene expression/activity in preclinical models and in postmortem brains of BD subjects, but to date, no study has evaluated lithium's direct effects on ETC activity in vivo.
[Show abstract][Hide abstract] ABSTRACT: Background: The results of multiple studies on the association between antipsychotic use and structural brain changes in schizophrenia have been assessed only in qualitative literature reviews to date. We aimed to perform a meta-analysis of voxel-based morphometry (VBM) studies on this association to quantitatively synthesize the findings of these studies.
Methods: A systematic computerized literature search was carried out through MEDLINE/PubMed, EMBASE, ISI Web of Science, SCOPUS and PsycINFO databases aiming to identify all VBM studies addressing this question and meeting predetermined inclusion criteria. All studies reporting coordinates representing foci of structural brain changes associated with antipsychotic use were meta-analyzed by using the activation likelihood estimation technique, currently the most sophisticated and best-validated tool for voxel-wise meta-analysis of neuroimaging studies.
Results: Ten studies (five cross-sectional and five longitudinal) met the inclusion criteria and comprised a total of 548 individuals (298 patients on antipsychotic drugs and 250 controls). Depending on the methodologies of the selected studies, the control groups included healthy subjects, drug-free patients, or the same patients evaluated repeatedly in longitudinal comparisons (i.e., serving as their own controls). A total of 102 foci associated with structural alterations were retrieved. The meta-analysis revealed seven clusters of areas with consistent structural brain changes in patients on antipsychotics compared to controls. The seven clusters included four areas of relative volumetric decrease in the left lateral temporal cortex [Brodmann area (BA) 20], left inferior frontal gyrus (BA 44), superior frontal gyrus extending to the left middle frontal gyrus (BA 6), and right rectal gyrus (BA 11), and three areas of relative volumetric increase in the left dorsal anterior cingulate cortex (BA 24), left ventral anterior cingulate cortex (BA 24) and right putamen.
Conclusions: Our results identify the specific brain regions where possible associations between antipsychotic drug usage and structural brain changes in schizophrenia patients are more consistently reported. Additional longitudinal VBM studies including larger and more homogeneous samples of schizophrenia patients may be needed to further disentangle such alterations from those possibly linked to the intrinsic pathological progressive process in schizophrenia.
Keywords: Schizophrenia; Antipsychotics; Voxel-based morphometry; Magnetic resonance imaging; Neuroimaging
[Show abstract][Hide abstract] ABSTRACT: Objective:Children of parents with bipolar disorder (BD) are at heightened risk for developing mood and other psychiatric disorders. We proposed to evaluate the environment of families with at least one parent with BD type I (BDF) with affected offspring (aBDF) and unaffected offspring (uBDF) compared with control families without a history of DSM-IV Axis I disorder (CF).Method:We used the Family Environment Scale (FES) to evaluate 47 BDF (aBDF + uBDF) and 30 CF. Parents were assessed through the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I). Diagnosis of the offspring was determined through the Schedule for Affective Disorders and Schizophrenia for School-Age Children/Present and Lifetime Version (K-SADS-PL) interview.Results:There were statistically significant differences between aBDF, uBDF and CF in cohesion (p = 0.003), intellectual-cultural orientation (p = 0.01), active-recreational orientation (p = 0.007), conflict (p = 0.001), control (p = 0.01), moral-religious emphasis (p = 0.01) and organization (p = 0.001). The aBDF showed higher levels of control (p = 0.02) when compared to the uBDF.Conclusions:Families with a BD parent presented more dysfunctional interactions among members. Moreover, the presence of BD or other psychiatric disorders in the offspring of parents with BD is associated with higher levels of control. These results highlight the relevance of psychosocial interventions to improve resilience and family interactions.
Australian and New Zealand Journal of Psychiatry 10/2013; · 3.77 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The pathophysiology of Parkinson's disease (PD) has not yet been completely elucidated. However, during the past few years, significant progress has been made in understanding the intra- and extracellular mechanisms by which proteins such as alpha-synuclein and neuroinflammatory molecules may display impaired function and/or expression in PD. Recent developments in imaging techniques based on positron emission tomography (PET) and single photon emission computed tomography (SPECT) now allow the non-invasive tracking of such molecular targets of known relevance to PD in vivo. This article summarizes recent PET and SPECT studies of new radiopharmaceuticals and discusses their potential role and perspectives for use in the fields of new drug development and early diagnosis for PD, as well to aid in differential diagnosis and monitoring of the progression of PD.
[Show abstract][Hide abstract] ABSTRACT: Background: In recent years, growing concerns about the effects of cannabis use on mental health have renewed interest in cannabis research. In particular, there has been a marked increase in the number of neuroimaging studies of the effects of cannabinoids. We conducted a systematic review to assess the impact of acute cannabis exposure on brain function in humans and in experimental animals. Methods: Papers published until June 2012 were included from EMBASE, Medline, PubMed and LILACS databases following a comprehensive search strategy and pre-determined set of criteria for article selection. Only pharmacological challenge studies involving the acute experimental administration of cannabinoids in occasional or naive cannabis users, and naive animals were considered. Results: Two hundred and twenty-four studies were identified, of which 45 met our inclusion criteria. Twenty-four studies were in humans and 21 in animals. Most comprised studies of the acute effects of cannabinoids on brain functioning in the context of either resting state activity or activation during cognitive paradigms. In general, THC and CBD had opposite neurophysiological effects. There were also a smaller number of neurochemical imaging studies: overall, these did not support a central role for increased dopaminergic activity in THC-induced psychosis. There was a considerable degree of methodological heterogeneity in the imaging literature reviewed. Conclusion: Functional neuroimaging studies have provided extensive evidence for the acute modulation of brain function by cannabinoids, but further studies are needed in order to understand the neural mechanisms underlying these effects. Future studies should also consider the need for more standardised methodology and the replication of findings.
Current pharmaceutical design 06/2013; · 4.41 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In this article, the authors aim to present a critical review of recent MRI studies addressing white matter (WM) abnormalities in Alzheimer's disease (AD) and mild cognitive impairment (MCI), by searching PubMed and reviewing MRI studies evaluating subjects with AD or MCI using WM volumetric methods, diffusion tensor imaging and assessment of WM hyperintensities. Studies have found that, compared with healthy controls, AD and MCI samples display WM volumetric reductions and diffusion tensor imaging findings suggestive of reduced WM integrity. These changes affect complex networks relevant to episodic memory and other cognitive processes, including fiber connections that directly link medial temporal structures and the corpus callosum. Abnormalities in cortico-cortical and cortico-subcortical WM interconnections are associated with an increased risk of progression from MCI to dementia. It can be concluded that WM abnormalities are detectable in early stages of AD and MCI. Degeneration of WM networks causes disconnection among neural cells and the degree of such changes is related to cognitive decline.
Expert Review of Neurotherapeutics 05/2013; 13(5):483-93. · 2.96 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The relationship between major depressive disorder with psychotic (MDDP) features and schizophrenia has long been recognized, and the neurobiological boundaries between these disorders can nowadays be investigated using neuroimaging techniques. This article provides a critical review of such studies, addressing how they support a dimensional approach to the nosology and pathophysiology of psychotic disorders. A proportion of neuroimaging studies carried out to date indicate that MDDP subjects display structural and functional abnormalities in some brain regions specifically implicated in the pathophysiology of mood disorders, such as the subgenual cingulate cortex. This reinforces the validity of the classification of MDDP in proximity to major depression without psychosis. There is some neuroimaging evidence that MDDP may be associated with additional brain abnormalities relative to nonpsychotic major depression although less prominently in comparison with findings from the neuroimaging literature on schizophrenia. Brain regions seen as critical both to emotional processing and to models of psychotic symptoms, such as the hippocampus, insula, and lateral prefrontal cortex, have been implicated in separate neuroimaging investigations of either schizophrenia or major depression, as well as in some studies that directly compared depressed patients with and without psychotic features. These brain regions are key targets for future studies designed to validate imaging phenotypes more firmly associated with MDDP, as well as to investigate the relationship between these phenotypes and possible etiological influences for MDDP.
[Show abstract][Hide abstract] ABSTRACT: Objective: Many psychophysiological studies investigate whether psychopaths present low levels of electrodermal activity (EDA). However, despite evidence that varying degrees of psychopathy are normally distributed in the population, there is a paucity of EDA studies evaluating dimensionally. Moreover, although lack of empathy is a cornerstone of psychopathy, there has been a lack of studies using pictures of empathic emotional content to assess psychophysiological responses. Method: We studied a population of young male delinquents (n = 30) from a detention center, using the Psychopathy Checklist Revised (PCL-R) to determine if higher levels of psychopathy were related to lesser degrees of EDA in response to emotion-eliciting pictures of empathic content. Results: There were significant correlations (p < 0.05) between latency and peak of EDA responses to unpleasant pictures and factor 1 scores, as well as between lability of EDA responses and factor 2 scores. Conclusion: These results extend previous findings indicating direct relationship between EDA and psychopathy, and suggest that separate investigations of the two PCL-R factors have the potential to unravel more complex relationships between EDA and psychopathy. Also, by demonstrating such associations using emotion-provoking stimuli with empathic content, our results provide a link between levels of psychopathy and biological indices of empathic detachment.
[Show abstract][Hide abstract] ABSTRACT: Nearly one-third of patients with obsessive-compulsive disorder (OCD) fail to respond to adequate therapeutic approaches such as serotonin reuptake inhibitors and/or cognitive-behavioral therapy (CBT). This study investigated structural magnetic resonance imaging (MRI) correlates as potential pre-treatment brain markers to predict treatment response in treatment-naïve OCD patients randomized between trials of fluoxetine or CBT. Treatment-naïve OCD patients underwent structural MRI scans before randomization to a 12-week clinical trial of either fluoxetine or group-based CBT. Voxel-based morphometry was used to identify correlations between pretreatment regional gray matter volume and changes in symptom severity on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). Brain regional correlations of treatment response differed between treatment groups. Notably, symptom improvement in the fluoxetine treatment group (n=14) was significantly correlated with smaller pretreatment gray matter volume within the right middle lateral orbitofrontal cortex (OFC), whereas symptom improvement in the CBT treatment group (n=15) was significantly correlated with larger pretreatment gray matter volume within the right medial prefrontal cortex (mPFC). No significant a priori regional correlations of treatment response were identified as common between the two treatment groups when considering the entire sample (n=29). These findings suggest that pretreatment gray matter volumes of distinct brain regions within the lateral OFC and mPFC were differentially correlated to treatment response to fluoxetine versus CBT in OCD patients. This study further implicates the mPFC in the fear/anxiety extinction process and stresses the importance of lateral portions of the OFC in mediating fluoxetine's effectiveness in OCD. Clinical registration information: http://clinicaltrials.gov-NCT00680602.
European neuropsychopharmacology: the journal of the European College of Neuropsychopharmacology 07/2012; · 3.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The occurrence of white matter (WM) abnormalities in psychotic disorders has been suggested by several studies investigating brain pathology and diffusion tensor measures, but evidence assessing regional WM morphometry is still scarce and conflicting. In the present study, 122 individuals with first-episode psychosis (FEP) (62 fulfilling criteria for schizophrenia/schizophreniform disorder, 26 psychotic bipolar I disorder, and 20 psychotic major depressive disorder) underwent magnetic resonance imaging, as well as 94 epidemiologically recruited controls. Images were processed with the Statistical Parametric Mapping (SPM2) package, and voxel-based morphometry was used to compare groups (t-test) and subgroups (ANOVA). Initially, no regional WM abnormalities were observed when both groups (overall FEP group versus controls) and subgroups (i.e., schizophrenia/schizophreniform, psychotic bipolar I disorder, psychotic depression, and controls) were compared. However, when the voxelwise analyses were repeated excluding subjects with comorbid substance abuse or dependence, the resulting statistical maps revealed a focal volumetric reduction in right frontal WM, corresponding to the right middle frontal gyral WM/third subcomponent of the superior longitudinal fasciculus, in subjects with schizophrenia/schizophreniform disorder (n=40) relative to controls (n=89). Our results suggest that schizophrenia/schizophreniform disorder is associated with right frontal WM volume decrease at an early course of the illness.
Psychiatry Research 07/2012; 202(3):198-205. · 2.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cardiovascular risk factors (CVRF) possibly contribute to the emergence of Alzheimer's disease (AD). Fluorodeoxyglucose-positron emission tomography (FDG-PET) has been widely used to demonstrate specific patterns of reduced cerebral metabolic rates of glucose (CMRgl) in subjects with AD and in non-demented carriers of the apolipoprotein ε4 (APOE ε4) allele, the major genetic risk factor for AD. However, functional neuroimaging studies investigating the impact of CVRF on cerebral metabolism have been scarce to date. The present FDG-PET study investigated 59 cognitively preserved elderlies divided into three groups according to their cardiovascular risk based on the Framingham 10-year risk Coronary Heart Disease Risk Profile (low-, medium-, and high-risk) to examine whether different levels of CVRF would be associated with reduced CMRgl, involving the same brain regions affected in early stages of AD. Functional imaging data were corrected for partial volume effects to avoid confounding effects due to regional brain atrophy, and all analyses included the presence of the APOE ε4 allele as a confounding covariate. Significant cerebral metabolism reductions were detected in the high-risk group when compared to the low-risk group in the left precuneus and posterior cingulate gyrus. This suggests that findings of brain hypometabolism similar to those seen in subjects with AD can be detected in association with the severity of cardiovascular risk in cognitively preserved individuals. Thus, a greater knowledge about how such factors influence brain functioning in healthy subjects over time may provide important insigths for the future development of strategies aimed at delaying or preventing the vascular-related triggering of pathologic brain changes in the AD.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Neurodevelopmental alterations have been described inconsistently in psychosis probably because of lack of standardization among studies. The aim of this study was to conduct the first longitudinal and population-based magnetic resonance imaging (MRI) evaluation of the presence and size of the cavum septum pellucidum (CSP) and adhesio interthalamica (AI) in a large sample of patients with first-episode psychosis (FEP).MethodFEP patients (n=122) were subdivided into schizophrenia (n=62), mood disorders (n=46) and other psychosis (n=14) groups and compared to 94 healthy next-door neighbour controls. After 13 months, 80 FEP patients and 52 controls underwent a second MRI examination. RESULTS: We found significant reductions in the AI length in schizophrenia FEP in comparison with the mood disorders and control subgroups (longer length) at the baseline assessment, and no differences in any measure of the CSP. By contrast, there was a diagnosis×time interaction for the CSP length, with a more prominent increase for this measure in the psychosis group. There was an involution of the AI length over time for all groups but no diagnosis×time interaction. CONCLUSIONS: Our findings suggest that the CSP per se may not be linked to the neurobiology of emerging psychotic disorders, although it might be related to the progression of the disease. However, the fact that the AI length was shown to be shorter at the onset of the disorder supports the neurodevelopmental model of schizophrenia and indicates that an alteration in this grey matter junction may be a risk factor for developing psychosis.
Psychological Medicine 04/2012; · 5.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Previous cross-sectional magnetic resonance imaging (MRI) studies of healthy aging in young adults have indicated the presence of significant inverse correlations between age and gray matter volumes, although not homogeneously across all brain regions. However, such cross-sectional studies have important limitations and there is a scarcity of detailed longitudinal MRI studies with repeated measures obtained in the same individuals in order to investigate regional gray matter changes during short periods of time in non-elderly healthy adults. In the present study, 52 healthy young adults aged 18 to 50 years (27 males and 25 females) were followed with repeated MRI acquisitions over approximately 15 months. Gray matter volumes were compared between the two times using voxel-based morphometry, with the prediction that volume changes would be detectable in the frontal lobe, temporal neocortex and hippocampus. Voxel-wise analyses showed significant (P < 0.05, family-wise error corrected) relative volume reductions of gray matter in two small foci located in the right orbitofrontal cortex and left hippocampus. Separate comparisons for males and females showed bilateral gray matter relative reductions in the orbitofrontal cortex over time only in males. We conclude that, in non-elderly healthy adults, subtle gray matter volume alterations are detectable after short periods of time. This underscores the dynamic nature of gray matter changes in the brain during adult life, with regional volume reductions being detectable in brain regions that are relevant to cognitive and emotional processes.
Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas / Sociedade Brasileira de Biofisica ... [et al.] 03/2012; 45(6):516-23. · 1.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Serotonin reuptake inhibitors and cognitive-behavior therapy (CBT) are considered first-line treatments for obsessive-compulsive disorder (OCD). However, little is known about their modulatory effects on regional brain morphology in OCD patients. We sought to document structural brain abnormalities in treatment-naive OCD patients and to determine the effects of pharmacological and cognitive-behavioral treatments on regional brain volumes. Treatment-naive patients with OCD (n=38) underwent structural magnetic resonance imaging scan before and after a 12-week randomized clinical trial with either fluoxetine or group CBT. Matched-healthy controls (n=36) were also scanned at baseline. Voxel-based morphometry was used to compare regional gray matter (GM) volumes of regions of interest (ROIs) placed in the orbitofrontal, anterior cingulate and temporolimbic cortices, striatum, and thalamus. Treatment-naive OCD patients presented smaller GM volume in the left putamen, bilateral medial orbitofrontal, and left anterior cingulate cortices than did controls (p<0.05, corrected for multiple comparisons). After treatment with either fluoxetine or CBT (n=26), GM volume abnormalities in the left putamen were no longer detectable relative to controls. ROI-based within-group comparisons revealed that GM volume in the left putamen significantly increased (p<0.012) in fluoxetine-treated patients (n=13), whereas no significant GM volume changes were observed in CBT-treated patients (n=13). This study supports the involvement of orbitofronto/cingulo-striatal loops in the pathophysiology of OCD and suggests that fluoxetine and CBT may have distinct neurobiological mechanisms of action.
Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology 02/2012; 37(3):734-45. · 8.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Functional brain variability has been scarcely investigated in cognitively healthy elderly subjects, and it is currently debated whether previous findings of regional metabolic variability are artifacts associated with brain atrophy. The primary purpose of this study was to test whether there is regional cerebral age-related hypometabolism specifically in later stages of life.
MR imaging and FDG-PET data were acquired from 55 cognitively healthy elderly subjects, and voxel-based linear correlations between age and GM volume or regional cerebral metabolism were conducted by using SPM5 in images with and without correction for PVE. To investigate sex-specific differences in the pattern of brain aging, we repeated the above voxelwise calculations after dividing our sample by sex.
Our analysis revealed 2 large clusters of age-related metabolic decrease in the overall sample, 1 in the left orbitofrontal cortex and the other in the right temporolimbic region, encompassing the hippocampus, the parahippocampal gyrus, and the amygdala. The division of our sample by sex revealed significant sex-specific age-related metabolic decrease in the left temporolimbic region of men and in the left dorsolateral frontal cortex of women. When we applied atrophy correction to our PET data, none of the above-mentioned correlations remained significant.
Our findings suggest that age-related functional brain variability in cognitively healthy elderly individuals is largely secondary to the degree of regional brain atrophy, and the findings provide support to the notion that appropriate PVE correction is a key tool in neuroimaging investigations.
American Journal of Neuroradiology 02/2011; 32(3):560-5. · 3.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Some neuroimaging studies have supported the hypothesis of progressive brain changes after a first episode of psychosis. We aimed to determine whether (i) first-episode psychosis patients would exhibit more pronounced brain volumetric changes than controls over time and (ii) illness course/treatment would relate to those changes.
Longitudinal regional grey matter volume and ventricle:brain ratio differences between 39 patients with first-episode psychosis (including schizophrenia and schizophreniform disorder) and 52 non-psychotic controls enrolled in a population-based case-control study.
While there was no longitudinal difference in ventricle:brain ratios between first-episode psychosis subjects and controls, patients exhibited grey matter volume changes, indicating a reversible course in the superior temporal cortex and hippocampus compared with controls. A remitting course was related to reversal of baseline temporal grey matter deficits.
Our findings do not support the hypothesis of brain changes indicating a progressive course in the initial phase of psychosis. Rather, some brain volume abnormalities may be reversible, possibly associated with a better illness course.
Psychological Medicine 12/2010; 41(8):1677-89. · 5.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this article is to propose an integrated framework for extracting and describing patterns of disorders from medical images using a combination of linear discriminant analysis and active contour models.
A multivariate statistical methodology was first used to identify the most discriminating hyperplane separating two groups of images (from healthy controls and patients with schizophrenia) contained in the input data. After this, the present work makes explicit the differences found by the multivariate statistical method by subtracting the discriminant models of controls and patients, weighted by the pooled variance between the two groups. A variational level-set technique was used to segment clusters of these differences. We obtain a label of each anatomical change using the Talairach atlas.
In this work all the data was analysed simultaneously rather than assuming a priori regions of interest. As a consequence of this, by using active contour models, we were able to obtain regions of interest that were emergent from the data. The results were evaluated using, as gold standard, well-known facts about the neuroanatomical changes related to schizophrenia. Most of the items in the gold standard was covered in our result set.
We argue that such investigation provides a suitable framework for characterising the high complexity of magnetic resonance images in schizophrenia as the results obtained indicate a high sensitivity rate with respect to the gold standard.
Artificial intelligence in medicine 06/2010; 49(2):105-15. · 1.65 Impact Factor