A manual and automated MRI study of anterior cingulate and orbito-frontal cortices, and caudate nucleus in obsessive-compulsive disorder: comparison with healthy controls and patients with schizophrenia

Enhanced cognitive flexibility and phasic striatal dopamine dynamics in a mouse model of low striatal tonic dopamine

The catecholamine neuromodulators dopamine and norepinephrine are implicated in motor function, motivation, and cognition. Although roles for striatal dopamine in these aspects of behavior are well established, the specific roles for cortical catecholamines in regulating striatal dopamine dynamics and behavior are less clear. We recently showed that elevating cortical dopamine but not norepinephrine suppresses hyperactivity in dopamine transporter knockout (DAT-KO) mice, which have elevated striatal dopamine levels. In contrast, norepinephrine transporter knockout (NET-KO) mice have a phenotype distinct from DAT-KO mice, as they show elevated extracellular cortical catecholamines but reduced baseline striatal dopamine levels. Here we evaluated the consequences of altered catecholamine levels in NET-KO mice on cognitive flexibility and striatal dopamine dynamics. In a probabilistic reversal learning task, NET-KO mice showed enhanced reversal learning, which was consistent with larger phasic dopamine transients (dLight) in the dorsomedial striatum (DMS) during reward delivery and reward omission, compared to WT controls. Selective depletion of dorsal medial prefrontal cortex (mPFC) norepinephrine in WT mice did not alter performance on the reversal learning task but reduced nestlet shredding. Surprisingly, NET-KO mice did not show altered breakpoints in a progressive ratio task, suggesting intact food motivation. Collectively, these studies show novel roles of cortical catecholamines in the regulation of tonic and phasic striatal dopamine dynamics and cognitive flexibility, updating our current views on dopamine regulation and informing future therapeutic strategies to counter multiple psychiatric disorders.

Cortical Thickness of the Orbitofrontal Cortex in Patients with Alcohol Use Disorder

Aims: In the present study, it was hypothesised that compared to healthy control subjects, significant differences in the cortical thickness of the orbitofrontal cortex (OFC) region of the brain, which is relevant to both impulsivity and decision making, would be identified. Methods: The subject groups included in the study were composed of 15 individuals who met the criteria for alcohol use disorder, according to the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM 5) diagnostic criteria based on the Structured Clinical Interview for DSM 5 (SCID), and were admitted to the Firat University School of Medicine Department of Psychiatry or were hospitalised, and 17 healthy control comparisons were made. The volumes of and cortical thickness of the OFC were measured in the subjects. Results: It was found that patients with alcohol use disorder had reduced volumes of the OFC bilaterally and a thinner cortical thickness of the same region bilaterally compared to those of the healthy control comparisons. Conclusions: Consequently, it is suggested that the OFC region of the brain appears to be statistically significantly smaller in patients with alcohol use disorder, both in terms of cortical thickness and volume, compared to healthy controls. Future research should focus on the status of these relationships longitudinally and should assess the causality of the association with the treatment response.

A significant, functional and replicable risk KTN1 variant block for schizophrenia

Cortical and subcortical structural alteration has been extensively reported in schizophrenia, including the unusual expansion of gray matter volumes (GMVs) of basal ganglia (BG), especially putamen. Previous genome-wide association studies pinpointed kinectin 1 gene (KTN1) as the most significant gene regulating the GMV of putamen. In this study, the role of KTN1 variants in risk and pathogenesis of schizophrenia was explored. A dense set of SNPs (n = 849) covering entire KTN1 was analyzed in three independent European- or African-American samples (n = 6704) and one mixed European and Asian Psychiatric Genomics Consortium sample (n = 56,418 cases vs. 78,818 controls), to identify replicable SNP-schizophrenia associations. The regulatory effects of schizophrenia-associated variants on the KTN1 mRNA expression in 16 cortical or subcortical regions in two European cohorts (n = 138 and 210, respectively), the total intracranial volume (ICV) in 46 European cohorts (n = 18,713), the GMVs of seven subcortical structures in 50 European cohorts (n = 38,258), and the surface areas (SA) and thickness (TH) of whole cortex and 34 cortical regions in 50 European cohorts (n = 33,992) and eight non-European cohorts (n = 2944) were carefully explored. We found that across entire KTN1, only 26 SNPs within the same block (r2 > 0.85) were associated with schizophrenia across ≥ 2 independent samples (7.5 × 10-5 ≤ p ≤ 0.048). The schizophrenia-risk alleles, which increased significantly risk for schizophrenia in Europeans (q < 0.05), were all minor alleles (f < 0.5), consistently increased (1) the KTN1 mRNA expression in 12 brain regions significantly (5.9 × 10-12 ≤ p ≤ 0.050; q < 0.05), (2) the ICV significantly (6.1 × 10-4 ≤ p ≤ 0.008; q < 0.05), (3) the SA of whole (9.6 × 10-3 ≤ p ≤ 0.047) and two regional cortices potentially (2.5 × 10-3 ≤ p ≤ 0.042; q > 0.05), and (4) the TH of eight regional cortices potentially (0.006 ≤ p ≤ 0.050; q > 0.05), and consistently decreased (1) the BG GMVs significantly (1.8 × 10-19 ≤ p ≤ 0.050; q < 0.05), especially putamen GMV (1.8 × 10-19 ≤ p ≤ 1.0 × 10-4; q < 0.05, (2) the SA of four regional cortices potentially (0.010 ≤ p ≤ 0.048), and (3) the TH of four regional cortices potentially (0.015 ≤ p ≤ 0.049) in Europeans. We concluded that we identified a significant, functional, and robust risk variant block covering entire KTN1 that might play a critical role in the risk and pathogenesis of schizophrenia.

Subcortical shape in pediatric and adult obsessive-compulsive disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) implicates alterations in cortico-striato-thalamo-cortical and fronto-limbic circuits. Building on prior structural findings, this is the largest study to date examining subcortical surface morphometry in OCD.

METHODS

Structural magnetic resonance imaging data were collected from 200 participants across development (5-55 years): 28 youth and 75 adults with OCD and 27 psychiatrically healthy youth and 70 adults. General linear models were used to assess group differences and group-by-age interactions on subcortical shape (FSL FIRST).

RESULTS

Compared to healthy participants, those with OCD exhibited surface expansions on the right nucleus accumbens and inward left amygdala deformations, which were associated with greater OCD symptom severity ([Children's] Yale-Brown Obsessive-Compulsive Scale). Group-by-age interactions indicated that accumbens group differences were driven by younger participants and that right pallidum shape was associated inversely with age in healthy participants, but not in participants with OCD. No differences in the shape of other subcortical regions or in volumes (FreeSurfer) were detected in supplementary analyses.

CONCLUSIONS

This study is the largest to date examining subcortical shape in OCD and the first to do so across the developmental spectrum. NAcc and amygdala shape deformation builds on extant neuroimaging findings and suggests subtle, subregional alterations beyond volumetric findings. Results shed light on morphometric alterations in OCD, informing current pathophysiological models.

Accelerated Brain Aging in Patients With Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) may be accompanied by an accelerated structural decline of the brain with age compared to healthy controls (HCs); however, this has yet to be proven. To answer this question, we built a brain age prediction model using mean gray matter volumes of each brain region as features, which were obtained by voxel-based morphometry derived from T1-weighted MRI scans. The prediction model was built using two Chinese Han datasets (dataset 1, N = 106 for HCs and N = 90 for patients with OCD; dataset 2, N = 270 for HCs) to evaluate its performance. Then, a new prediction model was trained using data for HCs in dataset 1 and applied to patients with OCD to investigate the brain aging trajectory. The brain-predicted age difference (brain-PAD) scores, defined as the difference between predicted brain age and chronological age, were calculated for all participants and compared between patients with matched HCs in dataset 1. It was demonstrated that the prediction model performs consistently across different datasets. Patients with OCD presented higher brain-PAD scores than matched HCs, suggesting that patients with OCD presented accelerated brain aging. In addition, brain-PAD scores were negatively correlated with the duration of illness, suggesting that brain-PAD scores might capture progressive structural brain changes. These results identified accelerated brain aging in patients with OCD for the first time and deepened our understanding of the pathogenesis of OCD.

Comparison of resting-state spontaneous brain activity between treatment-naive schizophrenia and obsessive-compulsive disorder

BACKGROUND

Schizophrenia (SZ) and obsessive-compulsive disorder (OCD) share many demographic characteristics and severity of clinical symptoms, genetic risk factors, pathophysiological underpinnings, and brain structure and function. However, the differences in the spontaneous brain activity patterns between the two diseases remain unclear. Here this study aimed to compare the features of intrinsic brain activity in treatment-naive participants with SZ and OCD and to explore the relationship between spontaneous brain activity and the severity of symptoms.

METHODS

In this study, 22 treatment-naive participants with SZ, 27 treatment-naive participants with OCD, and sixty healthy controls (HC) underwent a resting-state functional magnetic resonance imaging (fMRI) scan. The amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo) and degree of centrality (DC) were performed to examine the intrinsic brain activity of participants. Additionally, the relationships among spontaneous brain activity, the severity of symptoms, and the duration of illness were explored in SZ and OCD groups.

RESULTS

Compared with SZ group and HC group, participants with OCD had significantly higher ALFF in the right angular gyrus and the left middle frontal gyrus/precentral gyrus and significantly lower ALFF in the left superior temporal gyrus/insula/rolandic operculum and the left postcentral gyrus, while there was no significant difference in ALFF between SZ group and HC group. Compared with HC group, lower ALFF in the right supramarginal gyrus/inferior parietal lobule and lower DC in the right lingual gyrus/calcarine fissure and surrounding cortex of the two patient groups, higher ReHo in OCD group and lower ReHo in SZ group in the right angular gyrus/middle occipital gyrus brain region were documented in the present study. DC in SZ group was significantly higher than that in HC group in the right inferior parietal lobule/angular gyrus, while there were no significant DC differences between OCD group and HC group. In addition, ALFF in the left postcentral gyrus were positively correlated with positive subscale score (r = 0.588, P = 0.013) and general psychopathology subscale score (r = 0.488, P = 0.047) respectively on the Positive and Negative Syndrome Scale (PANSS) in SZ group. ALFF in the left superior temporal gyrus/insula/rolandic operculum of participants with OCD were positively correlated with compulsion subscale score (r = 0.463, P = 0.030) on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). The longer the illness duration in SZ group, the smaller the ALFF of the left superior temporal gyrus/insula/rolandic operculum (Rho = 0.-492, P = 0.020). The longer the illness duration in OCD group, the higher the ALFF of the right supramarginal gyrus/inferior parietal lobule (Rho = 0.392, P = 0.043) and the left postcentral gyrus (Rho = 0.385, P = 0.048), and the lower the DC of the right inferior parietal lobule/angular gyrus (Rho = - 0.518, P = 0.006).

CONCLUSION

SZ and OCD show some similarities in spontaneous brain activity in parietal and occipital lobes, but exhibit different patterns of spontaneous brain activity in frontal, temporal, parietal, occipital, and insula brain regions, which might imply different underlying neurobiological mechanisms in the two diseases. Compared with OCD, SZ implicates more significant abnormalities in the functional connections among brain regions.

Topographic volume-standardization atlas of the human brain

Specific anatomical patterns are seen in various diseases affecting the brain. Clinical studies on the topography of pathologies are often limited by the absence of a normalization of the prevalence of pathologies to the relative volume of the affected anatomical structures. A comprehensive reference on the relative volumes of clinically relevant anatomical structures serving for such a normalization, is currently lacking. The analyses are based on anatomical high-resolution three-dimensional T1-weighted magnetic resonance imaging data of 30 healthy Caucasian volunteers, including 14 females (mean age 37.79 years, SD 13.04) and 16 males (mean age 38.31 years, SD 16.91). Semi-automated anatomical segmentation was used, guided by a neuroanatomical parcellation algorithm differentiating 96 structures. Relative volumes were derived by normalizing parenchymal structures to the total individual encephalic volume and ventricular segments to the total individual ventricular volume. The present investigation provides the absolute and relative volumes of 96 anatomical parcellation units of the human encephalon. A larger absolute volume in males than in females is found for almost all parcellation units. While parenchymal structures display a trend towards decreasing volumes with increasing age, a significant inverse effect is seen with the ventricular system. The variances in volumes as well as the effects of gender and age are given for each structure before and after normalization. The provided atlas constitutes an anatomically detailed and comprehensive analysis of the absolute and relative volumes of the human encephalic structures using a clinically oriented parcellation algorithm. It is intended to serve as a reference for volume-standardization in clinical studies on the topographic prevalence of pathologies.

Antisaccade task performance in obsessive-compulsive disorder and its clinical correlates

OBJECTIVE

Obsessive-Compulsive Disorder (OCD) is characterized by abnormalities in the cortico-striato-thalamo-cortical (CSTC) circuitry of the brain. Antisaccade eye movement tasks measure aspects of the voluntary control of behaviour that are sensitive to CSTC circuitry dysfunction.

METHOD

In this study, we examined antisaccade eye movement parameters of OCD patients in comparison with healthy controls (HC). In addition, we also examined the relationship between the antisaccade eye movement parameters and the severity of OCD. Antisaccade performance among right handed OCD patients (N = 65) was compared to matched right handed HC (N = 57). Eye tracking data during the task performance were collected using an Eye-Link eye-tracker at 1000-Hz sampling rate. OCD symptom severity was evaluated using Yale-Brown obsessive compulsive scale.

RESULTS

The antisaccade error percentage was significantly greater in OCD patients than HC (p < 0.001). In addition, OCD patients had less accurate final eye position compared to HC (p < 0.001). There were no significant correlation between antisaccade parameters and OCD severity measures.

CONCLUSION

Deficient performance in antisaccade task supports CSTC abnormality in OCD and this appears to be independent of the illness severity. Examining this in remitted participants with OCD and in unaffected first degree relatives could help ascertaining their endophenotype validity.

Comorbidity in Schizophrenia: Conceptual Issues and Clinical Management

Schizophrenia is a complex psychiatric disorder that affects cognitive, perceptual, and emotional functioning. The currently available evidence suggests heterogenous intertwining of biological and psychosocial etio-pathogeneses. Clinical and research interests in the comorbidity issues of schizophrenia were borne out of the real-world clinical challenges that patients often present with multiple coexisting psychopathologies as well as comorbid medical conditions. The recent DSM-5 shift toward a symptom dimensional-based perspective, the NIMH Research Domain Criteria (RDoC) initiative to examine biopsychosocial pathogeneses in mental illness, and the FDA's emphasis on real world-based clinical trial criterion all have promoted a shift in clinical research that has facilitated understanding and treatment of comorbidity in schizophrenia. This emerging conceptual shift as well as pharmacological developments that address the multidimensional pathogeneses in schizophrenia may pave the way for a better understanding and treatment.

Central norepinephrine transmission is required for stress-induced repetitive behavior in two rodent models of obsessive-compulsive disorder

RATIONALE

Obsessive-compulsive disorder (OCD) is characterized by repetitive behaviors exacerbated by stress. Many OCD patients do not respond to available pharmacotherapies, but neurosurgical ablation of the anterior cingulate cortex (ACC) can provide symptomatic relief. Although the ACC receives noradrenergic innervation and expresses adrenergic receptors (ARs), the involvement of norepinephrine (NE) in OCD has not been investigated.

OBJECTIVE

To determine the effects of genetic or pharmacological disruption of NE neurotransmission on marble burying (MB) and nestlet shredding (NS), two animal models of OCD.

METHODS

We assessed NE-deficient (Dbh -/-) mice and NE-competent (Dbh +/-) controls in MB and NS tasks. We also measured the effects of anti-adrenergic drugs on NS and MB in control mice and the effects of pharmacological restoration of central NE in Dbh -/- mice. Finally, we compared c-fos induction in the locus coeruleus (LC) and ACC of Dbh -/- and control mice following both tasks.

RESULTS

Dbh -/- mice virtually lacked MB and NS behaviors seen in control mice but did not differ in the elevated zero maze (EZM) model of general anxiety-like behavior. Pharmacological restoration of central NE synthesis in Dbh -/- mice completely rescued NS behavior, while NS and MB were suppressed in control mice by anti-adrenergic drugs. Expression of c-fos in the ACC was attenuated in Dbh -/- mice after MB and NS.

CONCLUSION

These findings support a role for NE transmission to the ACC in the expression of stress-induced compulsive behaviors and suggest further evaluation of anti-adrenergic drugs for OCD is warranted.

[Interaction of insomnia in old age and associated diseases : Cognitive, behavioral and neurobiological aspects]

The prevalence of insomnia is particularly high in old age. Sleep disturbances and impaired daytime functioning reflected in mood swings and concentration difficulties are often accompanied by other mental disorders such as depression. The objective of this article is to shed light on the role of insomnia in the context of frequent comorbidities in middle and old age. The focus is on the identification of linkage points between insomnia and associated diseases on a neurobiological level; however, possible distinguishing features are also named and deliberations on cognitive behavioral aspects and integrative theories, such as the hyperarousal theory are discussed. In order to provide an outlook for future research opportunities, the UK Biobank is presented as a promising resource of long-term data. Finally, the contents of the preceding deliberations are critically reflected and practical implications for the treatment of older patients with insomnia are derived.

Functional Connectivity of the Striatum as a Neural Correlate of Symptom Severity in Patient with Obsessive-Compulsive Disorder

OBJECTIVE

It is well established that the cortico-striato-thalamo-cortical (CSTC) circuit is implicated in the pathophysiology of obsessive- compulsive disorder (OCD). However, reports on corticostriatal functional connectivity (FC) in OCD have been inconsistent due to the structural and functional heterogeneity of the striatum. Therefore, in the present study, we investigated corticostriatal FC using a fine 12-seed striatal parcellation to overcome this heterogeneity and discover the neural correlates of symptoms in OCD patients.

METHODS

We recruited 23 OCD patients and 23 healthy controls (HCs). Whole-brain FC based on striatal seeds was examined using resting-state functional magnetic resonance imaging data and compared across OCD patients and HCs. We conducted correlation analysis between FCs of striatal subregions with significant group differences and symptom severity scores on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Hamilton Rating Scale for Depression, and Hamilton Rating Scale for Anxiety (HAM-A).

RESULTS

Compared to HCs, patients demonstrated increased FC of the dorsal caudal putamen and ventral rostral putamen (VRP) with several cortical regions, such as the intracalcarine cortex, inferior frontal gyrus, supramarginal/angular gyrus (SMG/AG), and postcentral gyrus (PCG). Furthermore, FC between the VRP and SMG/AG and between the VRP and PCG was negatively correlated with scores on the Y-BOCS compulsive subscale and the HAM-A, respectively.

CONCLUSION

These findings suggest that striatal subregions have strengthened FC with extensive cortical regions, which may reflect neural correlates of compulsive and anxious symptoms in OCD patients. These results contribute to an improved understanding of OCD pathophysiology by complementing the current evidence regarding striatal FC.

Striatum-Mediated Deficits in Stimulus-Response Learning and Decision-Making in OCD

Obsessive compulsive disorder (OCD) is a prevalent psychiatric disorder characterized by obsessions and compulsions. Studies investigating symptomatology and cognitive deficits in OCD frequently implicate the striatum. The aim of this study was to explore striatum-mediated cognitive deficits in patients with OCD as they complete a stimulus-response learning task previously shown to differentially rely on the dorsal (DS) and ventral striatum (VS). We hypothesized that patients with OCD will show both impaired decision-making and learning, coupled with reduced task-relevant activity in DS and VS, respectively, compared to healthy controls. We found that patients with OCD (n = 14) exhibited decision-making deficits and learned associations slower compared to healthy age-matched controls (n = 16). Along with these behavioral deficits, OCD patients had reduced task-relevant activity in DS and VS, compared to controls. This study reveals that responses in DS and VS are altered in OCD, and sheds light on the cognitive deficits and symptoms experienced by patients with OCD.

The Bed Nucleus of the Stria Terminalis, Homeostatic Satiety, and Compulsions: What Can We Learn From Polydipsia?

A compulsive phenotype characterizes several neuropsychiatric illnesses - including but not limited to - schizophrenia and obsessive compulsive disorder. Because of its perceived etiological heterogeneity, it is challenging to disentangle the specific neurophysiology that precipitates compulsive behaving. Using polydipsia (or non-regulatory water drinking), we describe candidate neural substrates of compulsivity. We further postulate that aberrant neuroplasticity within cortically projecting structures [i.e., the bed nucleus of the stria terminalis (BNST)] and circuits that encode homeostatic emotions (thirst, hunger, satiety, etc.) underlie compulsive drinking. By transducing an inaccurate signal that fails to represent true homeostatic state, cortical structures cannot select appropriate and adaptive actions. Additionally, augmented dopamine (DA) reactivity in striatal projections to and from the frontal cortex contribute to aberrant homeostatic signal propagation that ultimately biases cortex-dependent behavioral selection. Responding becomes rigid and corresponds with both erroneous, inflexible encoding in both bottom-up structures and in top-down pathways. How aberrant neuroplasticity in circuits that encode homeostatic emotion result in the genesis and maintenance of compulsive behaviors needs further investigation.

Volumetric MRI study of orbito-frontal cortex and thalamus in obsessive-compulsive personality disorder

OBJECTIVES

Obsessive compulsive personality disorder (OCPD) is currently thought to bear a close relationship with obsessive-compulsive disorder (OCD), and other compulsive disorders such as eating disorder and autistic spectrum disorder, as well as with the personality disorders, focusing on some important dimensions like phenomenology, heritability, environmental risk factors, comorbidity, course of illness, neurocognitive endophenotypes, and treatment response. In the present study, when we have taken into consideration the knowledge aforementioned, we aimed to examine OFC and thalamus volumes in patients with OCPD.

METHODS

We comparatively measured orbito-frontal cortex (OFC) and thalamus volumes of patients with OCPD and healthy control subjects.

RESULTS

Patients with OCPD had considerably smaller left and right OFC volumes compared to those of healthy control subjects. We also found that thalamus volumes of patients were statistically significantly greater than those of healthy comparisons for both sides of region of interest.

CONCLUSIONS

We consider that volumetric alterations determined in the present study may be involved in the pathophysiology of the OCPD, considering that OCPD might be related to OCD spectrum disorders neuroanatomically.

The Shared and Distinct White Matter Networks Between Drug-Naive Patients With Obsessive-Compulsive Disorder and Schizophrenia

Background: Obsessive-compulsive disorder (OCD) and schizophrenia (SZ) as two severe mental disorders share many clinical symptoms, and have a tight association on the psychopathological level. However, the neurobiological substrates between these two diseases remain unclear. To the best of our knowledge, no study has directly compared OCD with SZ from the perspective of white matter (WM) networks. Methods: Graph theory and network-based statistic methods were applied to diffusion MRI to investigate and compare the WM topological characteristics among 29 drug-naive OCDs, 29 drug-naive SZs, and 65 demographically-matched healthy controls (NC). Results: Compared to NCs, OCDs showed the alterations of nodal efficiency and strength in orbitofrontal (OFG) and middle frontal gyrus (MFG), while SZs exhibited widely-distributed abnormalities involving the OFG, MFG, fusiform gyrus, heschl gyrus, calcarine, lingual gyrus, putamen, and thalamus, and most of these regions also showed a significant difference from OCDs. Moreover, SZs had significantly fewer connections in striatum and visual/auditory cortices than OCDs. The right putamen consistently showed significant differences between both disorders on nodal characteristics and structural connectivity. Conclusions: SZ and OCD present different level of anatomical impairment and some distinct topological patterns, and the former has more serious and more widespread disruptions. The significant differences between both disorders are observed in many regions involving the frontal, temporal, occipital, and subcortical regions. Particularly, putamen may serve as a potential imaging marker to distinguish these two disorders and may be the key difference in their pathological changes.

Variation in fourteen brain structure volumes in schizophrenia: A comprehensive meta-analysis of 246 studies

Despite hundreds of structural MRI studies documenting smaller brain volumes on average in schizophrenia compared to controls, little attention has been paid to group differences in the variability of brain volumes. Examination of variability may help interpret mean group differences in brain volumes and aid in better understanding the heterogeneity of schizophrenia. Variability in 246 MRI studies was meta-analyzed for 13 structures that have shown medium to large mean effect sizes (Cohen's d≥0.4): intracranial volume, total brain volume, lateral ventricles, third ventricle, total gray matter, frontal gray matter, prefrontal gray matter, temporal gray matter, superior temporal gyrus gray matter, planum temporale, hippocampus, fusiform gyrus, insula; and a control structure, caudate nucleus. No significant differences in variability in cortical/subcortical volumes were detected in schizophrenia relative to controls. In contrast, increased variability was found in schizophrenia compared to controls for intracranial and especially lateral and third ventricle volumes. These findings highlight the need for more attention to ventricles and detailed analyses of brain volume distributions to better elucidate the pathophysiology of schizophrenia.

Age and gender interactions in white matter of schizophrenia and obsessive compulsive disorder compared to non-psychiatric controls: commonalities across disorders

Schizophrenia (SCZ) and obsessive-compulsive disorder (OCD) are psychiatric disorders with abnormalities in white matter structure. These disorders share high comorbidity and family history of OCD is a risk factor for SCZ which suggests some shared neurobiology. White matter was examined using diffusion tensor imaging in relativity large samples of SCZ (N = 48), OCD (N = 38) and non-psychiatric controls (N = 45). Fractional anisotropy (FA) was calculated and tract based spatial statistics were used to compare groups. In a whole brain analysis, SCZ and OCD both showed small FA reductions relative to controls in the corpus callosum. Both SCZ and OCD showed accelerated reductions in FA with age; specifically in the left superior longitudinal fasciculus in OCD, while the SCZ group demonstrated a more widespread pattern of FA reduction. Patient groups did not differ from each other in total FA or age effects in any regions. A general linear model using 13 a-priori regions of interest showed marginal group, group*gender, and group*age interactions. When OCD and SCZ groups were analyzed together, these marginal effects became significant (p < 0.05), suggesting commonalities exist between these patient groups. Overall, our results demonstrate a similar pattern of accelerated white matter decline with age and greater white matter deficit in females in OCD and SCZ, with overlap in the spatial pattern of deficits. There was no evidence for statistical differences in overall white matter between OCD and SCZ. Taken together, the results support the notion of shared neurobiology in SCZ and OCD.

Orbito-frontal cortex and thalamus volumes in the patients with obsessive-compulsive disorder before and after cognitive behavioral therapy

Background The effect of a variety of treatment modalities including psychopharmacological and cognitive behavioral therapy on the brain volumes and neurochemicals have not been investigated enough in the patients with obsessive-compulsive disorder. Therefore, in the present study, we aimed to investigate the effect of cognitive behavioral therapy on the volumes of the orbito-frontal cortex and thalamus regions which seem to be abnormal in the patients with obsessive-compulsive disorder. We hypothesized that there would be change in the volumes of the orbito-frontal cortex and thalamus. Methods Twelve patients with obsessive-compulsive disorder and same number of healthy controls were included into the study. At the beginning of the study, the volumes of the orbito-frontal cortex and thalamus were compared by using magnetic resonance imaging. In addition, volumes of these regions were measured before and after the cognitive behavioral therapy treatment in the patient group. Results The patients with obsessive-compulsive disorder had greater left and right thalamus volumes and smaller left and right orbito-frontal cortex volumes compared to those of healthy control subjects at the beginning of the study. When we compared baseline volumes of the patients with posttreatment ones, we detected that thalamus volumes significantly decreased throughout the period for both sides and that the orbito-frontal cortex volumes significantly increased throughout the period for only left side. Conclusions In summary, we found that cognitive behavioral therapy might volumetrically affect the key brain regions involved in the neuroanatomy of obsessive-compulsive disorder. However, future studies with larger sample are required.

Amygdala volume mediates the relationship between externalizing symptoms and daily smoking in adolescence: A prospective study

The current study examined amygdala and orbitofrontal cortex (OFC) volumes as mediators of the relationship between externalizing symptoms and daily smoking in adolescence. Externalizing behaviors are among the most robust predictors of adolescent smoking, and there is emerging evidence that volume reductions in the amygdala and OFC are associated with risk for substance misuse as well as aggressive, impulsive, and disinhibited tendencies. Using a prospective longitudinal design, we recruited 109 adolescents who provided data on brain volume and externalizing behaviors at age 12, and on smoking at age 18. Daily smoking at age 18 (n = 27) was predicted by externalizing behaviors (measured by the self-report Child Behavior Checklist, CBCL) as well as smaller right amygdala volumes. Right amygdala volumes mediated the relationship between externalizing symptoms and later smoking. These findings provide important insight into the neurobiological risk factors associated with adolescent smoking, and, more generally, into factors that may be associated with vulnerability to substance use disorders and related psychopathology.

Pituitary gland volumes in patients with obsessive-compulsive disorder before and after cognitive-behavioral therapy

OBJECTIVE

The beneficial effects of psychopharmacological and cognitive behavioral therapy (CBT) on the brain are not well understood. In a previous study, we found smaller pituitary volumes in patients with obsessive-compulsive disorder (OCD). The purpose of this study was to examine the effect of CBT on pituitary gland volume.

METHODS

A total of 81 patients with various anxiety disorders and the same number of healthy controls underwent magnetic resonance imaging, and their pituitary gland volumes were compared at baseline. Pituitary gland volumes were also measured before and after CBT in the patient group.

RESULTS

OCD patients had smaller pituitary gland volumes at baseline than healthy controls (0.54±0.29 cm3 for OCD patients vs. 0.82±0.30 cm3 for healthy controls; p < 0.001). We found no significant changes in OCD patient pituitary gland volume after the 16-week treatment period, with mean pre- and post-treatment values of 0.54±0.29 cm3 and 0.56±0.32 cm3, respectively (p > 0.05).

CONCLUSION

Our results indicate an absence of post-CBT volumetric changes in the pituitary gland of OCD patients.

Orbito-frontal cortex and thalamus volumes in obsessive-compulsive disorder before and after pharmacotherapy

In the present study, we focused on the key brain regions, OFC and thalamus, to investigate the roles of antiobsessional agents on volume changes of these brain regions after 12 weeks of anti-obsessional treatment in patients with obsessive-compulsive disorder (OCD). Fourteen patients with OCD and the same number of healthy controls were included in the study. At baseline, the volumes of the OFC and thalamus were compared by using magnetic resonance imaging (MRI) between groups. The volumes of OFC and thalamus were evaluated before and after the anti-obsessional drug treatment solely in the patient group. Our study revealed that thalamus volumes were reduced statistically significantly throughout the treatment period. However, we found that OFC volumes did not change statistically significantly throughout the treatment period. In summary, our study found that anti-obsessional drug treatment had an effect on thalamus volumes throughout the treatment period for both sides but not on OFC volumes. However, future studies with larger sample are required.

Regional Volumetric Differences Based on Structural MRI in Children With Two Subtypes of ADHD and Controls

OBJECTIVE

The purpose of this study was to compare groups of children with two subtypes of ADHD and controls on selected regions using volumetric magnetic resonance imaging (MRI) measures. Children with ADHD were expected to have smaller volumes of the anterior cingulate cortex (ACC) and caudate. Parent behavioral rating measures of hyperactivity were predicted to relate to the volume of the caudate and attention with the ACC.

METHOD

There were a total of 74 children in the final sample (27 controls, 25 ADHD:Combined type [ADHD:C], 22 ADHD:Inattentive type [ADHD:I]).

RESULTS

Findings indicated that the ADHD:C group had bilaterally smaller volumes of the caudate and ACC compared with the other two groups. In addition, parent ratings of attention and hyperactivity significantly predicted the right volume of the ACC, whereas hyperactivity ratings predicted the volume of the right caudate. Analysis of the ADHD groups without the control confirmed these findings.

CONCLUSION

These findings indicate that different structures are related to the ADHD subtypes and suggest that they may be different phenotypes.

Comparative Multimodal Meta-analysis of Structural and Functional Brain Abnormalities in Autism Spectrum Disorder and Obsessive-Compulsive Disorder

BACKGROUND

Autism spectrum disorder (ASD) and obsessive-compulsive disorder (OCD) share inhibitory control deficits possibly underlying poor control over stereotyped and repetitive and compulsive behaviors, respectively. However, it is unclear whether these symptom profiles are mediated by common or distinct neural profiles. This comparative multimodal meta-analysis assessed shared and disorder-specific neuroanatomy and neurofunction of inhibitory functions.

METHODS

A comparative meta-analysis of 62 voxel-based morphometry and 26 functional magnetic resonance imaging (fMRI) studies of inhibitory control was conducted comparing gray matter volume and activation abnormalities between patients with ASD (structural MRI: 911; fMRI: 188) and OCD (structural MRI: 928; fMRI: 247) and control subjects. Multimodal meta-analysis compared groups across voxel-based morphometry and fMRI.

RESULTS

Both disorders shared reduced function and structure in the rostral and dorsomedial prefrontal cortex including the anterior cingulate. OCD patients had a disorder-specific increase in structure and function of left basal ganglia (BG) and insula relative to control subjects and ASD patients, who had reduced right BG and insula volumes versus OCD patients. In fMRI, ASD patients showed disorder-specific reduced left dorsolateral-prefrontal activation and reduced posterior cingulate deactivation, whereas OCD patients showed temporoparietal underactivation.

CONCLUSIONS

The multimodal comparative meta-analysis shows shared and disorder-specific abnormalities. Whereas the rostrodorsomedial prefrontal cortex was smaller in structure and function in both disorders, this was concomitant with increased structure and function in BG and insula in OCD patients, but a reduction in ASD patients, presumably reflecting a disorder-specific frontostriatoinsular dysregulation in OCD in the form of poor frontal control over overactive BG, and a frontostriatoinsular maldevelopment in ASD with reduced structure and function in this network. Disorder-differential mechanisms appear to drive overlapping phenotypes of inhibitory control abnormalities in patients with ASD and OCD.

Meta-analytic investigations of common and distinct grey matter alterations in youths and adults with obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a disabling illness with onset generally in childhood. OCD-youths differ from OCD-adults with regard to gender distribution, comorbidity patterns and treatment options. However, little is known about the neural correlate differences underpin those two populations. The current meta-analysis summarizes voxel based morphometry findings to elucidate whether differences of neural correlates exist between these two populations. Both OCD-youths and OCD-adults demonstrated greater striatal volume and smaller prefrontal grey matter volume (GMV). However, smaller GMV in left visual cortex was observed in OCD-youths only, while smaller GMV in anterior cingulate gyrus and greater GMV in cerebellum were demonstrated only in OCD-adults. Meta-regression showed greater GMV in left putamen was most prominent in samples with higher percentages of medicated OCD-adults. Our findings confirmed the most consistent GMV alterations in OCD were in prefrontal-striatal circuitry. Besides, other regions may involve at different developmental stages including deficits of visual cortex in OCD-youths and abnormalities of limbic-cerebellar circuit in OCD-adults. Medication effect may be more pronounced in the striatum, especially the putamen.

Cognitive-Behavioral Therapy for Obsessive-Compulsive Disorder with and without Autism Spectrum Disorder: Gray Matter Differences Associated with Poor Outcome

Cognitive behavioral therapy (CBT) is an effective treatment for obsessive-compulsive disorder (OCD) and is also applicable to patients with both OCD and autism spectrum disorder (ASD). However, previous studies have reported that CBT for patients with both OCD and ASD might be less effective than for patients with OCD alone. In addition, there is no evidence as to why autistic traits might be risk factors. Therefore, we investigated whether comorbidity between ASD and OCD may significantly affect treatment outcome and discovered predictors of CBT outcomes using structural magnetic resonance imaging (MRI) data. A total of 39 patients, who were diagnosed with OCD, were enrolled in this study. Of these, except for 2 dropout cases, 15 patients were diagnosed with ASD, and 22 patients were diagnosed with OCD without ASD. Both groups took CBT for 11-20 sessions. First, to examine the effectiveness of CBT for OCD patients with and without ASD, we compared CBT outcomes between the two groups. Second, to investigate how the structural abnormality profile of the brain at pretreatment influenced CBT outcomes, we performed a structural MRI comparison focusing on the gray matter volume of the whole brain in both patients with only OCD, and those with both OCD and ASD. In order to discover neurostructural predictors of CBT outcomes besides autistic traits, we divided our samples again into two groups of those who did and those who did not remit after CBT, and repeated the analysis taking autistic traits into account. The results showed that OCD patients with ASD responded significantly less well to CBT. The OCD patients with ASD had much less gray matter volume in the left occipital lobe than OCD patients without ASD. The non-remission group had a significantly smaller volume of gray matter in the left dorsolateral prefrontal cortex (DLPFC) compared with the remission group, after having partialed out autistic traits. These results indicate that the abnormalities in DLPFC negatively affect the CBT outcome, regardless of the severity of the autistic traits.

Executive functions in obsessive-compulsive disorder: An activation likelihood estimate meta-analysis of fMRI studies

OBJECTIVES

To identify activation changes assessed in functional magnetic resonance imaging (fMRI) studies of obsessive-compulsive disorder (OCD) through Activation Likelihood Estimate meta-analysis.

METHODS

We included 28 peer-reviewed standard stereotactic space studies assessing adult OCD patients (OCDpts) vs. healthy controls (HCs) with fMRI during executive task performance.

RESULTS

In within-group analyses, HCs showed task-related activations in bilateral inferior frontal gyri, right middle frontal gyrus, right inferior parietal lobule, right claustrum, bilateral cingulate gyri, and left caudate body. OCDpts showed task-related left-sided activations in the superior, medial, and inferior frontal gyri, and thalamus, and bilateral activations in the middle frontal gyri, inferior parietal lobule, and insular cortices. Subtraction analysis showed increased left middle frontal gyrus activation in OCDpts. In between-groups analyses, OCDpts hypoactivated the right caudate body, left putamen, left ACC, and right medial and middle frontal gyri. Right caudate hypoactivation persisted also after applying Family-wise error algorithms.

CONCLUSIONS

This meta-analysis confirms that during executive functioning OCDpts show a functional deficit of the right caudate body, which could represent a major neural functional correlate of their illness.

Increased fractional anisotropy in cerebellum in obsessive-compulsive disorder

BACKGROUND

Previous morphology and diffusion-imaging studies have suggested that structural changes in white matter is an important part of the pathophysiology of obsessive-compulsive disorder (OCD). However, different methodological approaches and the heterogeneity of patient samples question the validity of the findings. Materials and methods In total, 30 patients were matched for age and sex with 30 healthy controls. All participants underwent T1-weighted magnetic resonance imaging, diffusion tensor imaging and T2 fluid-attenuated inversion recovery. Voxel-based morphometry and tract-based spatial statistics were used to compare white matter volumes and diffusion tensor imaging between groups. These data were analysed correcting for the effects of multiple comparisons, age, sex, severity and duration of illness as nuisance covariates. White matter hyperintensities were manually identified.

RESULTS

Increase in fractional anisotropy in cerebellum was the most prominent result. A decrease in fractional anisotrophy in patients comparable with previous studies was located in forceps minor. There were no differences in the white matter morphology or in the white matter hyperintensities between patients and healthy controls.

CONCLUSION

Decrease in fractional anisotrophy in forceps minor and increase in cerebellum were found, and they were not due to neither white matter hyperintensities nor morphology of the white matter. Cerebellar hyperconnectivity could be an important part of OCD pathophysiology.

Role of the dorsal anterior cingulate cortex in obsessive-compulsive disorder: converging evidence from cognitive neuroscience and psychiatric neurosurgery

OBJECTIVE Advances in understanding the neurobiological basis of psychiatric disorders will improve the ability to refine neuromodulatory procedures for treatment-refractory patients. One of the core dysfunctions in obsessive-compulsive disorder (OCD) is a deficit in cognitive control, especially involving the dorsal anterior cingulate cortex (dACC). The authors' aim was to derive a neurobiological understanding of the successful treatment of refractory OCD with psychiatric neurosurgical procedures targeting the dACC. METHODS First, the authors systematically conducted a review of the literature on the role of the dACC in OCD by using the search terms "obsessive compulsive disorder" and "anterior cingulate." The neuroscience literature on cognitive control mechanisms in the dACC was then combined with the literature on psychiatric neurosurgical procedures targeting the dACC for the treatment of refractory OCD. RESULTS The authors reviewed 89 studies covering topics that included structural and functional neuroimaging and electrophysiology. The majority of resting-state functional neuroimaging studies demonstrated dACC hyperactivity in patients with OCD relative to that in controls, while task-based studies were more variable. Electrophysiological studies showed altered dACC-related biomarkers of cognitive control, such as error-related negativity in OCD patients. These studies were combined with the cognitive control neurophysiology literature, including the recently elaborated expected value of control theory of dACC function. The authors suggest that a central feature of OCD pathophysiology involves the generation of mis-specified cognitive control signals by the dACC, and they elaborate on this theory and provide suggestions for further study. CONCLUSIONS Although abnormalities in brain structure and function in OCD are distributed across a wide network, the dACC plays a central role. The authors propose a theory of cognitive control dysfunction in OCD that attempts to explain the therapeutic efficacy of dACC neuromodulation. This theoretical framework should help to guide further research into targeted treatments of OCD and other disorders of cognitive control.

Mild White Matter Changes in Un-medicated Obsessive-Compulsive Disorder Patients and Their Unaffected Siblings

Objective: Obsessive-compulsive disorder (OCD) is a common neuropsychiatric disorder with moderate genetic influences and white matter abnormalities in frontal-striatal and limbic regions. Inconsistencies in reported white matter results from diffusion tensor imaging (DTI) studies can be explained, at least partly, by medication use and between-group differences in disease profile and stage. We used a family design aiming to establish whether white matter abnormalities, if present in un-medicated OCD patients, also exist in their unaffected siblings.

Method: Forty-four OCD patients, un-medicated for at least the past 4 weeks, 15 of their unaffected siblings, and 37 healthy controls (HC) underwent DTI using a 3-Tesla MRI-scanner. Data analysis was done using tract-based spatial statistics (TBSS). Fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) values were compared within seven skeletonised regions of interest (ROIs), i.e., corpus callosum, bilateral cingulum bundle, bilateral inferior longitudinal fasciculus/frontal-occipital fasciculus (ILF/FOF) and bilateral superior longitudinal fasciculus (SLF).

Results: Un-medicated OCD patients, compared with HC, had significantly lower FA in the left cingulum bundle. FA was trend-significantly lower in all other ROIs, except for the corpus callosum. Significant three-group differences in FA (and in RD at trend-significant level) were observed in the left cingulum bundle, with the unaffected siblings representing an intermediate group between OCD patients and HC.

Conclusions: OCD patients showed lower FA in the left cingulum bundle, partly driven by trend-significantly higher values in RD. Since the unaffected siblings were found to be an intermediate group between OCD patients and HC, this white matter alteration may be considered an endophenotype for OCD.

Alterations of Gray and White Matter Networks in Patients with Obsessive-Compulsive Disorder: A Multimodal Fusion Analysis of Structural MRI and DTI Using mCCA+jICA

Many of previous neuroimaging studies on neuronal structures in patients with obsessive-compulsive disorder (OCD) used univariate statistical tests on unimodal imaging measurements. Although the univariate methods revealed important aberrance of local morphometry in OCD patients, the covariance structure of the anatomical alterations remains unclear. Motivated by recent developments of multivariate techniques in the neuroimaging field, we applied a fusion method called "mCCA+jICA" on multimodal structural data of T1-weighted magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) of 30 unmedicated patients with OCD and 34 healthy controls. Amongst six highly correlated multimodal networks (p < 0.0001), we found significant alterations of the interrelated gray and white matter networks over occipital and parietal cortices, frontal interhemispheric connections and cerebella (False Discovery Rate q ≤ 0.05). In addition, we found white matter networks around basal ganglia that correlated with a subdimension of OC symptoms, namely 'harm/checking' (q ≤ 0.05). The present study not only agrees with the previous unimodal findings of OCD, but also quantifies the association of the altered networks across imaging modalities.

1HMRS results of hippocampus in the patients with obsessive-compulsive disorder before and after cognitive behavioral therapy

OBJECTIVE

In the present study, we examined the effects of cognitive behavioral therapy (CBT) on the hippocampal neurochemistry in patients with obsessive-compulsive disorder (OCD).

METHODS

Twelve patients with OCD and same number of healthy controls were included into the study. Neurochemical variables of the hippocampus were measured before and after the CBT treatment in the patient group.

RESULTS

At baseline, the patients with OCD had significantly lower ratio of N-acetyl-l-aspartate/choline (NAA/CHO) compared with that of healthy control subjects. When comparing pre-treatment results of the patient group with those of post-treatment ones using paired t-test, we found that NAA/CHO ratio increased from 2.47 ± 0.64 to 3.66 ± 0.88, with a statisical significance.

CONCLUSIONS

The findings may implicate that CBT increases the level of NAA which is a marker of neuronal integrity.

Association between serotonin transporter genotype, brain structure and adolescent-onset major depressive disorder: a longitudinal prospective study

The extent to which brain structural abnormalities might serve as neurobiological endophenotypes that mediate the link between the variation in the promoter of the serotonin transporter gene (5-HTTLPR) and depression is currently unknown. We therefore investigated whether variation in hippocampus, amygdala, orbitofrontal cortex (OFC) and anterior cingulate cortex volumes at age 12 years mediated a putative association between 5-HTTLPR genotype and first onset of major depressive disorder (MDD) between age 13-19 years, in a longitudinal study of 174 adolescents (48% males). Increasing copies of S-alleles were found to predict smaller left hippocampal volume, which in turn was associated with increased risk of experiencing a first onset of MDD. Increasing copies of S-alleles also predicted both smaller left and right medial OFC volumes, although neither left nor right medial OFC volumes were prospectively associated with a first episode of MDD during adolescence. The findings therefore suggest that structural abnormalities in the left hippocampus may be present prior to the onset of depression during adolescence and may be partly responsible for an indirect association between 5-HTTLPR genotype and depressive illness. 5-HTTLPR genotype may also impact upon other regions of the brain, such as the OFC, but structural differences in these regions in early adolescence may not necessarily alter the risk for onset of depression during later adolescence.

Volumetric MRI differences in treatment naïve and chronically treated adolescents with ADHD-combined type

OBJECTIVE

The purpose of this study was to determine whether there are differences in the volume of specific brain regions using magnetic resonance imaging (MRI) between children and adolescents with ADHD and controls and whether such differences are related to the participants' history of stimulant treatment.

METHOD

A total of 16 healthy controls, 16 children, and adolescents with ADHD-combined (ADHD-C) type with a history of stimulant treatment, and 13 children and adolescents with ADHD-C type treatment naïve participated.

RESULTS

Total frontal, prefrontal, and caudate volumes were larger for children and adolescents with ADHD compared with controls with no differences based on medication history with larger right gray and white matter prefrontal volumes in the ADHD groups. A medication difference was found with the right anterior cingulate cortex smaller in children and adolescents without a treatment history.

CONCLUSION

These findings suggest that aberrant prefrontal and caudate volumes in ADHD-C may compromise functioning of the frontostriatal circuitry.

Multimodal voxel-based meta-analysis of white matter abnormalities in obsessive-compulsive disorder

White matter (WM) abnormalities have long been suspected in obsessive-compulsive disorder (OCD) but the available evidence has been inconsistent. We conducted the first multimodal meta-analysis of WM volume (WMV) and fractional anisotropy (FA) studies in OCD. All voxel-wise studies comparing WMV or FA between patients with OCD and healthy controls in the PubMed, ScienceDirect, Google Scholar, Web of Knowledge and Scopus databases were retrieved. Manual searches were also conducted and authors were contacted soliciting additional data. Thirty-four data sets were identified, of which 22 met inclusion criteria (five of them unpublished; comprising 537 adult and pediatric patients with OCD and 575 matched healthy controls). Whenever possible, raw statistical parametric maps were also obtained from the authors. Peak and raw WMV and FA data were combined using novel multimodal meta-analytic methods implemented in effect-size signed differential mapping. Patients with OCD showed widespread WM abnormalities, but findings were particularly robust in the anterior midline tracts (crossing between anterior parts of cingulum bundle and body of corpus callosum), which showed both increased WMV and decreased FA, possibly suggesting an increase of fiber crossing in these regions. This finding was also observed when the analysis was limited to adult participants, and especially pronounced in samples with a higher proportion of medicated patients. Therefore, patients with OCD may have widespread WM abnormalities, particularly evident in anterior midline tracts, although these changes might be, at least in part, attributable to the effects of therapeutic drugs.

Volumetric differences in the anterior cingulate cortex prospectively predict alcohol-related problems in adolescence

RATIONALE

Individual differences in brain structure and function are suggested to exist prior to the onset of alcohol abuse. Cross-sectional studies have demonstrated abnormalities in brain regions underlying affective processes that may form a pathway to the emergence of later alcohol abuse and dependence in vulnerable individuals. However, no prospective studies have examined whether these abnormalities predict later problems with alcohol.

OBJECTIVE

This study aims to examine whether individual differences in affect and brain volume prospectively predict alcohol-related problems in adolescence.

METHOD

Adolescent drinkers (n = 98) were recruited from an ongoing prospective, longitudinal study examining adolescent emotional development. At age 12, participants underwent structural magnetic resonance imaging to obtain volumetric data on the amygdala, hippocampus, orbitofrontal cortex, and anterior cingulate cortex (ACC), and completed a self-report measure of affective temperament. At age 16, participants completed a questionnaire measuring alcohol use, with 39 % reporting alcohol-related problems in the past year.

RESULTS

Pre-existing differences in the left ACC predicted problem drinking. Alcohol-related problems were associated with higher levels of temperamental negative affectivity; however, these were not correlated with anterior cingulate volumes.

CONCLUSIONS

These findings indicate that individual differences in the structural morphology of the anterior cingulate, a region implicated in affective processes, self-control, and drug addiction, predict later alcohol-related problems. Although this finding remained significant after controlling for other substance use and psychopathology, future research is required to test its specificity for alcohol use disorders.

Brain microstructural changes and cognitive correlates in patients with pure obsessive compulsive disorder

OBJECT

The aim of this study was to investigate macrostructural and microstructural brain changes in patients with pure obsessive compulsive disorder (OCD) and to examine the relationship between brain structure and neuropsychological deficits.

METHOD

20 patients with OCD underwent a comprehensive neuropsychological battery. A combined voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) analysis was used to capture gray matter (GM) and white matter changes in OCD patients as compared to pair-matched healthy volunteers. Multiple regression designs explored the relationship between cognition and neuroimaging parameters.

RESULTS

OCD patients had increased mean diffusivity (MD) in GM nodes of the orbitofronto-striatal loop (left dorsal anterior cingulate [Z = 3.67, P < 0.001] left insula [Z = 3.35 P < 0.001] left thalamus [Z = 3.59, P < 0.001] left parahippocampal gyrus [Z = 3.77 P < 0.001]) and in lateral frontal and posterior associative cortices (right frontal operculum [Z = 3.42 P < 0.001], right temporal lobe [Z = 3.79 P < 0.001] left parietal lobe [Z = 3.91 P < 0.001]). Decreased fractional anisotropy (FA) was detected in intrahemispheric (left superior longitudinal fasciculus [Z = 4.07 P < 0.001]) and interhemispheric (body of corpus callosum [CC, Z = 4.42 P < 0.001]) bundles. Concurrently, the semantic fluency score, a measure of executive control processes, significantly predicted OCD diagnosis (Odds Ratio = 1.37; 95% Confidence Intervals = 1.09-1.73; P = 0.0058), while variation in performance was correlated with increased MD in left temporal (Z = 4.25 P < 0.001) and bilateral parietal regions (left Z = 3.94, right Z = 4.19 P < 0.001), and decreased FA in the right posterior corona radiata (Z = 4.07 P < 0.001) and the left corticospinal tract (Z = 3.95 P < 0.001).

CONCLUSIONS

The reported deficit in executive processes and the underlying microstructural alterations may qualify as behavioral and biological markers of OCD.

Sex differences in structural brain asymmetry predict overt aggression in early adolescents

The devastating social, emotional and economic consequences of human aggression are laid bare nightly on newscasts around the world. Aggression is principally mediated by neural circuitry comprising multiple areas of the prefrontal cortex and limbic system, including the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), amygdala and hippocampus. A striking characteristic of these regions is their structural asymmetry about the midline (i.e. left vs right hemisphere). Variations in these asymmetries have been linked to clinical disorders characterized by aggression and the rate of aggressive behavior in psychiatric patients. Here, we show for the first time that structural asymmetries in prefrontal cortical areas are also linked to aggression in a normal population of early adolescents. Our findings indicate a relationship between parent reports of aggressive behavior in adolescents and structural asymmetries in the limbic and paralimbic ACC and OFC, and moreover, that this relationship varies by sex. Furthermore, while there was no relationship between aggression and structural asymmetries in the amygdala or hippocampus, hippocampal volumes did predict aggression in females. Taken together, the results suggest that structural asymmetries in the prefrontal cortex may influence human aggression, and that the anatomical basis of aggression varies substantially by sex.

Volumetric structural magnetic resonance imaging findings in pediatric posttraumatic stress disorder and obsessive compulsive disorder: a systematic review

OBJECTIVES

Structural magnetic resonance imaging (sMRI) studies of anxiety disorders in children and adolescents are limited. Posttraumatic stress disorder (PTSD) and obsessive compulsive disorder (OCD) have been best studied in this regard. We systematically reviewed structural neuroimaging findings in pediatric PTSD and OCD.

METHODS

The literature was reviewed for all sMRI studies examining volumetric parameters using PubMed, ScienceDirect, and PsychInfo databases, with no limit on the time frame of publication. Nine studies in pediatric PTSD and six in OCD were suitable for inclusion.

RESULTS

Volumetric findings were inconsistent in both disorders. In PTSD, findings suggest increased as well as decreased volumes of the prefrontal cortex (PFC) and corpus callosum; whilst in OCD studies indicate volumetric increase of the putamen, with inconsistent findings for the anterior cingulate cortex (ACC) and frontal regions.

CONCLUSIONS

Methodological differences may account for some of this inconsistency and additional volume-based studies in pediatric anxiety disorders using more uniform approaches are needed.

Brain structural abnormalities in obsessive-compulsive disorder: converging evidence from white matter and grey matter

INTRODUCTION

Specific cortico-striato-thalamic circuits are hypothesised to underlie the aetiology of obsessive-compulsive disorder (OCD). However, findings from neuroimaging studies have been inconsistent. In the current study, we attempted to provide a complete overview of structural alterations in OCD by conducting signed differential mapping (SDM) meta-analysis on grey matter and white matter studies of patients with OCD based on voxel-based morphometry (VBM) studies and diffusion tensor imaging (DTI) studies.

METHODS

Fifteen VBM and seven DTI case-control studies were included in this meta-analysis. SDM meta-analyses were performed to assess grey matter volume and white matter integrity changes in OCD patients and healthy controls.

RESULTS

We found that OCD patients had smaller grey matter volume than health controls in the frontal eye fields, medial frontal gyrus and anterior cingulate cortex. However, we showed that there was an increase in the grey matter volume in the lenticular nucleus, caudate nucleus and a small region in the right superior parietal lobule. OCD patients also had a lower fractional anisotropy (FA) in the cingulum bundles, inferior fronto-occipital fasciculus, and superior longitudinal fasciculus, while increased FA in the left uncinate fasciculus.

CONCLUSIONS

The current findings confirm the structural abnormalities of cortico-striato-thalamic circuits in OCD.