Some children with autism spectrum disorders (ASD; 15% to 30% of patients) show a significant and persistent regression in speech and social function during early childhood. There are no established treatments for the regressive symptoms. However, there are some known causes of this type of regression, such as Rett syndrome and Landau-Kleffner syndrome (LKS). In LKS, steroids have been used as a treatment. Some evidence suggests an autoimmune contribution to the pathophysiology of autism (Chez MG, Guido-Estrada N: Immune therapy in autism: historical experience and future directions with immunomodulatory therapy. Neurotherapeutics 2010, 7:293–301, Wasilewska J, Kaczmarski M, Stasiak-Barmuta A, Tobolczyk J, Kowalewska E: Low serum IgA and increased expression of CD23 on B lymphocytes in peripheral blood in children with regressive autism aged 3-6 years old. Arch Med Sci 2012, 8:324–331, Stefanatos G: Changing perspectives on Landau-Kleffner syndrome. Clin Neuropsychol 2011, 25:963–988), raising the possibility that steroids might be a useful therapy for regression in ASD. A retrospective study published in BMC Neurology by Duffy et al. (Duffy, et al: Corticosteroid therapy in regressive autism: A retrospective study of effects on the Frequency Modulated Auditory Evoked Response (FMAER), language, and behavior. BMC Neurol 2014, 14:70) reviewed 20 steroid treated R-ASD (STAR) patients and 24 ASD control patients not treated with steroids (NSA). Improvements in clinical function and in a neurophysiological biomarker were seen in the steroid-treated children pre- to post-prednisolone treatment. This research provides a rationale for a randomized trial with steroid therapy to determine the longer term benefits and complications of steroids in this population.
Please see related article http://www.biomedcentral.com/1471-2377/14/70/abstract.
Autism; Regression; Corticosteroids; FMAER; Language; Behavior
In women with chronic schizophrenia, higher levels of peripheral oxytocin have been associated with lower levels of positive but not negative symptoms. Sex-specific associations between endogenous levels of oxytocin (OT) and arginine-vasopressin (AVP) with clinical symptoms and cognition in untreated early course patients have not been examined.
Clinical ratings and neuropsychological testing were performed in thirty-eight acutely ill, unmedicated first-episode schizophrenia patients (14 women, 24 men). Serum hormone assays were obtained in patients and thirty-eight demographically similar healthy controls.
Patients demonstrated increased AVP levels compared to controls (p=0.01). Higher AVP levels were associated with greater positive symptoms (r=0.58, p=0.03) and worse verbal learning (r=−0.63, p=0.02) in female, but not male, patients. OT levels did not statistically differ between patients and controls, and were unrelated to clinical symptoms or cognition in patients.
Results suggest an association of endogenous AVP with increased positive symptom severity and worse cognition in untreated female, but not male, schizophrenia patients. Findings support the role of neuroendocrine alterations in acute psychosis and the importance of examining sex-specific neuroendocrine alterations early in the course of schizophrenia.
oxytocin; vasopressin; symptoms; verbal learning; schizophrenia; sex differences
The neurobiology of suicide is largely unknown. Studies of white matter tracts in patients with a history of suicidal behaviour have shown alteration in the left anterior limb of the internal capsule (ALIC). Our aim was to determine whether particular target fields of fibre projections through the ALIC are affected in depressed patients who recently attempted suicide.
We studied patients with major depressive disorder (MDD) with and without a history of suicide attempts and healthy controls using diffusion tensor imaging (DTI) and deterministic tractography to generate fibre tract maps for each participant. Tract voxels were coded as being unique to the left ALIC. We compared the mean percentage of fibres projecting to relevant brain regions in the 3 groups using analysis of covariance.
We included 63 patients with MDD (23 with and 40 without a history of suicide attempts) and 46 controls in our study. Both groups of depressed patients had reduced fibre projections through the ALIC to the left medial frontal cortex, orbitofrontal cortex and thalamus. Those with a history of suicide attempts had greater abnormalities than those without suicide attempts in the left orbitofrontal cortex and thalamus.
Diffusion tensor imaging deterministic tracking is unable to distinguish between afferent and efferent pathways, limiting our ability to distinguish the directionality of altered fibre tracts.
Frontothalamic loops passing through the ALIC are abnormal in patients with depression and significantly more abnormal in depressed patients with a history of suicide attempts than in those without a history of suicide attempts. Abnormal projections to the orbitofrontal cortex and thalamus may disrupt affective and cognitive functions to confer a heightened vulnerability for suicidal behaviour.
Schizophrenia and bipolar disorder share overlapping symptoms and genetic etiology. Functional brain dysconnectivity is seen in both disorders.
We compared 70 schizophrenia and 64 psychotic bipolar probands, their respective unaffected first-degree relatives (N= 70 and 52) and 118 healthy subjects, all group age-, sex- and ethnicity-matched. We used functional network connectivity (FNC) analysis to measure differential connectivity among 16 fMRI RSNs. First, we examined connectivity differences between probands and controls. Next, we probed these dysfunctional connections in relatives for potential endophenotypes. Network connectivity was then correlated with PANSS scores to reveal clinical relationships.
Three different network pairs were differentially connected in probands (FDR-corrected q<0.05) involving 5 individual resting-state networks: (A) Fronto/Occipital, (B) anterior Default Mode/Prefrontal, (C) Meso/Paralimbic, (D) Fronto-Temporal/Paralimbic & (E) Sensory-motor. One abnormal pair was unique to schizophrenia, (C-E), one unique to bipolar, (C-D) and one (A-B) shared. Two of these 3 combinations (A-B, C-E) were also abnormal in bipolar relatives, but none in schizophrenia relatives (non-significant trend for C-E). The Paralimbic circuit (C-D), that uniquely distinguished bipolar probands, contained multiple mood-relevant regions. Network relationship C-D correlated significantly with PANSS negative scores in bipolar probands and A-B was correlated to PANSS positive and general scores in schizophrenia.
Schizophrenia and psychotic bipolar probands share several abnormal RSN connections, but there are also unique neural network underpinnings between disorders. We identified specific connections and clinical relationships that may also be candidate psychosis endophenotypes, although these do not segregate straightforwardly with conventional diagnoses.
resting state; default mode; schizophrenia; bipolar; functional connectivity; gene; relatives
Restricted and repetitive behaviors, and a pronounced preference for behavioral and environmental consistency, are distinctive characteristics of autism spectrum disorders (ASD). Whether these clinical features of ASD are related to fundamental neuropsychological impairments in behavioral flexibility remains to be clarified.
Forty-one individuals with ASD and 37 matched controls performed a probabilistic reversal learning task to assess behavioral flexibility. Participants learned to choose the correct stimulus location from a pair of locations to win points (acquisition). After making the correct choice over multiple trials, the rewarded stimulus location changed without warning (reversal). Feedback was provided on an 80:20 probabilistic schedule, with 80% of correct choices and 20% of incorrect choices randomly reinforced.
ASD and control participants performed comparably during acquisition. At reversal, ASD participants initially chose the new correct location as quickly as controls, but then more frequently reverted back to the previously preferred response. The ASD group also more frequently shifted back to the previous response choice immediately following intermittent non-reinforcement of the new correct response. The number of regressive errors was positively correlated with independently ascertained clinical ratings of restricted and repetitive behaviors, but not other core features of ASD.
Restricted and repetitive behaviors in ASD are associated with neurocognitive deficits in flexible choice behavior. Preclinical research has established that frontostriatal circuitry supports flexibility on reversal learning tasks. Thus, alterations in this circuitry may contribute to behavioral rigidity in ASD and represent a target for therapeutic intervention.
autism; behavioral flexibility; reversal learning; restricted and repetitive behaviors
Reduced amplitude of the P300 event-related potential in auditory oddball tasks may characterize schizophrenia (SZ), but is also reported in bipolar disorder. Similarity of auditory processing abnormalities between these diagnoses is uncertain given the frequent combination of both psychotic and nonpsychotic patients in bipolar samples; abnormalities may be restricted to psychosis. In addition, typically only latency and amplitude of brain responses at selected sensors and singular time-points are used to characterize neural responses. Comprehensive quantification of brain activations involving both spatio-temporal and time-frequency analyses could better identify unique auditory oddball responses among patients with different psychotic disorders.
Sixty SZ, 60 bipolar I with psychosis (BPP), and 60 healthy subjects (H) were compared on neural responses during an auditory oddball task using multi-sensor electroencephalography. Principal components analysis was used to reduce multi-sensor data prior to evaluating group differences on voltage and frequency of neural responses over time.
Linear discriminant analysis revealed five variables that best differentiated groups: (i) late beta activity to standard stimuli and (ii) late beta/gamma activity to targets discriminated BPP from other groups; (iii) mid-latency theta/alpha activity to standards and (iv) target-related voltage at the late N2 response discriminated both psychosis groups from H; and (v) target-related voltage during early N2 discriminated BPP from H.
Although the P300 significantly differentiated psychotic groups from H, it did not uniquely discriminate groups beyond the above variables. No variable uniquely discriminated SZ, perhaps indicating utility of this task for studying psychosis-associated neurophysiology generally and BPP specifically.
ERP; auditory oddball; psychosis; time-frequency; P300; PCA
Stress responses have been studied extensively in animal models, but effects of major life stress on the human brain remain poorly understood. The aim of this study was to determine whether survivors of a major earthquake, who were presumed to have experienced extreme emotional stress during the disaster, demonstrate differences in brain anatomy relative to individuals who have not experienced such stressors.
Healthy survivors living in an area devastated by a major earthquake and matched healthy controls underwent 3-dimentional high-resolution magnetic resonance imaging (MRI). Survivors were scanned 13–25 days after the earthquake; controls had undergone MRI for other studies not long before the earthquake. We used optimized voxel-based morphometry analysis to identify regional differences of grey matter volume between the survivors and controls.
We included 44 survivors (17 female, mean age 37 [standard deviation (SD) 10.6] yr) and 38 controls (14 female, mean age 35.3 [SD 11.2] yr) in our analysis. Compared with controls, the survivors showed significantly lower grey matter volume in the bilateral insula, hippocampus, left caudate and putamen, and greater grey matter volume in the bilateral orbitofrontal cortex and the parietal lobe (all p < 0.05, corrected for multiple comparison).
Differences in the variance of survivor and control data could impact study findings.
Acute anatomic alterations could be observed in earthquake survivors in brain regions where functional alterations after stress have been described. Anatomic changes in the present study were observed earlier than previously reported and were seen in prefrontal–limbic, parietal and striatal brain systems. Together with the results of previous functional imaging studies, our observations suggest a complex pattern of human brain response to major life stress affecting brain systems that modulate and respond to heightened affective arousal.
Hospital readmission within 30-days of an index hospitalization is receiving increased scrutiny as a marker of poor quality patient care. This study identifies factors associated with 30-day readmission following General Surgery procedures.
Using standard National Surgical Quality Improvement Project (NSQIP) protocol, preoperative, intraoperative, and postoperative outcomes were collected on patients undergoing inpatient General Surgery procedures at a single academic center between 2009 and 2011. Data were merged with our institutional clinical data warehouse to identify unplanned 30-day readmissions. Demographics, comorbidities, type of procedure, postoperative complications, and ICD-9 coding data were reviewed for patients who were readmitted. Univariate and multivariate analysis was utilized to identify risk factors associated with 30-day readmission.
1442 General Surgery patients were reviewed. 163 (11.3%) were readmitted within 30 days of discharge. The most common reasons for readmission were gastrointestinal complaint/complication (27.6%), surgical infection (22.1%), and failure to thrive/malnutrition (10.4%). Comorbidities associated with risk of readmission included disseminated cancer, dyspnea, and preoperative open wound (p<0.05 for all variables). Surgical procedures associated with higher rates of readmission included pancreatectomy, colectomy, and liver resection. Postoperative occurrences leading to increased risk of readmission were blood transfusion, postoperative pulmonary complication, wound complication, sepsis/shock, urinary tract infection, and vascular complications. Multivariable analysis demonstrates that the most significant independent risk factor for readmission is the occurrence of any postoperative complication (OR 4.20, 95% CI 2.89–6.13).
Risk factors for readmission after General Surgery procedures are multi-factorial; however, postoperative complications appear to drive readmissions in surgical patients. Taking appropriate steps to minimize postoperative complications will decrease postoperative readmissions.
Postoperative Readmission; Complications; Risk Factors; General Surgery
White matter microstructure, known to undergo significant developmental transformation, is abnormal in bipolar disorder (BD). Available evidence suggests that white matter deviation may be more pronounced in pediatric than adult onset BD. This study aimed to examine how white matter microstructure deviates from a typical maturational trajectory in BD.
Fractional anisotropy (FA) was measured in 35 individuals presenting with first episode BD (type I) and 46 healthy controls (HC) (aged 9–42) using diffusion tensor imaging (DTI). Patients were medication free and close to illness onset at the time of DTI scans. Tract based spatial statistics were used to examine the center of white matter tracts, and FA was extracted from nine tracts of interest. Axial, radial, and mean diffusivity were examined in post-hoc analyses.
The left anterior limb of the internal capsule (ALIC) showed significantly lower FA in pediatric than adult onset BD. The lower FA in BD was due primarily to greater radial rather than a decrease in axial diffusivity.
ALIC connects the frontal lobes with archistriatum, thalamus, and medial temporal regions, and alteration in these pathways may contribute to mood dysregulation in BD. Abnormalities in this pathway appear to be associated with an earlier onset of illness and thus may reflect a greater liability for illness.
diffusion tensor imaging; development; limbic system; anterior limb of internal capsule; affect network
Impaired profiles of neurocognitive function have been consistently demonstrated among pediatric patients with bipolar disorder (BD), and may aid in the identification of endophenotypes across subtypes of the disorder. This study aims to determine phenotypic cognitive profiles of patients with BD Type I and II.
Subjects (N=79) consisted of BD I (n=27) and BD II (n=19) patients and demographic and intellectually matched healthy controls (HC; n=33) that completed a battery of neurocognitive tasks.
BD I patients performed significantly more poorly compared to HC on all domains of cognitive function including attention, executive function, working memory, visual memory, and verbal learning and memory. BD I patients also performed more poorly compared to BD II patients on all domains of cognitive functioning with the exception of working memory, whereas BD II patients did poorly relative to HC only on verbal learning and memory.
Findings from the current study indicate that BD I patients are characterized by more severe cognitive impairment relative to BD II patients who show an intermediate pattern of performance between BD I patients and HC. Verbal learning and memory may effectively differentiate pediatric BD patients and controls, regardless of the subtype of BD, and may serve as a cognitive endophenotype for the disorder. Additionally, these findings move us closer to developing effective cognitive interventions tailored to specific subtypes of pediatric BD patients.
Pediatric bipolar disorder; neurocognitive function; bipolar I disorder; bipolar II disorder; clinical subtypes
There has been significant advancement in various aspects of scientific knowledge concerning the role of cerebellum in the etiopathogenesis of autism. In the current consensus paper, we will observe the diversity of opinions regarding the involvement of this important site in the pathology of autism. Recent emergent findings in literature related to cerebellar involvement in autism are discussed, including: cerebellar pathology, cerebellar imaging and symptom expression in autism, cerebellar genetics, cerebellar immune function, oxidative stress and mitochondrial dysfunction, GABAergic and glutamatergic systems, cholinergic, dopaminergic, serotonergic, and oxytocin related changes in autism, motor control and cognitive deficits, cerebellar coordination of movements and cognition, gene-environment interactions, therapeutics in autism and relevant animal models of autism. Points of consensus include presence of abnormal cerebellar anatomy, abnormal neurotransmitter systems, oxidative stress, cerebellar motor and cognitive deficits, and neuroinflammation in subjects with autism. Undefined areas or areas requiring further investigation include lack of treatment options for core symptoms of autism, vermal hypoplasia and other vermal abnormalities as a consistent feature of autism, mechanisms underlying cerebellar contributions to cognition, and unknown mechanisms underlying neuroinflammation.
The cerebellar vermis (lobules VI-VII) has been implicated in both postmortem and neuroimaging studies of autism spectrum disorders (ASD). This region maintains the consistent accuracy of saccadic eye movements and plays an especially important role in correcting systematic errors in saccade amplitudes such as those induced by adaptation paradigms. Saccade adaptation paradigms have not yet been used to study ASD. Fifty-six individuals with ASD and 53 age-matched healthy controls performed an intrasaccadic target displacement task known to elicit saccadic adaptation reflected in an amplitude reduction. The rate of amplitude reduction and the variability of saccade amplitude across 180 adaptation trials were examined. Individuals with ASD adapted slower than healthy controls, and demonstrated more variability of their saccade amplitudes across trials prior to, during and after adaptation. Thirty percent of individuals with ASD did not significantly adapt, whereas only 6% of healthy controls failed to adapt. Adaptation rate and amplitude variability impairments were related to performance on a traditional neuropsychological test of manual motor control. The profile of impaired adaptation and reduced consistency of saccade accuracy indicates reduced neural plasticity within learning circuits of the oculomotor vermis that impedes the fine-tuning of motor behavior in ASD. These data provide functional evidence of abnormality in the cerebellar vermis that converges with previous reports of cellular and gross anatomic dysmorphology of this brain region in ASD.
We investigated affect recognition and the impact of emotional valence on working memory (using happy, angry, and neutral faces) in pediatric patients with bipolar disorder (BD) and healthy controls (HC).
Subjects (N=70) consisted of unmedicated patients with BD type I (n=23) and type II (n=16) and matched HC (n=31). All subjects completed tasks of emotion recognition (Chicago Pediatric Emotional Acuity Task; Chicago PEAT) and working memory for happy, angry, and neutral faces (Affective N-Back Memory Task; ANMT).
Compared to HC, BD patients performed significantly more poorly when identifying the intensity of happy and angry expressions on the Chicago PEAT, and demonstrated working memory impairments regardless of the type of facial emotional stimuli. Pediatric BD patients displayed the most impaired accuracy and reaction time performance with negative facial stimuli relative to neutral stimuli, but did not display this pattern with positive stimuli. Only BD type I patients displayed working memory deficits, while both type I and type II patients displayed emotion identification impairments. Results remained significant after controlling for comorbid ADHD and mood state.
Both type I and type II BD youth demonstrate emotion identification deficits. BD youth also demonstrate working memory impairments for facial stimuli irrespective of emotional valence, however, working memory deficits were the most pronounced with negative emotional stimuli. These deficits appear to be specific to BD type I patients, and suggest therefore that a more severe form of illness is characterized by more severe social-cognitive impairment.
Pediatric bipolar disorder; ADHD; emotion identification; attention; working memory
Individuals with schizophrenia (SZ) or psychotic bipolar disorder (BPP) may share neurophysiological abnormalities as measured in auditory paired-stimuli paradigms with electroencephalography (EEG). Such investigations have been limited, however, by quantifying only event-related potential peaks and/or broad frequency bands at limited scalp locations without considering possible mediating factors (e.g., baseline differences). Results from 64-sensor EEG collected in 180 age- and gender-matched participants reveal (i) accentuated pre-stimulus gamma oscillations and (ii) reduced P2 amplitudes and theta/alpha oscillations to S1 among both SZ and BPP. Conversely (iii) N1s in SZ to S1 were reduced compared to healthy and BPP, while (iv) beta range oscillations 200–300 ms following S2 were accentuated in BPP but not SZ. Results reveal a pattern of both unique and shared neurophysiological phenotypes occurring within major psychotic diagnoses.
White matter abnormalities have been reported in bipolar disorder. The present study aimed to investigate white matter integrity in untreated first episode patients with psychotic bipolar disorder using diffusion tensor imaging, and to compare observations with those from untreated first episode schizophrenia patients.
Fractional anisotropy and mean diffusivity were measured in first episode psychotic patients with bipolar disorder (n = 13) or schizophrenia (n = 21) and healthy individuals (n = 18). Group differences were evaluated using voxel based morphometry. Axial and radial diffusivity were examined in regions with altered fractional anisotropy in post-hoc analyses.
Patients with bipolar disorder showed lower fractional anisotropy than healthy controls in several white matter tracts. Compared with schizophrenia patients, bipolar disorder patients showed lower fractional anisotropy in the cingulum, internal capsule, posterior corpus callosum, tapetum, and occipital white matter including posterior thalamic radiation and inferior longitudinal fasciculus/inferior fronto-occipital fasciculus. Lower fractional anisotropy in bipolar disorder was characterized by increased radial diffusion rather than axial diffusion along the orientation of fiber tracts. Across several white matter tracts, both patient groups showed greater mean diffusivity than healthy individuals.
Selectively increased radial diffusivity in bipolar disorder patients suggests structural disorganization in fiber tract coherence of neurodevelopmental origin or alterations in myelin sheaths along fiber tracts. In contrast, increased isotropic diffusion along white matter tracts in schizophrenia patients with alterations in both radial and axial diffusivity suggests increased water content outside of axonal space. Thus, the present results suggest that different pathophysiological mechanisms may underlie white matter microstructural abnormalities in bipolar disorder and schizophrenia.
diffusion tensor imaging; first episode psychosis; radial diffusivity; fractional anisotropy; mean diffusivity
The current study examined the impact of risperidone and divalproex on affective and working memory circuitry in patients with pediatric bipolar disorder (PBD).
This was a six-week double blind randomized trial of risperidone plus placebo vs. divalproex plus placebo for patients with mania (n=21; 13.6±2.5 years). The fMRI outcomes were measured using a block design affective N-back task with angry, happy and neutral face stimuli at baseline and at 6-week follow-up. Matched healthy controls (HC; n=15, 14.5±2.8 years) were also scanned twice.
Post hoc analyses on the significant interaction in a 3×2×2 ANOVA which included patient groups and HC revealed that the risperidone group showed greater activation after treatment in response to the angry face condition in the left subgenual anterior cingulate cortex (ACC) and striatum relative to the divalproex group. The divalproex group showed greater activation relative to the risperidone group in left inferior frontal gyrus and right middle temporal gyrus. Over the treatment course, the risperidone group showed greater change in activation in the left ventral striatum than the divalproex group, and the divalproex group showed greater activation change in left inferior frontal gyrus and right middle temporal gyrus than the risperidone group. Furthermore, each patient group showed increased activation relative to HC in fronto-striato-temporal regions over time. The happy face condition was potentially less emotionally challenging in this study and did not elicit notable findings.
When patients performed a working memory task under emotional duress inherent in the paradigm, divalproex enhanced activation in a fronto-temporal circuit while risperidone increased activation in the dopamine (D2) receptor-rich ventral striatum.
risperidone; divalproex; pediatric bipolar disorder; fMRI
Autism spectrum disorders (ASD) are a group of complex and heterogeneous developmental disorders involving multiple neural system dysfunctions. In an effort to understand neurophysiological substrates, identify etiopathophysiologically distinct subgroups of patients, and track outcomes of novel treatments with translational biomarkers, EEG (electroencephalography) studies offer a promising research strategy in ASD. Resting-state EEG studies of ASD suggest a U-shaped profile of electrophysiological power alterations, with excessive power in low-frequency and high-frequency bands, abnormal functional connectivity, and enhanced power in the left hemisphere of the brain. In this review, we provide a summary of recent findings, discuss limitations in available research that may contribute to inconsistencies in the literature, and offer suggestions for future research in this area for advancing the understanding of ASD.
Autism; Resting-state; EEG; Electroencephalography
There is increasing evidence for phenomenological, biological and genetic overlap between schizophrenia and bipolar disorder, bringing into question the traditional dichotomy between them. Neurobiological models linked to dimensional clinical data may provide a better foundation to represent diagnostic variation in neuropsychiatric disorders.
To capture the interaction between psychosis and affective symptoms dimensionally, we devised a brief descriptive scale based on the type and relative proportions of psychotic and affective symptoms over the illness course. The scale was administered to a series of 762 patients with psychotic disorders, including schizophrenia, schizoaffective and psychotic bipolar disorder assessed as part of the Bipolar- Schizophrenia Network for Intermediate Phenotypes (B-SNIP) study.
The resulting Schizo-Bipolar Scale scores across these disorders showed neither a clear dichotomy nor a simple continuous distribution. While the majority of cases had ratings close to prototypic schizophrenia or bipolar disorder, a large group (45% of cases) fell on the continuum between these two prototypes. .
Our data suggest a hybrid conceptualization model with a representation of cases with prototypic schizophrenia or bipolar disorder at the extremes, but a large group of patients on the continuum between them that traditionally would be considered schizoaffective. A dimensional approach, using the Schizo-Bipolar Scale, characterized patients across a spectrum of psychopathology. This scale may provide a valuable means to examine the relationships between schizophrenia and psychotic bipolar disorder.
schizophrenia; bipolar disorder; schizoaffective disorder; continuum
Previous findings indicate treatment with a selective serotonin reuptake inhibitor (SSRI) facilitates behavioral flexibility when conditions require inhibition of a learned response pattern. The present experiment investigated whether acute treatment with the SSRI, escitalopram, affects behavioral flexibility when conditions require inhibition of a naturally-biased response pattern (elevated conflict test) and/or reversal of a learned response pattern (spatial reversal learning). An additional experiment was carried out to determine whether escitalopram, at doses that affected behavioral flexibility, also reduced anxiety as tested in the elevated plus-maze. In each experiment, Long-Evans rats received an intraperitoneal injection of either saline or escitalopram (0.03, 0.3 or 1.0 mg/kg) 30 minutes prior to behavioral testing. Escitalopram, at all doses tested, enhanced acquisition in the elevated conflict test, but did not affect performance in the elevated plus-maze. Escitalopram (0.3 and 1.0 mg/kg) did not alter acquisition of the spatial discrimination, but facilitated reversal learning. In the elevated conflict and spatial reversal learning test, escitalopram enhanced the ability to maintain the relevant strategy after being initially selected. The present findings suggest that enhancing serotonin transmission with a SSRI facilitates inhibitory processes when conditions require a shift away from either a naturally-biased response pattern or a learned choice pattern.
serotonin; reversal learning; escitalopram; rats; anxiety; reward
Visual motion processing and its use for pursuit eye movement control represent a valuable model for studying the use of sensory input for action planning. In psychotic disorders, alterations of visual motion perception have been suggested to cause pursuit eye tracking deficits. We evaluated this system in functional neuroimaging studies of untreated first-episode schizophrenia (N=24), psychotic bipolar disorder patients (N=13) and healthy controls (N=20). During a passive visual motion processing task, both patient groups showed reduced activation in the posterior parietal projection fields of motion-sensitive extrastriate area V5, but not in V5 itself. This suggests reduced bottom-up transfer of visual motion information from extrastriate cortex to perceptual systems in parietal association cortex. During active pursuit, activation was enhanced in anterior intraparietal sulcus and insula in both patient groups, and in dorsolateral prefrontal cortex and dorsomedial thalamus in schizophrenia patients. This may result from increased demands on sensorimotor systems for pursuit control due to the limited availability of perceptual motion information about target speed and tracking error. Visual motion information transfer deficits to higher -level association cortex may contribute to well-established pursuit tracking abnormalities, and perhaps to a wider array of alterations in perception and action planning in psychotic disorders.
schizophrenia; psychotic bipolar disorder; functional imaging; sensory processing; action planning; extraretinal systems
Working memory for temporal order is a component of working memory that is especially dependent on striatal systems, but has not been extensively studied in schizophrenia. This study was designed to characterize serial order reproduction by adapting a spatial serial order task developed for nonhuman primate studies, while controlling for working memory load and whether responses were initiated freely (unpaced) or in an externally paced format. Clinically stable schizophrenia patients (n=27) and psychiatrically healthy individuals (n=25) were comparable on demographic variables and performance on standardized tests of immediate serial order recall (Digit Span, Spatial Span). No group differences were observed for serial order recall when read sequence reproduction was unpaced. However, schizophrenia patients exhibited significant impairments when responding was paced, regardless of sequence length or retention delay. Intact performance by schizophrenia patients during the unpaced condition indicates that prefrontal storage and striatal output systems are sufficiently intact to learn novel response sequences and hold them in working memory to perform serial order tasks. However, retention for newly learned response sequences was disrupted in schizophrenia patients by paced responding, when read-out of each element in the response sequence was externally controlled. The disruption of memory for serial order in paced read-out condition indicates a deficit in frontostriatal interaction characterized by an inability to update working memory stores and deconstruct ‘chunked’ information.
schizophrenia; working memory; sequential; serial order; paced responding
We previously reported that higher levels of peripheral oxytocin are associated with lower levels of positive, general, and overall symptoms in women but not men with schizophrenia. Here we investigate the influence of sex, sex steroid hormone fluctuations, and peripheral oxytocin levels on emotional processing in men and women with schizophrenia.
Twenty-two women with schizophrenia and 31 female controls completed the Penn Emotion Acuity Test (PEAT), a facial emotion recognition and perception task, during two menstrual cycle phases: 1) early follicular (Days 2–4; low estrogen/progesterone) and 2) midluteal (Days 20–22; high estrogen/progesterone). Twenty-six males with schizophrenia and 26 male controls completed testing at comparable intervals. We obtained plasma hormone assays of estrogen, progesterone, testosterone, and oxytocin.
No sex differences were noted on the PEAT. Plasma oxytocin levels did not fluctuate across phases of the menstrual cycle. However, female patients and controls more accurately identified facial emotions during the early follicular versus midluteal phase (p<0.05). Higher oxytocin levels related to perceiving faces as happier in both female patients (r=−0.46, p=0.04) and controls (r=−0.40, p=0.04) but not in men.
Like healthy women, women with schizophrenia demonstrate menstrual-cycle dependent fluctuations in recognizing emotional cues. Like healthy women, female patients with higher levels of oxytocin perceived faces as happier. Future studies need to address whether this sex-specific relationship is associated with trust and other positive emotions, and whether exogenous oxytocin might enhance mood states and social interaction in female or all schizophrenia patients.
oxytocin; schizophrenia; menstrual cycle; social cognition; emotion recognition; emotion perception
To determine the relative effects of risperidone and divalproex on brain function in pediatric mania. This is a double-blind 6-week fMRI trial with 24 unmedicated manic patients randomized to risperidone or divalproex, and 14 healthy controls (HC) matched for IQ and demographic factors (mean age: 13.1±3.3 years). A pediatric affective color matching task, in which subjects matched the color of a positive, negative or neutral word with one of two colored circles, was administered. The primary clinical measure was the Young Mania Rating Scale (YMRS). The risperidone group, relative to HC, showed an increase in activation from pre- to post-treatment in right pregenual and subgenual anterior cingulate cortex and decreased activation in bilateral middle frontal gyrus during the negative condition; and decreased activation in left inferior and medial, and right middle frontal gyri, left inferior parietal lobe, and right striatum with positive condition. In the divalproex group, relative to HC, there was an increased activation in right superior temporal gyrus in the negative condition; and in left medial frontal gyrus and right precuneus with the positive condition. Greater pre-treatment right amygdala activity with negative and positive condition in the risperidone group, and left amygdala activity with positive condition in divalproex group, predicted poor response on YMRS. Risperidone and divalproex yield differential patterns of prefrontal activity during an emotion processing task in pediatric mania. Increased amygdala activity at baseline is a potential biomarker predicting poor treatment response to both the risperidone and divalproex.
mania; child; treatment; medication; adolescent; prefrontal