Food addiction in anorexia nervosa: Implications for the understanding of crossover diagnosis.

OBJECTIVE: Food addiction (FA) construct was introduced to reflect abnormal eating patterns that resemble behavioural ones found in substance use disorders. FA has been barely explored in anorexia nervosa (AN). This study evaluated FA occurrence and associated factors in a sample of patients with AN, distinguishing between restrictive and binge-purging subtypes and focussing on the influence of FA in the crossover diagnosis between them. METHOD: A sample of 116 patients with AN admitted for treatment seeking at an Bellvitge Hospital Eating Disorders Unit were included (72 restrictive [AN-R]; 44 binge-purge AN [AN-BP]), and eating-related, personality and psychopathological variables were assessed. Most participants were women (92.2%), mean age 27.1 years old (SD = 10.5). RESULTS: FA was more prevalent in patients with AN-BP compared to the AN-R group (75.0% and 54.2%, respectively). The patients with AN-R FA+, presented more similar ED symptomatology, general psychopathology and personality traits, with the AN-BP patients, than with the AN-R FA-. CONCLUSIONS: Patients with AN-R FA+, exhibit more similarities with the AN-BP subgroup than with the AN-R FA-. Thus, it is possible to hypothesise that the presence of FA might be an indicator of the possible crossover from AN-R to AN-BP.

Taking Care of Those Who Care: Attending Psychological Needs of Health Workers in a Hospital in Madrid (Spain) During the COVID-19 Pandemic.

PURPOSE OF REVIEW: We aim to review evidence of the psychological impact of the COVID-19 pandemic on healthcare professionals and the effects of the psychological crisis interventions and measures implemented to manage stress. RECENT FINDINGS: Mental health problems are frequently encountered in health professionals during emergencies and often prevail over the following years. Results show health professionals exhibited symptoms of depression, anxiety, emotional distress, burnout, post-traumatic stress and poor sleep quality. In response to acute responses to stress, it is crucial to provide psychoeducation, mindfulness and coping resources. These interventions can improve resilience and self-efficacy of professionals, as well as help to prevent anxiety, depression and quality of sleep. The need for intervention programmes targeting the mental health of vulnerable populations has been widely acknowledged. We described a psychological support plan designed and implemented with the aim of providing mental health care for health professionals. Such programmes should be easily accessible to professionals, preferably in their own work environments.

Brain structural covariance networks in obsessive-compulsive disorder: a graph analysis from the ENIGMA Consortium.

Brain structural covariance networks reflect covariation in morphology of different brain areas and are thought to reflect common trajectories in brain development and maturation. Large-scale investigation of structural covariance networks in obsessive-compulsive disorder (OCD) may provide clues to the pathophysiology of this neurodevelopmental disorder. Using T1-weighted MRI scans acquired from 1616 individuals with OCD and 1463 healthy controls across 37 datasets participating in the ENIGMA-OCD Working Group, we calculated intra-individual brain structural covariance networks (using the bilaterally-averaged values of 33 cortical surface areas, 33 cortical thickness values, and six subcortical volumes), in which edge weights were proportional to the similarity between two brain morphological features in terms of deviation from healthy controls (i.e. z-score transformed). Global networks were characterized using measures of network segregation (clustering and modularity), network integration (global efficiency), and their balance (small-worldness), and their community membership was assessed. Hub profiling of regional networks was undertaken using measures of betweenness, closeness, and eigenvector centrality. Individually calculated network measures were integrated across the 37 datasets using a meta-analytical approach. These network measures were summated across the network density range of K = 0.10-0.25 per participant, and were integrated across the 37 datasets using a meta-analytical approach. Compared with healthy controls, at a global level, the structural covariance networks of OCD showed lower clustering (P < 0.0001), lower modularity (P < 0.0001), and lower small-worldness (P = 0.017). Detection of community membership emphasized lower network segregation in OCD compared to healthy controls. At the regional level, there were lower (rank-transformed) centrality values in OCD for volume of caudate nucleus and thalamus, and surface area of paracentral cortex, indicative of altered distribution of brain hubs. Centrality of cingulate and orbito-frontal as well as other brain areas was associated with OCD illness duration, suggesting greater involvement of these brain areas with illness chronicity. In summary, the findings of this study, the largest brain structural covariance study of OCD to date, point to a less segregated organization of structural covariance networks in OCD, and reorganization of brain hubs. The segregation findings suggest a possible signature of altered brain morphometry in OCD, while the hub findings point to OCD-related alterations in trajectories of brain development and maturation, particularly in cingulate and orbitofrontal regions.

The impact of duration of illness on treatment nonresponse and drop-out: Exploring the relevance of enduring eating disorder concept.

OBJECTIVE: There are no generally accepted definitions or markers of treatment nonresponse in eating disorders (EDs). The aim of this paper was to examine how the duration of illness and other potential prognostic markers impacted on nonresponse and drop-out from treatment across different EDs subtypes. METHODS: A total sample of 1199 consecutively treated patients with EDs, according to Diagnostic and Statistical Manual of Mental Disorders, fifth edition criteria, participated in this study. Kaplan-Meier curves were calculated for each ED diagnosis in which the probability of recovery was plotted against the duration of illness. RESULTS: Full remission was more likely for people with binge eating disorder (BED; 47.4%) and anorexia nervosa (AN; 43.9%) compared to bulimia nervosa (BN; 25.2%) and other specified feeding and EDs (OSFED; 23.2%). The cut-off points for the duration of the illness related with high likelihoods of poor response was 6-8 years among OSFED, 12-14 years among AN and BN and 20-21 years among BED. Other variables predicting nonresponse included dysfunctional personality traits. CONCLUSIONS: Nonresponse to treatment is associated with duration of illness which is in turn associated with poor response to previous treatment. However, there was no evidence for staging the illness using specific duration of illness criteria. Nevertheless, the shorter temporal trajectory for OSFED suggests that early interventions may be of importance for this group.

Increased brain fractional perfusion in obesity using intravoxel incoherent motion (IVIM) MRI metrics.

OBJECTIVE: This research seeks to shed light on the associations between brain perfusion, cognitive function, and mental health in individuals with and without obesity. METHODS: In this study, we employed the noninvasive intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) technique to examine brain fractional perfusion (FP) in two groups: individuals with obesity (N = 72) and healthy controls (N = 66). Additionally, we investigated potential associations between FP, cognitive function, and depressive symptoms in the participants with and without obesity. Finally, artificial intelligence algorithms (Boruta analysis) were also used. RESULTS: Participants with obesity exhibited increased FP within dopaminergic brain circuits, particularly involving prefrontal cortex areas, anterior and posterior sections of the cingulate cortex, the right striatum, and the midbrain. Additionally, these individuals demonstrated lower working memory and higher depressive symptoms compared to the control group. Notably, higher FP in the inferior temporal and occipital cortices correlated with greater depressive symptoms, whereas increased FP in the right ventral caudate and the midbrain was associated with better working memory performance. A link between inflammatory and metabolic variables, with a particular emphasis on monocytes, and FP in obesity was also evidenced by Boruta analysis. CONCLUSIONS: Increased brain perfusion in individuals with obesity is associated with cognitive function and mental health through interaction with metabolic and inflammatory factors.

Altered brain functional connectivity in relation to perception of scrutiny in social anxiety disorder.

Although the fear of being scrutinized by others in a social context is a key symptom in social anxiety disorder (SAD), the neural processes underlying the perception of scrutiny have not previously been studied by functional magnetic resonance imaging (fMRI). We used fMRI to map brain activation during a perception-of-scrutiny task in 20 SAD patients and 20 controls. A multi-dimensional analytic approach was used. Scrutiny perception was mediated by activation of the medial frontal cortex, insula-operculum region and cerebellum, and the additional recruitment of visual areas and the thalamus in patients. Between-group comparison demonstrated significantly enhanced brain activation in patients in the primary visual cortex and cerebellum. Functional connectivity mapping demonstrated an abnormal connectivity between regions underlying general arousal and attention. SAD patients showed significantly greater task-induced functional connectivity in the thalamo-cortical and the fronto-striatal circuits. A statistically significant increase in task-induced functional connectivity between the anterior cingulate cortex and scrutiny-perception-related regions was observed in the SAD patients, suggesting the existence of enhanced behavior-inhibitory control. The presented data indicate that scrutiny perception in SAD enhances brain activity in arousal-attention systems, suggesting that fMRI may be a useful tool to explore such a behavioral dimension.

Neural correlates of fear conditioning and fear extinction and its association with cognitive-behavioral therapy outcome in adults with obsessive-compulsive disorder.

Recent neurobiological models of obsessive-compulsive disorder (OCD) have highlighted the potential role of abnormalities in fear learning processes. We compared brain activation -as assessed with whole-brain functional magnetic resonance imaging- during fear conditioning, fear extinction learning, and fear extinction recall in patients with OCD (n = 18) and healthy controls (n = 18). We also investigated whether brain activation during any of these processes was associated with exposure-based cognitive-behavioral therapy (CBT) outcome in patients. Patients with OCD showed significantly lower brain activation in the right insulo-opercular region and the dorsal anterior cingulate cortex during fear conditioning in comparison to healthy controls. Moreover, brain activation in the right insula predicted CBT outcome, with lower activation predicting a better outcome. Brain activation during extinction learning or recall did not differ between patients and controls or predicted CBT outcome in patients. Our results suggest that neural activations during fear conditioning in patients with OCD are abnormal and predict CBT outcome.

Lower Locus Coeruleus MRI intensity in patients with late-life major depression.

BACKGROUND: The locus coeruleus (LC) is the major noradrenergic source in the central nervous system. Structural alterations in the LC contribute to the pathophysiology of different neuropsychiatric disorders, which may increase to a variable extent the likelihood of developing neurodegenerative conditions. The characterization of such alterations may therefore help to predict progression to neurodegenerative disorders. Despite the LC cannot be visualized with conventional magnetic resonance imaging (MRI), specific MRI sequences have been developed to infer its structural integrity. METHODS: We quantified LC signal Contrast Ratios (LCCRs) in late-life major depressive disorder (MDD) (n = 37, 9 with comorbid aMCI), amnestic Mild Cognitive Impairment (aMCI) (n = 21, without comorbid MDD), and healthy controls (HCs) (n = 31), and also assessed the putative modulatory effects of comorbidities and other clinical variables. RESULTS: LCCRs were lower in MDD compared to aMCI and HCs. While no effects of aMCI comorbidity were observed, lower LCCRs were specifically observed in patients taking serotonin/norepinephrine reuptake inhibitors (SNRIs). CONCLUSION: Our results do not support the hypothesis that lower LCCRs characterize the different clinical groups that may eventually develop a neurodegenerative disorder. Conversely, our results were specifically observed in patients with late-life MDD taking SNRIs. Further research with larger samples is warranted to ascertain whether medication or particular clinical features of patients taking SNRIs are associated with changes in LC neurons.

Gambling disorder seeking treatment patients and tobacco use in relation to clinical profiles.

OBJECTIVES: Tobacco smoking and gambling disorder (GD) often co-occur. However, few studies have assessed the extent to which cigarette smoking may serve to classify and/or better define GD behaviour profiles. METHODS: Among a large sample of n = 3,652 consecutive treatment-seeking patients with GD (91% men). Smokers were compared to non-smokers across different sociodemographic, clinical, psychopathological and personality variables. The effect sizes for the means and the proportion differences between the groups were estimated. An evaluation of the smoking changes over the last 15 years was also performed. RESULTS: From the total sample, 62.4% of gamblers reported tobacco use. A decreasing linear trend in tobacco use was observed within the studied period, women having a more irregular pattern. The use of tobacco was linked to the use of alcohol and other illegal drugs. Gamblers who smoke, as compared to those who don't, presented lower education levels, lower social position indexes and active employment. They were younger, with an earlier age of onset, shorter duration of the gambling behavior, higher GD severity, more psychological symptoms, higher scores in novelty seeking and lower scores in reward dependence, self-directedness and self-transcendence. CONCLUSIONS: Gamblers seeking treatment who smoke display particular social, clinical, psychological, temperamental and character features different from non-smoking gamblers, suggesting that the presence or absence of comorbid smoking condition in GD should always be considered when developing an optimal treatment, as gamblers who smoke might need treatment strategies different from non-smoking gamblers.

Psychopathogical status and personality correlates of problem gambling severity in sports bettors undergoing treatment for gambling disorder.

BACKGROUND AND AIMS: Sports betting has been barely explored independently from other gambling behaviors. Little evidence is available regarding the factors affecting its severity in a clinical sample. The current study explores new determinants for sports betting severity in Spain by the inclusion of psychopathological distress and personality factors. METHODS: A sample of 352 Spanish sports bettors undergoing treatment for gambling disorder was recruited. Multiple regression models were used to evaluate the effects of sociodemographic variables, the age of onset of gambling behavior, the global psychopathological distress (SCL-90R GSI) and the personality profile (TCI-R) on sports betting severity and their influence over frequency (bets per episode) and debts due to gambling. RESULTS: We found that older age, higher psychopathological distress, lower self-directedness level, and higher novelty seeking level were predictors of gambling severity in Spanish sports bettors. The highest betting frequency was found in men, with the lowest education levels but the highest social status, the highest psychopathological distress, reward dependence score, and self-transcendence trait and the lowest persistence score. Debts were also associated to higher score in cooperativeness as well as older age. DISCUSSION AND CONCLUSIONS: Our findings call for further exploration of factors affecting sports betting severity regarded as a separate gambling entity subtype, as some of the traditional factors typically found in gamblers do not apply to sports bettors or apply inversely in our country. Consequently, sports bettors might deserve specific clinical approaches to tackle the singularities of their gambling behavior.

Contribution of sex on the underlying mechanism of the gambling disorder severity.

Significant increasing prevalences have been observed in gambling disorder (GD) in the last decades. This study analyzed the underlying mechanisms of the gambling severity with path analysis (implemented through Structural Equation Modeling, SEM), and assessed the potential moderator effect of the patients' sex. A sample of n = 512 treatment-seeking patients was assessed for sociodemographics and clinical state previously to the treatment. Results obtained in two separate SEM (for men and women) revealed differences in the direct effects and the mediational links. Among the male subsample, higher GD severity was directly related to the higher cognitive bias and the younger age of onset of the problematic gambling, while impulsivity levels and age of onset achieved an indirect effect on the disordered gambling mediated by the cognitive bias. Among females, GD severity was directly increased by younger age of onset, higher cognitive bias and lower self-directedness, while lower socioeconomic positions, and higher levels in harm avoidance achieved an indirect effect on the gambling severity mediated also by the distortions related to the gambling activity. These results provide new empirical evidence for a better understanding of the GD etiology, suggesting that the underlying complex links mediating the GD severity are strongly related to the patients' sex. The results can also contribute to design more effectiveness and precise therapy programs of patient-centered care.

Moderator effect of sex in the clustering of treatment-seeking patients with gambling problems.

BACKGROUND: There are no studies based on a person-centered approach addressing sex-related differences in the characteristics of treatment-seeking patients with gambling disorder (GD). The main objective of the current study is to identify empirical clusters of GD based on several measures of the severity of gambling behavior, and considering the potential role of patient sex as a moderator. METHODS: An agglomerative hierarchical clustering method was applied to an adult sample of 512 treatment-seeking patients (473 men and 39 women) by using a combination of the Schwarz Bayesian Information Criterion and log-likelihood function. RESULTS: Three clusters were identified in the subsample of men: cluster M1 (low-mild gambling severity level, 9.1%), cluster M2 (moderate level, 60.9%), and cluster M3 (severe level, 30.0%). In the women subsample, two clusters emerged: cluster W1 (mild-moderate level, 64.1%), and cluster W2 (severe level, 35.9%). The most severe GD profiles were related to being single, multiple gambling preference for nonstrategic plus strategic games, early onset of the gambling activity, higher impulsivity levels, higher dysfunctional scores in the personality traits of harm avoidance, and self-directedness, and higher number of lifespan stressful life events (SLE). Differences between the empirical men and women clusters were found in different sociodemographic and clinical measurements. CONCLUSIONS: Men and women have distinct profiles regarding gambling severity that can be identified by a clustering approach. The sociodemographic and clinical characterization of each cluster by sex may help to establish specific preventive and treatment interventions.

[Cyclical hyperemesis secondary to cannabis abuse]. / Vómitos cíclicos secundarios al consumo de cannabis.

Cannabinoid hyperemesis is characterized by recurring episodes of nausea and vomiting, with a stereotyped pattern, related to cannabis consumption. This syndrome is a paradoxical reaction to cannabis that develops in susceptible chronic cannabis users after several years of exposure. There is a direct relationship between cannabis use and the onset of the hyperemesis and between cessation of cannabis use and symptom resolution. The first cases were described in 2004. Since then, several new cases have been reported, although there are few studies of this syndrome. We report a case of chronic cannabis use with nausea and cyclic vomiting for 7 years. The symptoms were relieved by hot baths. A complete gastroenterological study was performed and no alterations were found. Cannabis use and its cessation are related to the presence or absence of the symptoms.

Corpus callosum and prefrontal functions in adolescents with history of very preterm birth.

Very preterm (VPT) birth can account for thinning of the corpus callosum and poorer cognitive performance. Research findings about preterm and VPT adolescents usually describe a small posterior corpus callosum, although our research group has also found reductions of the anterior part, specifically the genu. The aim of the present study was to investigate the functional implications of this concrete reduction. Fifty-two VPT adolescents were compared with 52 adolescents born at term; there were no significant differences in age and gender, and socioeconomic status was similar between the groups. All participants underwent a magnetic resonance imaging (MRI) study and assessment of prefrontal functioning and vocabulary. The VPT group showed significant reductions of the genu, isthmus and splenium, as well as a significantly worse performance on category verbal fluency, executive functions, everyday memory and vocabulary. Although several parts of the corpus callosum correlated with some prefrontal functions, the genu was the part which principally explained these correlations. The subtest Vocabulary only correlated with the splenium. The relationship between genu and prefrontal functions and between splenium and vocabulary may be due to the fact that these parts of the corpus callosum connect prefrontal and posterior parietal cortex, respectively. The work presented here provides evidence of specific associations between reductions in the anterior corpus callosum (genu) and lower prefrontal functioning in VPT adolescents.

Patterns of cerebral white matter damage and cognitive impairment in adolescents born very preterm.

There is increasing evidence about the presence of white matter damage in subjects with a history of premature birth, even in those classified as good outcome because of an apparently normal development. Although intellectual performance is within normal limits in premature children it is significantly decreased compared to paired controls. The purpose of this study was to investigate the relationship between a lower performance intelligence quotient and white matter damage in preterm adolescents. The sample comprised 44 adolescents (mean age+/-S.D.: 14.4+/-1.6 years) born before 32 weeks of gestational age and 43 term-born adolescents (14.5+/-2.1 years). Individual voxel-based morphometry analyses demonstrated that 35/44 (80%) preterm subjects had white matter abnormalities. The centrum semiovale and the posterior periventricular regions were the most frequently affected areas. Correlation analysis showed that in preterms the performance intelligence quotient correlated with the whole-brain white matter volume (r=0.32; P=0.036) but not with grey matter volume. Complementary analysis showed that low scores in the Digit Symbol subtest, a measure of processing speed, in the preterm group correlated with reductions in white matter concentration. These results suggest that white matter damage is highly common and that it persists until adolescence. Hence, diffuse white matter loss may be responsible for performance intelligence quotient and processing speed decrements in subjects with very preterm birth.

Proton magnetic resonance spectroscopy reveals medial temporal metabolic abnormalities in adolescents with history of preterm birth.

Prematurity is associated with volumetric reductions in specific brain areas such as the hippocampus and with metabolic changes that can be detected by spectroscopy. Short echo time (35 ms) Proton magnetic resonance spectroscopy (1H MRS) was performed to assess possible medial temporal lobe metabolic abnormalities in 21 adolescents with preterm birth (mean age: 14.8, SD: 1.3) compared with an age-matched control sample (mean age: 14.8, SD: 1.6). 1H MRS spectra were analyzed with linear combination model fitting, obtaining the absolute metabolite concentrations for Creatine (Cr), and myo-inositol (Ins). In addition, the following metabolite sums were measured: total Cho (glycerophospho-choline + phosphocholine), total N-acetyl-aspartate + N-acetyl-aspartylglutamate (NA), and total Glx (glutamate + glutamine). A stereological analysis was performed to calculate hippocampal volume. Absolute Cr, and total NA values were decreased in the preterm group (p = 0.016; p = 0.002, respectively). The preterm also showed a hippocampal reduction (p < 0.0001). Significant relationships were found between gestational age and different metabolites and the hippocampal volume. Moreover, hippocampal volume correlated with brain metabolites in the whole sample. Results demonstrate that prematurity affects medial temporal lobe metabolites, and that the alteration is related to structural changes, suggesting that the cerebral changes persist until adolescence.

Gestational age at preterm birth in relation to corpus callosum and general cognitive outcome in adolescents.

Prematurity is associated with corpus callosum abnormalities and low general cognitive functioning. The present study explores the specific relationship between gestational age, corpus callosum, and intelligence quotient (IQ) in a sample of preterm-born adolescents. Sixty-four adolescents born at a gestational age of 36 weeks or less were divided into 4 groups attending to their gestational age (GA) (group 1, < or = 27; group 2, 28-30; group 3, 31-33; group 4, 34-36). These individuals were compared with 53 adolescents born at term and of similar age, gender, and sociocultural status. Individuals born at a gestational age of 27 or less (group 1) presented a generalized corpus callosum reduction in the posterior part (posterior midbody, isthmus, and splenium) as well as in the anterior part (anterior midbody and genu), a reduced total white-matter volume, and a low Full-Scale IQ. Group 2 (GA between 28 and 30) also showed a low IQ, but corpus callosum reduction was only found in the splenium, without total white-matter volume reductions. Group 3 (GA between 31 and 33) did not present differences in corpus callosum size or a reduced total white- matter volume, but they showed a low Full-Scale IQ. Group 4 (GA between 34 and 36) did not show a smaller corpus callosum or a lower general cognitive performance. Specific significant correlations were found between corpus callosum subregions and gestational age. These results suggest the importance of gestational age in prematurity in relation to brain structural and functional outcome. Premature babies born at a gestational age of 27 weeks or less are the target group for long-term corpus callosum and white-matter anomalies and for a low IQ.

[Alcoholic jealousy: an old and current dilemma]. / Celopatía alcohólica: un antiguo y actual dilema.

The relation between alcohol and jealousy is a deeply rooted belief within the general population as well as in the medical, and particularly psychiatric, environment. Furthermore, in recent years there has been a growing interest on the forensic aspects of pathological jealousy, since they are a frequent cause of severe violence, homicide and suicide. Some authors have described a high prevalence of pathological jealousy in alcoholic patients, even awarding it a pathognomonic value in alcoholism. Nevertheless, recent studies do not completely support this relation, and draw attention to other factors. Results from the various studies contain several definitions and classifications of pathological jealousy, and although most of them highlight the prevalence of jealousy in alcoholic patients, they question its pathognomonic quality. Also, the presence of pathological jealousy in subjects with psychiatric disorders other than alcoholism is suggested, indicating the existence of predisposing and triggering factors which could explain the development of pathological jealousy. Yet, the important methodological difficulties in the published articles and the shortage of studies do not allow the confirmation of the alcoholic etiology in pathological jealousy; this is the reason why considering alcoholic jealousy as a separate entity is debatable. In this sense, the best diagnosis in these patients would be paranoid disorder combined with alcoholic dependence, hence, a dual diagnosis.

Brain alterations in low-frequency fluctuations across multiple bands in obsessive compulsive disorder.

The extent of functional abnormalities in frontal-subcortical circuits in obsessive-compulsive disorder (OCD) is still unclear. Although neuroimaging studies, in general, and resting-state functional Magnetic Resonance Imaging (rs-fMRI), in particular, have provided relevant information regarding such alterations, rs-fMRI studies have been typically limited to the analysis of between-region functional connectivity alterations at low-frequency signal fluctuations (i.e., <0.08 Hz). Conversely, the local attributes of Blood Oxygen Level Dependent (BOLD) signal across different frequency bands have been seldom studied, although they may provide valuable information. Here, we evaluated local alterations in low-frequency fluctuations across different oscillation bands in OCD. Sixty-five OCD patients and 50 healthy controls underwent an rs-fMRI assessment. Alterations in the fractional amplitude of low-frequency fluctuations (fALFF) were evaluated, voxel-wise, across four different bands (from 0.01 Hz to 0.25 Hz). OCD patients showed decreased fALFF values in medial orbitofrontal regions and increased fALFF values in the dorsal-medial prefrontal cortex (DMPFC) at frequency bands <0.08 Hz. This pattern was reversed at higher frequencies, where increased fALFF values also appeared in medial temporal lobe structures and medial thalamus. Clinical variables (i.e., symptom-specific severities) were associated with fALFF values across the different frequency bands. Our findings provide novel evidence about the nature and regional distribution of functional alterations in OCD, which should contribute to refine neurobiological models of the disorder. We suggest that the evaluation of the local attributes of BOLD signal across different frequency bands may be a sensitive approach to further characterize brain functional alterations in psychiatric disorders.

Distinct Subcortical Volume Alterations in Pediatric and Adult OCD: A Worldwide Meta- and Mega-Analysis.

OBJECTIVE: Structural brain imaging studies in obsessive-compulsive disorder (OCD) have produced inconsistent findings. This may be partially due to limited statistical power from relatively small samples and clinical heterogeneity related to variation in illness profile and developmental stage. To address these limitations, the authors conducted meta- and mega-analyses of data from OCD sites worldwide. METHOD: T1 images from 1,830 OCD patients and 1,759 control subjects were analyzed, using coordinated and standardized processing, to identify subcortical brain volumes that differ between OCD patients and healthy subjects. The authors performed a meta-analysis on the mean of the left and right hemisphere measures of each subcortical structure, and they performed a mega-analysis by pooling these volumetric measurements from each site. The authors additionally examined potential modulating effects of clinical characteristics on morphological differences in OCD patients. RESULTS: The meta-analysis indicated that adult patients had significantly smaller hippocampal volumes (Cohen's d=-0.13; % difference=-2.80) and larger pallidum volumes (d=0.16; % difference=3.16) compared with adult controls. Both effects were stronger in medicated patients compared with controls (d=-0.29, % difference=-4.18, and d=0.29, % difference=4.38, respectively). Unmedicated pediatric patients had significantly larger thalamic volumes (d=0.38, % difference=3.08) compared with pediatric controls. None of these findings were mediated by sample characteristics, such as mean age or scanning field strength. The mega-analysis yielded similar results. CONCLUSIONS: The results indicate different patterns of subcortical abnormalities in pediatric and adult OCD patients. The pallidum and hippocampus seem to be of importance in adult OCD, whereas the thalamus seems to be key in pediatric OCD. These findings highlight the potential importance of neurodevelopmental alterations in OCD and suggest that further research on neuroplasticity in OCD may be useful.