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Articles by Diana O. Perkins in JoVE
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Measurement of Fronto-limbic Activity Using an Emotional Oddball Task in Children with Familial High Risk for Schizophrenia
Sarah J. Hart1,2, Joseph J. Shaffer1,3, Joshua Bizzell1,2, Mariko Weber1,3, Mary A. McMahon2, Hongbin Gu1, Diana O. Perkins1, Aysenil Belger1,2
1Department of Psychiatry, University of North Carolina at Chapel Hill School of Medicine, 2Duke-UNC Brain Imaging and Analysis Center, Duke University Medical Center, 3Curriculum in Neurobiology, University of North Carolina at Chapel Hill
This paper describes how to use the emotional oddball task and fMRI to measure brain activation in children and adolescents at familial high risk for schizophrenia (FHR). FMRI was used to measure differences in fronto-striato-limbic regions during an emotional oddball task. Children with FHR exhibited abnormal functional activation during adolescence.
Other articles by Diana O. Perkins on PubMed
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Evaluating and Treating the Prodromal Stage of Schizophrenia
Current Psychiatry Reports.
Aug, 2004 |
Pubmed ID: 15260945 Identification of a person in the prodromal stage of schizophrenia, before the onset of the first episode of psychosis, provides an opportunity for early, potentially preventative, interventions. Recent attempts to develop "at risk" or "prodromal syndrome" diagnostic criteria have proved to be successful at identifying individuals at high risk for psychosis. Preliminary investigations find that pharmacologic and psychotherapeutic interventions may reduce the risk of psychosis in "at risk" individuals, but until more is known, current treatment guidelines recommend close monitoring, therapeutic interventions that address identified problems, including supportive or cognitive therapies to reduce the functional consequences of the presenting symptoms, family interventions to reduce family distress and improve coping, and intervention with schools to decrease likelihood of school failure. Pharmacologic intervention targeting the prodromal symptoms is not recommended, given the uncertain risk-benefit ratio.
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Changes in Neuropsychological Functioning with Progression of HIV-1 Infection: Results of an 8-year Longitudinal Investigation
AIDS and Behavior.
Sep, 2004 |
Pubmed ID: 15475681 Despite the advent of more effective treatments for HIV-1 infection, cognitive impairment is still frequent and questions remain regarding which areas of impairment are more common in the different disease stages. This study investigated cognitive performance over an 8-year period of time in 59 HIV-1 seropositive (HIV-1+) men who were clinically asymptomatic at study entry, in comparison to a cohort of 55 HIV-1 seronegative (HIV-1-) men. Every 6 months we examined cognitive functioning in 5 domains-fine motor speed, attention, verbal memory, executive functioning, and speed of information processing. We found that patients with AIDS scored significantly worse on fine motor speed and speed of information processing than HIV-1- individuals and the HIV-1+ non-AIDS patients. In addition, the HIV-1+ non-AIDS patients performed more poorly than the HIV-1- group on speed of information processing. Depressive symptoms were also associated with diminished performance on measures of attention, executive functioning, and speed of information processing. Further research is needed to examine the effects of disease stage and depression on cognitive impairment in the era of new HIV treatments.
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Folded RNA from an Intron of One Gene Might Inhibit Expression of a Counteracting Gene
In Silico Biology.
2005 |
Pubmed ID: 16268785 Homeostatic maintenance of mRNA levels including prompt availability of mRNAs for translation in response to changing protein demands might be partly enabled by a system of combinatorial controls involving noncoding RNA blocking agents. This article proposes a specific version of that control mechanism, namely, a double-stranded RNA folding from transcription of an intron of one gene might and leading to an agent that inhibits mRNA of a counteracting gene. Thus transcription of the first gene would automatically repress translation of the second. On the basis of a bioinformatics search, we suggest a possible example, namely, that pro-apoptosis gene PAR4 might inhibit anti-apoptosis gene XIAP. Part of an intron from PAR4 folds to form a large, stable hairpin, and reverse complement of the hairpin stem (with approximately 280 nucleotides) matches a sub-sequence of an exon in XIAP. This would be part of an efficient system to drive initiated apoptosis to its conclusion. Figuratively speaking, it replaces two control knobs with one. Since repeats, some with many thousands of copies, occur throughout the genome with complex distributions, care must be taken before asserting that the presence of any repeat in any gene is significant. Our apoptosis example involves repeats, so experimental verification is needed and planned. However, if it is found that the noncoding RNA by-product of one gene folds into a hairpin that is processed into an agent that inhibits a counteracting gene, then the same type of control unit might be found extensively among counteracting families of genes of many types.
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Effectiveness of Olanzapine, Quetiapine, Risperidone, and Ziprasidone in Patients with Chronic Schizophrenia Following Discontinuation of a Previous Atypical Antipsychotic
The American Journal of Psychiatry.
Apr, 2006 |
Pubmed ID: 16585435 In the treatment of schizophrenia, changing antipsychotics is common when one treatment is suboptimally effective, but the relative effectiveness of drugs used in this strategy is unknown. This randomized, double-blind study compared olanzapine, quetiapine, risperidone, and ziprasidone in patients who had just discontinued a different atypical antipsychotic.
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Baseline Neurocognitive Deficits in the CATIE Schizophrenia Trial
Neuropsychopharmacology : Official Publication of the American College of Neuropsychopharmacology.
Sep, 2006 |
Pubmed ID: 16641947 Neurocognition is moderately to severely impaired in patients with schizophrenia. However, the factor structure of the various neurocognitive deficits, the relationship with symptoms and other variables, and the minimum amount of testing required to determine an adequate composite score has not been determined in typical patients with schizophrenia. An 'all-comer' approach to cognition is needed, as provided by the baseline assessment of an unprecedented number of patients in the CATIE (Clinical Antipsychotic Trials of Intervention Effectiveness) schizophrenia trial. From academic sites and treatment providers representative of the community, 1493 patients with chronic schizophrenia were entered into the study, including those with medical comorbidity and substance abuse. Eleven neurocognitive tests were administered, resulting in 24 individual scores reduced to nine neurocognitive outcome measures, five domain scores and a composite score. Despite minimal screening procedures, 91.2% of patients provided meaningful neurocognitive data. Exploratory principal components analysis yielded one factor accounting for 45% of the test variance. Confirmatory factor analysis showed that a single-factor model comprised of five domain scores was the best fit. The correlations among the factors were medium to high, and scores on individual factors were very highly correlated with the single composite score. Neurocognitive deficits were modestly correlated with negative symptom severity (r=0.13-0.27), but correlations with positive symptom severity were near zero (r
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Clinical Trials in Schizophrenia with Results for the Real World
CNS Spectrums.
Jul, 2006 |
Pubmed ID: 16816795 Most clinical data for antipsychotics come from studies designed to test the efficacy and safety of the drugs under ideal conditions, in limited subgroups of patients. In contrast, practical clinical trials (PCTs) are designed to test the effectiveness of different treatment options under conditions that more accurately reflect actual clinical practice. Consequently, PCTs are able to provide information that can be utilized by healthcare providers and other decision makers. Characteristics of PCTs include a clinically relevant question, a representative sample of patients and practice settings, sufficient power to identify modest relevant effects, randomization to protect against bias, uncertainty regarding the outcome of treatment, assessment and treatment protocols that enact best clinical practices, simple and relevant outcomes, and limited subject and investigator burden. The Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) research program is an example of a PCT. The CATIE study illustrates how PCTs, when properly designed, might be helpful in informing clinical decision making. Because the CATIE study was designed to reflect the effectiveness of antipsychotics under naturalistic clinical conditions, its results should have particular applicability to the arena of clinical practice. This article provides a discussion of the differences between efficacy and effectiveness studies. In assessing the practical utility of results from the CATIE study, much can be learned on how to shape future studies of effectiveness so as to better generate data that are applicable to the "real world."
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North American Prodrome Longitudinal Study: a Collaborative Multisite Approach to Prodromal Schizophrenia Research
Schizophrenia Bulletin.
May, 2007 |
Pubmed ID: 17255119 This article presents the rationale, design, and preliminary findings of the North American Prodrome Longitudinal Study (NAPLS), a collaborative, multisite investigation into the earliest phase of psychotic illness. We describe how 8 independently conceived research projects were integrated methodologically, how diagnostic reliability was achieved across sites on the Structured Interview for Prodromal Syndromes, and how baseline and follow-up data were aggregated for 888 at risk and comparison subjects. Data are presented describing the demographic, academic/work, and diagnostic characteristics of 3 relevant subgroups: persons at heightened clinical risk for psychosis, help-seeking comparison subjects, and nonpsychiatric controls. The NAPLS data set will be used to explore a series of questions related to prodromal psychosis, including the descriptive phenomenology of currently accepted diagnostic criteria, conversion rates over a 30-month period, predictors of psychosis onset and functional disability, and the impact of early treatment on the course of prodromal symptoms.
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Neuroprotection: a Therapeutic Strategy to Prevent Deterioration Associated with Schizophrenia
CNS Spectrums.
Mar, 2007 |
Pubmed ID: 17329984 Schizophrenia is a neurodevelopmental disorder associated with persistent symptomatology, severe functional disability, and residual morbidity characteristic of neurodegenerative brain diseases. The illness begins with genetic susceptibility and generally expresses itself after puberty through subtle changes that begin during the prodromal stage. Symptoms get progressively worse and tend to become more resistant to treatment with each relapse. Evidence for a neuroprotective effect of some forms of early treatment is beginning to emerge. While the underlying mechanisms remain uncertain, atypical antipsychotics may counteract some of the progressive deteriorative effects by enhancing synaptic plasticity and cellular resilience. However, identifying and treating patients in the earliest disease states presents methodological challenges as there is no consensus on the best methods of intervention and differences in at-risk children are not readily detectable or substantial enough to predict which ones will develop schizophrenia. In this expert roundtable supplement, Jeffrey A. Lieberman, MD, reviews the historical context of progressive deterioration in schizophrenia. Next, Diana O. Perkins, MD, MPH, reviews some of the challenges to early identification of illness as well as the impact of early versus delayed treatment. Finally, L. Fredrik Jarskog, MD, focuses on the neurobiology of functional progression in schizophrenia as well as pharmacology and the potential for neuroprotection.
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The Neuregulin 1 Promoter Polymorphism Rs6994992 is Not Associated with Chronic Schizophrenia or Neurocognition
American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics : the Official Publication of the International Society of Psychiatric Genetics.
Oct, 2008 |
Pubmed ID: 18286587 The neuregulin 1 (NRG1) promoter single nucleotide polymorphism (SNP) rs6994992 has shown association with decreased activation of frontal and temporal lobe regions, increased risk of psychosis, and decreased premorbid IQ. This SNP is part of a putative schizophrenia risk-associated haplotype and was associated with increased expression of the type IV transcript in postmortem tissue. We tested for association between rs6994992 and chronic schizophrenia by genotyping 738 cases from the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) and 733 matched controls. We further tested for associations with age at onset and baseline neurocognition in cases with schizophrenia reasoning that these phenotypes might yield results similar to those seen for premorbid IQ. Affection status was weakly associated with rs6994992 genotypes and trended towards association under a recessive model. This association did not survive correction for multiple comparisons and was in the opposite direction than has been reported. There was no association between rs6994992 and age at onset, an estimate of premorbid IQ, or neurocognition at study baseline. We were unable to replicate previous associations of rs6994992 with schizophrenia and, moreover, did not find significant associations with age of onset, an estimate of pre-morbid IQ, or neurocognition.
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Time-lapse Mapping of Cortical Changes in Schizophrenia with Different Treatments
Cerebral Cortex (New York, N.Y. : 1991).
May, 2009 |
Pubmed ID: 18842668 Using time-lapse maps, we visualized the dynamics of schizophrenia progression, revealing spreading cortical changes that depend on the type of antipsychotic treatment. Dynamic, 4-dimensional models of disease progression were created from 4 repeated high-resolution brain magnetic resonance imaging scans of 36 first-episode schizophrenia patients (30 men/6 women; mean age: 24.2 +/- 5.1 SD years) randomized to haloperidol (HAL) (n = 15) or olanzapine (OLZ) treatment (n = 21), imaged at baseline, 3, 6, and 12 months (144 scans). Based on surface-based cortical models and point-by-point measures of gray matter volume, we generated time-lapse maps for each treatment. Disease trajectories differed for atypical versus typical neuroleptic drugs. A rapidly advancing parietal-to-frontal deficit trajectory, in HAL-treated patients, mirrored normal cortical maturation but greatly intensified. The disease trajectory advanced even after symptom normalization, involving the frontal cortex within 12 months with typical drug treatment. Areas with fastest tissue loss shifted anteriorly in the first year of psychosis. This trajectory was not seen with OLZ. Whether this association reflects either reduced neurotoxicity or neuroprotection cannot be addressed with neuroimaging; changes may relate to glial rather than neural components. These maps revise current models of schizophrenia progression; due to power limitations, the findings require confirmation in a sample large enough to model group x time interactions.
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Proceedings and Data from The Schizophrenia Summit: a Critical Appraisal to Improve the Management of Schizophrenia
The Journal of Clinical Psychiatry.
2009 |
Pubmed ID: 19292973 In mid-February 2008, a panel of 10 nationally recognized schizophrenia research experts was assembled in a Schizophrenia Summit to focus on controversies that exist in treating patients with schizophrenia. The current literature related to the diagnosis and etiopathology of schizophrenia was evaluated regarding the identification of a prodromal phase, brain changes, cognitive impairments, genetic factors, and use of neuroimaging in patients with schizophrenia. Further, consideration was given to evidence supporting the neuroprotective benefits of atypical antipsychotic medications, the benefits of treating patients during the prodromal period, the use of combination antipsychotic medications, the need to improve cognitive function, and the management of substance abuse. Summit faculty member opinion is compared with field survey results, and recommendations are made for future research.
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Validity of the Prodromal Risk Syndrome for First Psychosis: Findings from the North American Prodrome Longitudinal Study
Schizophrenia Bulletin.
Sep, 2009 |
Pubmed ID: 19386578 Treatment and prevention studies over the past decade have enrolled patients believed to be at risk for future psychosis. These patients were considered at risk for psychosis by virtue of meeting research criteria derived from retrospective accounts of the psychosis prodrome. This study evaluated the diagnostic validity of the prospective "prodromal risk syndrome" construct. Patients assessed by the Structured Interview for Prodromal Syndromes as meeting criteria of prodromal syndromes (n = 377) from the North American Prodrome Longitudinal Study were compared with normal comparison (NC, n = 196), help-seeking comparison (HSC, n = 198), familial high-risk (FHR, n = 40), and schizotypal personality disorder (SPD, n = 49) groups. Comparisons were made on variables from cross-sectional demographic, symptom, functional, comorbid diagnostic, and family history domains of assessment as well as on follow-up outcome. Prodromal risk syndrome patients as a group were robustly distinguished from NC subjects across all domains and distinguished from HSC subjects and from FHR subjects on most measures in many of these domains. Adolescent and young adult SPD patients, while distinct from prodromal patients on definitional grounds, were similar to prodromals on multiple measures, consistent with SPD in young patients possibly being an independent risk syndrome for psychosis. The strong evidence of diagnostic validity for the prodromal risk syndrome for first psychosis raises the question of its evaluation for inclusion in Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition).
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The Relation of Antipsychotic and Antidepressant Medication with Baseline Symptoms and Symptom Progression: a Naturalistic Study of the North American Prodrome Longitudinal Sample
Schizophrenia Research.
Nov, 2009 |
Pubmed ID: 19709859 A substantial number of patients who meet criteria for a prodromal syndrome for first psychosis are treated with antipsychotic and/or antidepressant medications. There is suggestive evidence that both classes of medication may reduce prodromal symptoms. This longitudinal study examined the relation of antipsychotic and antidepressant medication with prodromal symptom severity at baseline and 6-month follow-up. Participants met Structured Interview for Prodromal Syndromes (SIPS) criteria for the prodrome, and were evaluated at eight centers as part of the North American Prodrome Longitudinal Study (NAPLS). Symptom ratings (positive, negative, disorganized and general) and data on antipsychotics, SSRIs, and other antidepressant medications were obtained at baseline and 6-month follow-up. Analyses revealed that all symptom dimensions declined in severity over time, but there were differences in the magnitude of the decline as a function of antipsychotic medication. Those never on antipsychotics showed less reduction in positive and disorganized symptoms over time. SSRIs and other antidepressants were not linked with declines in symptom severity. Consistent with findings from small-sample, clinical trials, the present results suggest that atypical antipsychotics may be effective in reducing the severity of attenuated positive symptoms associated with the prodrome to psychotic disorders. Limitations of the present study are noted, including the fact that it is not a randomized trial, and data on duration and dosage of medication and 2-year follow-up were not available for most participants. The results are discussed in light of the relative risks and benefits of preventive interventions, both medication and cognitive therapies, and the importance of future clinical trials.
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The Effects of Antipsychotic Medications on Emotion Perception in Patients with Chronic Schizophrenia in the CATIE Trial
Schizophrenia Research.
Nov, 2009 |
Pubmed ID: 19766459 Few pharmacological intervention studies have examined the impact of medication on social cognition, particularly emotion perception. The goal of this randomized, double-blind study is to compare the effects of several second generation antipsychotics and a first generation antipsychotic, perphenazine, on emotion perception in individuals with schizophrenia. Patients were assigned to receive treatment with olanzapine, queitapine fumarate, risperidone, ziprasidone or perphenazine for up to 18 months. Eight hundred and seventy three patients completed an emotion perception test immediately prior to randomization and after 2 months of treatment. We also examined baseline predictors of emotion perception change. Most treatments were associated with a small, non-statistically significant improvement in emotion perception at two months, although they did not differ from one another. Greater improvement in emotion perception at 2 months was significantly predicted by lower baseline emotion perception and higher baseline neurocognitive functioning, and marginally predicted by less time on an antipsychotic.
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Microduplications of 16p11.2 Are Associated with Schizophrenia
Nature Genetics.
Nov, 2009 |
Pubmed ID: 19855392 Recurrent microdeletions and microduplications of a 600-kb genomic region of chromosome 16p11.2 have been implicated in childhood-onset developmental disorders. We report the association of 16p11.2 microduplications with schizophrenia in two large cohorts. The microduplication was detected in 12/1,906 (0.63%) cases and 1/3,971 (0.03%) controls (P = 1.2 x 10(-5), OR = 25.8) from the initial cohort, and in 9/2,645 (0.34%) cases and 1/2,420 (0.04%) controls (P = 0.022, OR = 8.3) of the replication cohort. The 16p11.2 microduplication was associated with a 14.5-fold increased risk of schizophrenia (95% CI (3.3, 62)) in the combined sample. A meta-analysis of datasets for multiple psychiatric disorders showed a significant association of the microduplication with schizophrenia (P = 4.8 x 10(-7)), bipolar disorder (P = 0.017) and autism (P = 1.9 x 10(-7)). In contrast, the reciprocal microdeletion was associated only with autism and developmental disorders (P = 2.3 x 10(-13)). Head circumference was larger in patients with the microdeletion than in patients with the microduplication (P = 0.0007).
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Gene Processing Control Loops Suggested by Sequencing, Splicing, and RNA Folding
BMC Bioinformatics.
2010 |
Pubmed ID: 21167075 Small RNAs are known to regulate diverse gene expression processes including translation, transcription, and splicing. Among small RNAs, the microRNAs (miRNAs) of 17 to 27 nucleotides (nts) undergo biogeneses including primary transcription, RNA excision and folding, nuclear export, cytoplasmic processing, and then bioactivity as regulatory agents. We propose that analogous hairpins from RNA molecules that function as part of the spliceosome might also be the source of small, regulatory RNAs (somewhat smaller than miRNAs).
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Genome-wide Pharmacogenomic Study of Neurocognition As an Indicator of Antipsychotic Treatment Response in Schizophrenia
Neuropsychopharmacology : Official Publication of the American College of Neuropsychopharmacology.
Feb, 2011 |
Pubmed ID: 21107309 Neurocognitive deficits are a core feature of schizophrenia and, therefore, represent potentially critical outcome variables for assessing antipsychotic treatment response. We performed genome-wide association studies (GWAS) with 492K single nucleotide polymorphisms (SNPs) in a sample of 738 patients with schizophrenia from the Clinical Antipsychotic Trials of Intervention Effectiveness study. Outcome variables consisted of a neurocognitive battery administered at multiple time points over an 18-month period, measuring processing speed, verbal memory, vigilance, reasoning, and working memory domains. Genetic mediation of improvements in each of these five domains plus a composite neurocognitive measure was assessed for each of five antipsychotics (olanzapine, perphenazine, quetiapine, risperidone, and ziprasidone). Six SNPs achieved genome-wide significance using a pre-specified threshold that ensures, on average, only 1 in 10 findings is a false discovery. These six SNPs were located within, or in close proximity to, genes EHF, SLC26A9, DRD2, GPR137B, CHST8, and IL1A. The more robust findings, that is those significant across multiple neurocognitive domains and having adjacent SNPs showing evidence for association, were rs286913 at the EHF gene (p-value 6.99 × 10(-8), q-value 0.034, mediating the effects of ziprasidone on vigilance), rs11240594 at SLC26A9 (p-value 1.4 × 10(-7), q-value 0.068, mediating the effects of olanzapine on processing speed), and rs11677416 at IL1A (p-value 6.67 × 10(-7), q-value 0.081, mediating the effects of olanzapine on working memory). This study has generated several novel candidate genes for antipsychotic response. However, our findings will require replication and functional validation. To facilitate replication efforts, we provide all GWAS p-values for download.
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Nuclear and Cytoplasmic Localization of Neural Stem Cell MicroRNAs
RNA (New York, N.Y.).
Apr, 2011 |
Pubmed ID: 21363885 Although generally regarded as functional in the cytoplasm, a number of microRNAs (miRNAs) have been found in the nucleus, possibly with a role in gene regulation. Here we report that, in fact, a substantial fraction of all human miRNAs are present in the nucleus of neural stem cells. Further, subsets of these miRNAs display consistently higher standardized rank in the nucleus than in the cytoplasm of these cells, as identified with an RT-qPCR technology and confirmed by microarray analysis. Likewise, other miRNAs display higher cytoplasmic standardized ranks. Three samples were partitioned into nuclear and cytoplasmic fractions in six assays for 373 miRNAs. From the 100 most highly expressed miRNAs, standard scores of nuclear and cytoplasmic concentrations were determined. Among those, 21 miRNAs had all three nuclear standard scores higher than all three cytoplasmic scores; likewise, 31 miRNAs had consistently higher cytoplasmic scores. Random concentrations would result in only five in each set. Remarkably, if one miRNA has a high standard score in a compartment, then other miRNAs having the same 5' seeds and certain similar 3' end patterns are also highly scored in the same way. That is, in addition to the seed sequence, 3' sequence similarity criteria identify families of mature miRNAs with consistently high nuclear or cytoplasmic expression.
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Altered Age-related Trajectories of Amygdala-prefrontal Circuitry in Adolescents at Clinical High Risk for Psychosis: a Preliminary Study
Schizophrenia Research.
Jan, 2012 |
Pubmed ID: 22056201 Emotion processing deficits are prominent in schizophrenia and exist prior to the onset of overt psychosis. However, developmental trajectories of neural circuitry subserving emotion regulation and the role that they may play in illness onset have not yet been examined in patients at risk for psychosis. The present study employed a cross-sectional analysis to examine age-related functional activation in amygdala and prefrontal cortex, as well as functional connectivity between these regions, in adolescents at clinical high risk (CHR) for psychosis relative to typically developing adolescents. Participants (n=34) performed an emotion processing fMRI task, including emotion labeling, emotion matching, and non-emotional control conditions. Regression analyses were used to predict activation in the amygdala and ventrolateral prefrontal cortex (vlPFC) based on age, group, sex, and the interaction of age by group. CHR adolescents exhibited altered age-related variation in amygdala and vlPFC activation, relative to controls. Controls displayed decreased amygdala and increased vlPFC activation with age, while patients exhibited the opposite pattern (increased amygdala and decreased vlPFC activation), suggesting a failure of prefrontal cortex to regulate amygdala reactivity. Moreover, a psychophysiological interaction analysis revealed decreased amygdala-prefrontal functional connectivity among CHR adolescents, consistent with disrupted brain connectivity as a vulnerability factor in schizophrenia. These results suggest that the at-risk syndrome is marked by abnormal development and functional connectivity of neural systems subserving emotion regulation. Longitudinal data are needed to confirm aberrant developmental trajectories intra-individually and to examine whether these abnormalities are predictive of conversion to psychosis, and of later deficits in socioemotional functioning.
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North American Prodrome Longitudinal Study (NAPLS 2): Overview and Recruitment
Schizophrenia Research.
Dec, 2012 |
Pubmed ID: 23043872 The North American Prodrome Longitudinal Study (NAPLS) is a consortium of eight programs focusing on the psychosis prodrome. Funded by the National Institute of Mental Health (NIMH), the sites are located at Emory University, Harvard University, University of Calgary, UCLA, UCSD, University of North Carolina Chapel Hill, Yale University, and Zucker Hillside Hospital. Although the programs initially developed independently, they previously collaborated to combine their historical datasets and to produce a series of analyses on predictors of psychosis in one of the largest samples of longitudinally followed prodromal subjects worldwide. This led to the development of a five year prospective study "Predictors and Mechanisms of Conversion to Psychosis", (also known as NAPLS-2) with three major aims: (1) to prospectively test the prediction algorithm developed in NAPLS-1, (2) to investigate the neuroanatomical, neurophysiological, neurocognitive, and neurohormonal factors that may contribute to the development of psychosis, and (3) to develop a repository of DNA, RNA, and plasma from participants meeting diagnostic criteria for a clinical high risk (CHR) state and from demographically similar healthy subjects. Funded by NIMH in 2008, NAPLS-2 will generate the largest CHR for psychosis sample with 720 CHR and 240 healthy comparison subjects, and thus will provide statistical power and scientific scope that cannot be duplicated by any single site study. This paper describes the overall methodology of the NAPLS-2 project and reports on the ascertainment and demographics at the midway point of the study with (360 CHR) and 180 controls.
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Differences in Subcortical Structures in Young Adolescents at Familial Risk for Schizophrenia: a Preliminary Study
Psychiatry Research.
Nov, 2012 |
Pubmed ID: 23146250 Schizophrenia has been associated with reduced volumes of subcortical structures on magnetic resonance imaging (MRI), but the relation of these reductions to familial risk for the disorder is unclear. We investigated the effect of familial risk for schizophrenia on regional subcortical volumes during adolescence, a period marked by steep maturational changes in brain structure and the emergence of psychotic symptoms. A group of 26 non-help-seeking, first-degree relatives of patients with schizophrenia and 43 matched healthy comparisons, between 9 and 18 years of age, underwent MRI scanning and were rated for the presence of prodromal symptoms. Five subcortical regions-of-interest were tested for group differences and group by age interactions, as well as correlations with low-level prodromal symptoms in the familial risk group. Relative to comparisons, familial risk subjects demonstrated greater positive volume-age relationships in hippocampus, putamen, and globus pallidus. These results suggest that relatives of individuals with schizophrenia exhibit structural abnormalities in the subcortex as early as pre-adolescence, which may reflect altered neurodevelopment of these regions.
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Sexual Dimorphisms and Prediction of Conversion in the NAPLS Psychosis Prodrome
Schizophrenia Research.
Mar, 2013 |
Pubmed ID: 23340377 Sex differences in age at onset, symptomatology, clinical course (see Walker et al., 2002) and functional impairment (Thorup et al., 2007) are well documented in psychosis. The general pattern of findings is that males manifest an earlier onset, more severe symptoms and poorer prognosis than females. Limited studies examining individuals at clinical high-risk (CHR) suggest a similar pattern of sexual dimorphism (Holtzman et al., in review; Corcoran et al., 2011). As part of the North American Prodrome Longitudinal Study (NAPLS), the current study prospectively examined sexual dimorphisms in relationships among CHR symptoms, childhood (premorbid) academic and social functioning, baseline social and role functioning, and conversion to psychosis. Subjects included 276 (113F/163M) CHR NAPLS participants (ages 12-36.8years). All measures/criteria were assessed at baseline except conversion status, assessed at 6-month intervals up to 30months. Results show sex differences in baseline social and role functioning (though not in early childhood adjustment) that predate psychosis onset, with sexually dimorphic patterns in relation to prodromal symptoms. Among male (but not female) CHRs, baseline social functioning and positive prodromal symptoms predicted conversion. These findings help elucidate early course of vulnerability for, and maximally sensitive and specific etiological and prediction models of, psychosis conversion. Findings highlight the importance of considering sexually differentiated predictors of longitudinal course and outcome, in the context of emerging risk profiles. This may optimize efforts at early identification and individually tailored preventive interventions targeting different neurobiological markers/systems and/or cognitive-behavioral approaches. We speculate a contemporary, multidimensional model of psychosis risk that posits a role of sexually dimorphic, genetically linked influences that converge with a modulating role of gonadal hormones (see Walder et al., 2012) across a temporally sensitive neurodevelopmental trajectory towards conferring risk.
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The Genomic Psychiatry Cohort: Partners in Discovery
American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics : the Official Publication of the International Society of Psychiatric Genetics.
Jun, 2013 |
Pubmed ID: 23650244 The Genomic Psychiatry Cohort (GPC) is a longitudinal resource designed to provide the necessary population-based sample for large-scale genomic studies, studies focusing on Research Domain Criteria (RDoC) and/or other alternate phenotype constructs, clinical and interventional studies, nested case-control studies, long-term disease course studies, and genomic variant-to-phenotype studies. We provide and will continue to encourage access to the GPC as an international resource. DNA and other biological samples and diagnostic data are available through the National Institute of Mental Health (NIMH) Repository. After appropriate review and approval by an advisory board, investigators are able to collaborate in, propose, and co-lead studies involving cohort participants.
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Premorbid Functional Development and Conversion to Psychosis in Clinical High-risk Youths
Development and Psychopathology.
Nov, 2013 |
Pubmed ID: 24229556 Deterioration in premorbid functioning is a common feature of schizophrenia, but sensitivity to psychosis conversion among clinical high-risk samples has not been examined. This study evaluates premorbid functioning as a predictor of psychosis conversion among a clinical high-risk sample, controlling for effects of prior developmental periods. Participants were 270 clinical high-risk individuals in the North American Prodrome Longitudinal Study-I, 78 of whom converted to psychosis over the next 2.5 years. Social, academic, and total maladjustment in childhood, early adolescence, and late adolescence were rated using the Cannon-Spoor Premorbid Adjustment Scale. Early adolescent social dysfunction significantly predicted conversion to psychosis (hazard ratio = 1.30, p = .014), independently of childhood social maladjustment and independently of severity of most baseline positive and negative prodromal symptoms. Baseline prodromal symptoms of disorganized communication, social anhedonia, suspiciousness, and diminished ideational richness mediated this association. Early adolescent social maladjustment and baseline suspiciousness together demonstrated moderate positive predictive power (59%) and high specificity (92.1%) in predicting conversion. Deterioration of academic and total functioning, although observed, did not predict conversion to psychosis. Results indicate early adolescent social dysfunction to be an important early predictor of conversion. As such, it may be a good candidate for inclusion in prediction algorithms and could represent an advantageous target for early intervention.
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Reliability of Functional Magnetic Resonance Imaging Activation During Working Memory in a Multi-site Study: Analysis from the North American Prodrome Longitudinal Study
NeuroImage.
Aug, 2014 |
Pubmed ID: 24736173 Multi-site neuroimaging studies offer an efficient means to study brain functioning in large samples of individuals with rare conditions; however, they present new challenges given that aggregating data across sites introduces additional variability into measures of interest. Assessing the reliability of brain activation across study sites and comparing statistical methods for pooling functional data are critical to ensuring the validity of aggregating data across sites. The current study used two samples of healthy individuals to assess the feasibility and reliability of aggregating multi-site functional magnetic resonance imaging (fMRI) data from a Sternberg-style verbal working memory task. Participants were recruited as part of the North American Prodrome Longitudinal Study (NAPLS), which comprises eight fMRI scanning sites across the United States and Canada. In the first study sample (n=8), one participant from each home site traveled to each of the sites and was scanned while completing the task on two consecutive days. Reliability was examined using generalizability theory. Results indicated that blood oxygen level-dependent (BOLD) signal was reproducible across sites and was highly reliable, or generalizable, across scanning sites and testing days for core working memory ROIs (generalizability ICCs=0.81 for left dorsolateral prefrontal cortex, 0.95 for left superior parietal cortex). In the second study sample (n=154), two statistical methods for aggregating fMRI data across sites for all healthy individuals recruited as control participants in the NAPLS study were compared. Control participants were scanned on one occasion at the site from which they were recruited. Results from the image-based meta-analysis (IBMA) method and mixed effects model with site covariance method both showed robust activation in expected regions (i.e. dorsolateral prefrontal cortex, anterior cingulate cortex, supplementary motor cortex, superior parietal cortex, inferior temporal cortex, cerebellum, thalamus, basal ganglia). Quantification of the similarity of group maps from these methods confirmed a very high (96%) degree of spatial overlap in results. Thus, brain activation during working memory function was reliable across the NAPLS sites and both the IBMA and mixed effects model with site covariance methods appear to be valid approaches for aggregating data across sites. These findings indicate that multi-site functional neuroimaging can offer a reliable means to increase power and generalizability of results when investigating brain function in rare populations and support the multi-site investigation of working memory function in the NAPLS study, in particular.
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Reliability of an FMRI Paradigm for Emotional Processing in a Multisite Longitudinal Study
Human Brain Mapping.
Jul, 2015 |
Pubmed ID: 25821147 Multisite neuroimaging studies can facilitate the investigation of brain-related changes in many contexts, including patient groups that are relatively rare in the general population. Though multisite studies have characterized the reliability of brain activation during working memory and motor functional magnetic resonance imaging tasks, emotion processing tasks, pertinent to many clinical populations, remain less explored. A traveling participants study was conducted with eight healthy volunteers scanned twice on consecutive days at each of the eight North American Longitudinal Prodrome Study sites. Tests derived from generalizability theory showed excellent reliability in the amygdala ( Eρ2 = 0.82), inferior frontal gyrus (IFG; Eρ2 = 0.83), anterior cingulate cortex (ACC; Eρ2 = 0.76), insula ( Eρ2 = 0.85), and fusiform gyrus ( Eρ2 = 0.91) for maximum activation and fair to excellent reliability in the amygdala ( Eρ2 = 0.44), IFG ( Eρ2 = 0.48), ACC ( Eρ2 = 0.55), insula ( Eρ2 = 0.42), and fusiform gyrus ( Eρ2 = 0.83) for mean activation across sites and test days. For the amygdala, habituation ( Eρ2 = 0.71) was more stable than mean activation. In a second investigation, data from 111 healthy individuals across sites were aggregated in a voxelwise, quantitative meta-analysis. When compared with a mixed effects model controlling for site, both approaches identified robust activation in regions consistent with expected results based on prior single-site research. Overall, regions central to emotion processing showed strong reliability in the traveling participants study and robust activation in the aggregation study. These results support the reliability of blood oxygen level-dependent signal in emotion processing areas across different sites and scanners and may inform future efforts to increase efficiency and enhance knowledge of rare conditions in the population through multisite neuroimaging paradigms.
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North American Prodrome Longitudinal Study (NAPLS 2): The Prodromal Symptoms
The Journal of Nervous and Mental Disease.
May, 2015 |
Pubmed ID: 25919383 In studies describing the long-term follow-up up of youth at clinical high risk (CHR) of psychosis, little attention has been given to details of specific prodromal symptoms. In this paper, we describe the prodromal symptoms of 764 CHR participants recruited in the multi-site North American Prodrome Longitudinal Study (NAPLS). Symptoms were rated on the Scale of Prodromal Symptoms (SOPS) at baseline and 6-, 12-, 18-, and 24-month follow-ups. Clinical outcome at the 2-year assessment was categorized as psychotic, prodromal progression, symptomatic or in remission. Most of the CHR sample (92%) met criteria for the attenuated positive symptoms syndrome (APSS). Significant improvements in SOPS symptoms were observed over time. Unusual thought content, disorganized communication, and overall ratings on disorganized symptoms differentiated those who transitioned to psychosis from the other clinical outcome groups. Suspiciousness and total positive symptoms differentiated those in remission from the other clinical outcome groups.
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Demographic Correlates of Attenuated Positive Psychotic Symptoms
Schizophrenia Research.
Aug, 2015 |
Pubmed ID: 25999040 It is now well established that the utilization of standardized clinical criteria can enhance prediction of psychosis. These criteria are primarily concerned with the presence and severity of attenuated positive symptoms. Because these symptom criteria are used to derive algorithms for designating clinical high risk (CHR) status and for maximizing prediction of psychosis risk, it is important to know whether the symptom ratings vary as a function of demographic factors that have previously been linked with symptoms in diagnosed psychotic patients. Using a sample of 356 CHR individuals from the NAPLS-II multi-site study, we examined the relation of three sex, age, and educational level, with the severity of attenuated positive symptom scores from the Scale of Prodromal Symptoms (SOPS). Demographic factors accounted for little of the variance in symptom ratings (5-6%). Older CHR individuals manifested more severe suspiciousness, and female CHR participants reported more unusual perceptual experiences than male participants. Contrary to prediction, higher educational level was associated with more severe ratings of unusual thought content, but less severe perceptual abnormalities. Overall, sex, age and education were modestly related to unusual thought content and perceptual abnormalities, only, suggesting minimal implication for designating CHR status and predicting psychosis-risk.
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Specificity of Incident Diagnostic Outcomes in Patients at Clinical High Risk for Psychosis
Schizophrenia Bulletin.
Sep, 2015 |
Pubmed ID: 26272875 It is not well established whether the incident outcomes of the clinical high-risk (CHR) syndrome for psychosis are diagnostically specific for psychosis or whether CHR patients also are at elevated risk for a variety of nonpsychotic disorders. We collected 2 samples (NAPLS-1, PREDICT) that contained CHR patients and a control group who responded to CHR recruitment efforts but did not meet CHR criteria on interview (help-seeking comparison patients [HSC]). Incident diagnostic outcomes were defined as the occurrence of a SIPS-defined psychosis or a structured interview diagnosis from 1 of 3 nonpsychotic Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) groups (anxiety, bipolar, or nonbipolar mood disorder), when no diagnosis in that group was present at baseline. Logistic regression revealed that the CHR vs HSC effect did not vary significantly across study for any emergent diagnostic outcome; data from the 2 studies were therefore combined. CHR (n = 271) vs HSC (n = 171) emergent outcomes were: psychosis 19.6% vs 1.8%, bipolar disorders 1.1% vs 1.2%, nonbipolar mood disorders 4.4% vs 5.3%, and anxiety disorders 5.2% vs 5.3%. The main effect of CHR vs HSC was statistically significant (OR = 13.8, 95% CI 4.2-45.0, df = 1, P < .001) for emergent psychosis but not for any emergent nonpsychotic disorder. Sensitivity analyses confirmed these findings. Within the CHR group emergent psychosis was significantly more likely than each nonpsychotic DSM-IV emergent disorder, and within the HSC group emergent psychosis was significantly less likely than most emergent nonpsychotic disorders. The CHR syndrome is specific as a marker for research on predictors and mechanisms of developing psychosis.
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