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1.
Mol Psychiatry ; 26(6): 2504-2513, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33154566

RESUMEN

Patients at clinical high-risk (CHR) for psychosis show elevations in [18F]DOPA uptake, an estimate of dopamine (DA) synthesis capacity, in the striatum predictive of conversion to schizophrenia. Intrasynaptic DA levels can be inferred from imaging the change in radiotracer binding at D2 receptors due to a pharmacological challenge. Here, we used methylphenidate, a DA reuptake inhibitor, and [11C]-(+)-PHNO, to measure synaptic DA availability in CHR both in striatal and extra-striatal brain regions. Fourteen unmedicated, nonsubstance using CHR individuals and 14 matched control subjects participated in the study. Subjects underwent two [11C]-(+)-PHNO scans, one at baseline and one following administration of a single oral dose (60 mg) of methylphenidate. [11C]-(+)-PHNO BPND, the binding potential relative to the nondisplaceable compartment, was derived using the simplified reference tissue model with cerebellum as reference tissue. The percent change in BPND between scans, ΔBPND, was computed as an index of synaptic DA availability, and group comparisons were performed with a linear mixed model. An overall trend was found for greater synaptic DA availability (∆BPND) in CHR than controls (p = 0.06). This was driven entirely by ∆BPND in ventral striatum (-34 ± 14% in CHR, -20 ± 12% in HC; p = 0.023). There were no significant group differences in any other brain region. There were no significant differences in DA transmission in any striatal region between converters and nonconverters, although this finding is limited by the small sample size (N = 2). There was a strong and negative correlation between ΔBPND in VST and severity of negative symptoms at baseline in the CHR group (r = -0.66, p < 0.01). We show abnormally increased DA availability in the VST in CHR and an inverse relationship with negative symptoms. Our results suggest a potential early role for mesolimbic dopamine overactivity in CHR. Longitudinal studies are needed to ascertain the significance of the differential topography observed here with the [18F]DOPA literature.


Asunto(s)
Metilfenidato , Trastornos Psicóticos , Estriado Ventral , Dopamina , Humanos , Tomografía de Emisión de Positrones , Trastornos Psicóticos/diagnóstico por imagen , Receptores de Dopamina D3/metabolismo , Estriado Ventral/diagnóstico por imagen , Estriado Ventral/metabolismo
2.
Psychol Med ; 49(7): 1128-1137, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-29950184

RESUMEN

BACKGROUND: The authors developed a practical and clinically useful model to predict the risk of psychosis that utilizes clinical characteristics empirically demonstrated to be strong predictors of conversion to psychosis in clinical high-risk (CHR) individuals. The model is based upon the Structured Interview for Psychosis Risk Syndromes (SIPS) and accompanying clinical interview, and yields scores indicating one's risk of conversion. METHODS: Baseline data, including demographic and clinical characteristics measured by the SIPS, were obtained on 199 CHR individuals seeking evaluation in the early detection and intervention for mental disorders program at the New York State Psychiatric Institute at Columbia University Medical Center. Each patient was followed for up to 2 years or until they developed a syndromal DSM-4 disorder. A LASSO logistic fitting procedure was used to construct a model for conversion specifically to a psychotic disorder. RESULTS: At 2 years, 64 patients (32.2%) converted to a psychotic disorder. The top five variables with relatively large standardized effect sizes included SIPS subscales of visual perceptual abnormalities, dysphoric mood, unusual thought content, disorganized communication, and violent ideation. The concordance index (c-index) was 0.73, indicating a moderately strong ability to discriminate between converters and non-converters. CONCLUSIONS: The prediction model performed well in classifying converters and non-converters and revealed SIPS measures that are relatively strong predictors of conversion, comparable with the risk calculator published by NAPLS (c-index = 0.71), but requiring only a structured clinical interview. Future work will seek to externally validate the model and enhance its performance with the incorporation of relevant biomarkers.


Asunto(s)
Reglas de Decisión Clínica , Entrevista Psicológica , Trastornos Psicóticos/diagnóstico , Medición de Riesgo/estadística & datos numéricos , Adolescente , Adulto , Femenino , Humanos , Masculino , New York , Trastornos Psicóticos/psicología , Adulto Joven
3.
J Nerv Ment Dis ; 205(11): 893-895, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-29077651

RESUMEN

Metabolic health and positive symptom severity has been investigated in schizophrenia, but not in clinical high risk (CHR) patients. We hypothesized that greater body mass index (BMI) in CHR patients would be related to less positive symptoms. We examined this relationship in CHR patients being treated with 1) no psychotropic medications (n = 58), 2) an antipsychotic (n = 14), or 3) an antidepressant without an antipsychotic (n = 10). We found no relationship between BMI and positive symptoms in unmedicated CHR patients, the majority of whom had a narrow BMI range between 20 and 30. However, in the smaller sample of CHR patients taking an antidepressant or antipsychotic, BMI was negatively correlated with positive symptoms. Although potentially underpowered, these preliminary findings provide initial steps in elucidating the relationships between metabolic health, neurochemistry, and symptom severity in CHR patients.


Asunto(s)
Índice de Masa Corporal , Trastornos Psicóticos/psicología , Adolescente , Adulto , Antidepresivos/uso terapéutico , Antipsicóticos/uso terapéutico , Femenino , Humanos , Masculino , Escalas de Valoración Psiquiátrica , Trastornos Psicóticos/tratamiento farmacológico , Trastornos Psicóticos/etiología , Factores de Riesgo , Índice de Severidad de la Enfermedad , Adulto Joven
4.
Schizophrenia (Heidelb) ; 10(1): 54, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38773120

RESUMEN

The prospective study of youths at clinical high risk (CHR) for psychosis, including neuroimaging, can identify neural signatures predictive of psychosis outcomes using algorithms that integrate complex information. Here, to identify risk and psychosis conversion, we implemented multiple kernel learning (MKL), a multimodal machine learning approach allowing patterns from each modality to inform each other. Baseline multimodal scans (n = 74, 11 converters) included structural, resting-state functional imaging, and diffusion-weighted data. Multimodal MKL outperformed unimodal models (AUC = 0.73 vs. 0.66 in predicting conversion). Moreover, patterns learned by MKL were robust to training set variations, suggesting it can identify cross-modality redundancies and synergies to stabilize the predictive pattern. We identified many predictors consistent with the literature, including frontal cortices, cingulate, thalamus, and striatum. This highlights the advantage of methods that leverage the complex pathophysiology of psychosis.

5.
JAMA Psychiatry ; 81(1): 77-88, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37819650

RESUMEN

Importance: The lack of robust neuroanatomical markers of psychosis risk has been traditionally attributed to heterogeneity. A complementary hypothesis is that variation in neuroanatomical measures in individuals at psychosis risk may be nested within the range observed in healthy individuals. Objective: To quantify deviations from the normative range of neuroanatomical variation in individuals at clinical high risk for psychosis (CHR-P) and evaluate their overlap with healthy variation and their association with positive symptoms, cognition, and conversion to a psychotic disorder. Design, Setting, and Participants: This case-control study used clinical-, IQ-, and neuroimaging software (FreeSurfer)-derived regional measures of cortical thickness (CT), cortical surface area (SA), and subcortical volume (SV) from 1340 individuals with CHR-P and 1237 healthy individuals pooled from 29 international sites participating in the Enhancing Neuroimaging Genetics Through Meta-analysis (ENIGMA) Clinical High Risk for Psychosis Working Group. Healthy individuals and individuals with CHR-P were matched on age and sex within each recruitment site. Data were analyzed between September 1, 2021, and November 30, 2022. Main Outcomes and Measures: For each regional morphometric measure, deviation scores were computed as z scores indexing the degree of deviation from their normative means from a healthy reference population. Average deviation scores (ADS) were also calculated for regional CT, SA, and SV measures and globally across all measures. Regression analyses quantified the association of deviation scores with clinical severity and cognition, and 2-proportion z tests identified case-control differences in the proportion of individuals with infranormal (z < -1.96) or supranormal (z > 1.96) scores. Results: Among 1340 individuals with CHR-P, 709 (52.91%) were male, and the mean (SD) age was 20.75 (4.74) years. Among 1237 healthy individuals, 684 (55.30%) were male, and the mean (SD) age was 22.32 (4.95) years. Individuals with CHR-P and healthy individuals overlapped in the distributions of the observed values, regional z scores, and all ADS values. For any given region, the proportion of individuals with CHR-P who had infranormal or supranormal values was low (up to 153 individuals [<11.42%]) and similar to that of healthy individuals (<115 individuals [<9.30%]). Individuals with CHR-P who converted to a psychotic disorder had a higher percentage of infranormal values in temporal regions compared with those who did not convert (7.01% vs 1.38%) and healthy individuals (5.10% vs 0.89%). In the CHR-P group, only the ADS SA was associated with positive symptoms (ß = -0.08; 95% CI, -0.13 to -0.02; P = .02 for false discovery rate) and IQ (ß = 0.09; 95% CI, 0.02-0.15; P = .02 for false discovery rate). Conclusions and Relevance: In this case-control study, findings suggest that macroscale neuromorphometric measures may not provide an adequate explanation of psychosis risk.


Asunto(s)
Trastornos Psicóticos , Humanos , Masculino , Adulto Joven , Adulto , Femenino , Estudios de Casos y Controles , Trastornos Psicóticos/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Neuroimagen , Cognición , Síntomas Prodrómicos
6.
Front Cell Neurosci ; 17: 1126577, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36909281

RESUMEN

Background: Working memory deficits are thought to be a primary disturbance in schizophrenia. We aimed to identify differences in morphology of the hippocampus and amygdala in patients with schizophrenia compared with healthy controls (HCs), and in patients who were either neuropsychologically near normal (NPNN) or neuropsychologically impaired (NPI). Morphological disturbances in the same subfields of the hippocampus and amygdala, but of greater magnitude in those with NPI, would strengthen evidence for the centrality of these limbic regions and working memory deficits in the pathogenesis of schizophrenia. Methods: We acquired anatomical MRIs in 69 patients with schizophrenia (18 NPNN, 46 NPI) and 63 age-matched HC participants. We compared groups in hippocampus and amygdala surface morphologies and correlated morphological measures with clinical symptoms and working memory scores. Results: Schizophrenia was associated with inward deformations of the head and tail of the hippocampus, protrusion of the hippocampal body, and widespread inward deformations of the amygdala. In the same regions where we detected the effects of schizophrenia, morphological measures correlated positively with the severity of symptoms and inversely with working memory performance. Patients with NPI displayed a similar pattern of anatomical abnormality compared to patients with NPNN. Conclusion: Our findings indicate that anatomical abnormalities of the hippocampus relate to working memory performance and clinical symptoms in persons with schizophrenia. Moreover, NPNN and NPI patients may lie on a continuum of severity, both in terms of working memory abilities and altered brain structure, with NPI patients being more severe than NPNN patients in both domains.

7.
J Pers Disord ; 37(1): 36-48, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36723422

RESUMEN

In Kernerg's Object Relations Theory model of personality pathology, splitting, the mutual polarization of aspects of experience, is thought to result in a failure of identity integration. The authors sought to identify a clinician-independent, automated measure of splitting by examining 54 subjects' natural speech. Splitting in these individuals, recruited from the community, was investigated and evaluated with a shortened version of the Structured Interview of Personality Organization (STIPO-R). A type of automated sentiment textual analysis called VADER was applied to transcripts from the section of the STIPO-R that probes identity integration. Higher variability in speech valence, more negative minimum valence, and more frequent shifts in valence polarity were associated with more severe identity disturbance. The authors concluded that the degree of splitting elicited during the description of self and others is related to the degree of identity disturbance, and to the degree of negativity and instability of these descriptions of self and others.


Asunto(s)
Trastornos de la Personalidad , Análisis de Sentimientos , Humanos , Personalidad , Determinación de la Personalidad
8.
bioRxiv ; 2023 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-36711551

RESUMEN

Importance: The lack of robust neuroanatomical markers of psychosis risk has been traditionally attributed to heterogeneity. A complementary hypothesis is that variation in neuroanatomical measures in the majority of individuals at psychosis risk may be nested within the range observed in healthy individuals. Objective: To quantify deviations from the normative range of neuroanatomical variation in individuals at clinical high-risk for psychosis (CHR-P) and evaluate their overlap with healthy variation and their association with positive symptoms, cognition, and conversion to a psychotic disorder. Design Setting and Participants: Clinical, IQ and FreeSurfer-derived regional measures of cortical thickness (CT), cortical surface area (SA), and subcortical volume (SV) from 1,340 CHR-P individuals [47.09% female; mean age: 20.75 (4.74) years] and 1,237 healthy individuals [44.70% female; mean age: 22.32 (4.95) years] from 29 international sites participating in the ENIGMA Clinical High Risk for Psychosis Working Group. Main Outcomes and Measures: For each regional morphometric measure, z-scores were computed that index the degree of deviation from the normative means of that measure in a healthy reference population (N=37,407). Average deviation scores (ADS) for CT, SA, SV, and globally across all measures (G) were generated by averaging the respective regional z-scores. Regression analyses were used to quantify the association of deviation scores with clinical severity and cognition and two-proportion z-tests to identify case-control differences in the proportion of individuals with infranormal (z<-1.96) or supranormal (z>1.96) scores. Results: CHR-P and healthy individuals overlapped in the distributions of the observed values, regional z-scores, and all ADS vales. The proportion of CHR-P individuals with infranormal or supranormal values in any metric was low (<12%) and similar to that of healthy individuals. CHR-P individuals who converted to psychosis compared to those who did not convert had a higher percentage of infranormal values in temporal regions (5-7% vs 0.9-1.4%). In the CHR-P group, only the ADSSA showed significant but weak associations (|ß|<0.09; PFDR<0.05) with positive symptoms and IQ. Conclusions and Relevance: The study findings challenge the usefulness of macroscale neuromorphometric measures as diagnostic biomarkers of psychosis risk and suggest that such measures do not provide an adequate explanation for psychosis risk.

9.
Transl Psychiatry ; 12(1): 297, 2022 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-35882855

RESUMEN

Individuals at Clinical High Risk for Psychosis (CHR-P) demonstrate heterogeneity in clinical profiles and outcome features. However, the extent of neuroanatomical heterogeneity in the CHR-P state is largely undetermined. We aimed to quantify the neuroanatomical heterogeneity in structural magnetic resonance imaging measures of cortical surface area (SA), cortical thickness (CT), subcortical volume (SV), and intracranial volume (ICV) in CHR-P individuals compared with healthy controls (HC), and in relation to subsequent transition to a first episode of psychosis. The ENIGMA CHR-P consortium applied a harmonised analysis to neuroimaging data across 29 international sites, including 1579 CHR-P individuals and 1243 HC, offering the largest pooled CHR-P neuroimaging dataset to date. Regional heterogeneity was indexed with the Variability Ratio (VR) and Coefficient of Variation (CV) ratio applied at the group level. Personalised estimates of heterogeneity of SA, CT and SV brain profiles were indexed with the novel Person-Based Similarity Index (PBSI), with two complementary applications. First, to assess the extent of within-diagnosis similarity or divergence of neuroanatomical profiles between individuals. Second, using a normative modelling approach, to assess the 'normativeness' of neuroanatomical profiles in individuals at CHR-P. CHR-P individuals demonstrated no greater regional heterogeneity after applying FDR corrections. However, PBSI scores indicated significantly greater neuroanatomical divergence in global SA, CT and SV profiles in CHR-P individuals compared with HC. Normative PBSI analysis identified 11 CHR-P individuals (0.70%) with marked deviation (>1.5 SD) in SA, 118 (7.47%) in CT and 161 (10.20%) in SV. Psychosis transition was not significantly associated with any measure of heterogeneity. Overall, our examination of neuroanatomical heterogeneity within the CHR-P state indicated greater divergence in neuroanatomical profiles at an individual level, irrespective of psychosis conversion. Further large-scale investigations are required of those who demonstrate marked deviation.


Asunto(s)
Trastornos Psicóticos , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Humanos , Imagen por Resonancia Magnética , Trastornos Psicóticos/complicaciones
10.
JAMA Psychiatry ; 78(7): 753-766, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-33950164

RESUMEN

Importance: The ENIGMA clinical high risk (CHR) for psychosis initiative, the largest pooled neuroimaging sample of individuals at CHR to date, aims to discover robust neurobiological markers of psychosis risk. Objective: To investigate baseline structural neuroimaging differences between individuals at CHR and healthy controls as well as between participants at CHR who later developed a psychotic disorder (CHR-PS+) and those who did not (CHR-PS-). Design, Setting, and Participants: In this case-control study, baseline T1-weighted magnetic resonance imaging (MRI) data were pooled from 31 international sites participating in the ENIGMA Clinical High Risk for Psychosis Working Group. CHR status was assessed using the Comprehensive Assessment of At-Risk Mental States or Structured Interview for Prodromal Syndromes. MRI scans were processed using harmonized protocols and analyzed within a mega-analysis and meta-analysis framework from January to October 2020. Main Outcomes and Measures: Measures of regional cortical thickness (CT), surface area, and subcortical volumes were extracted from T1-weighted MRI scans. Independent variables were group (CHR group vs control group) and conversion status (CHR-PS+ group vs CHR-PS- group vs control group). Results: Of the 3169 included participants, 1428 (45.1%) were female, and the mean (SD; range) age was 21.1 (4.9; 9.5-39.9) years. This study included 1792 individuals at CHR and 1377 healthy controls. Using longitudinal clinical information, 253 in the CHR-PS+ group, 1234 in the CHR-PS- group, and 305 at CHR without follow-up data were identified. Compared with healthy controls, individuals at CHR exhibited widespread lower CT measures (mean [range] Cohen d = -0.13 [-0.17 to -0.09]), but not surface area or subcortical volume. Lower CT measures in the fusiform, superior temporal, and paracentral regions were associated with psychosis conversion (mean Cohen d = -0.22; 95% CI, -0.35 to 0.10). Among healthy controls, compared with those in the CHR-PS+ group, age showed a stronger negative association with left fusiform CT measures (F = 9.8; P < .001; q < .001) and left paracentral CT measures (F = 5.9; P = .005; q = .02). Effect sizes representing lower CT associated with psychosis conversion resembled patterns of CT differences observed in ENIGMA studies of schizophrenia (ρ = 0.35; 95% CI, 0.12 to 0.55; P = .004) and individuals with 22q11.2 microdeletion syndrome and a psychotic disorder diagnosis (ρ = 0.43; 95% CI, 0.20 to 0.61; P = .001). Conclusions and Relevance: This study provides evidence for widespread subtle, lower CT measures in individuals at CHR. The pattern of CT measure differences in those in the CHR-PS+ group was similar to those reported in other large-scale investigations of psychosis. Additionally, a subset of these regions displayed abnormal age associations. Widespread disruptions in CT coupled with abnormal age associations in those at CHR may point to disruptions in postnatal brain developmental processes.


Asunto(s)
Corteza Cerebral/patología , Susceptibilidad a Enfermedades , Neuroimagen , Trastornos Psicóticos/patología , Adolescente , Adulto , Factores de Edad , Estudios de Casos y Controles , Corteza Cerebral/diagnóstico por imagen , Niño , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Masculino , Síntomas Prodrómicos , Trastornos Psicóticos/diagnóstico por imagen , Riesgo , Adulto Joven
11.
Hum Brain Mapp ; 30(3): 883-95, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18344175

RESUMEN

OBJECTIVE: We aimed to study the neural processing of emotion-denoting words based on a circumplex model of affect, which posits that all emotions can be described as a linear combination of two neurophysiological dimensions, valence and arousal. Based on the circumplex model, we predicted a linear relationship between neural activity and incremental changes in these two affective dimensions. METHODS: Using functional magnetic resonance imaging, we assessed in 10 subjects the correlations of BOLD (blood oxygen level dependent) signal with ratings of valence and arousal during the presentation of emotion-denoting words. RESULTS: Valence ratings correlated positively with neural activity in the left insular cortex and inversely with neural activity in the right dorsolateral prefrontal and precuneus cortices. The absolute value of valence ratings (reflecting the positive and negative extremes of valence) correlated positively with neural activity in the left dorsolateral and medial prefrontal cortex (PFC), dorsal anterior cingulate cortex, posterior cingulate cortex, and right dorsal PFC, and inversely with neural activity in the left medial temporal cortex and right amygdala. Arousal ratings and neural activity correlated positively in the left parahippocampus and dorsal anterior cingulate cortex, and inversely in the left dorsolateral PFC and dorsal cerebellum. CONCLUSION: We found evidence for two neural networks subserving the affective dimensions of valence and arousal. These findings clarify inconsistencies from prior imaging studies of affect by suggesting that two underlying neurophysiological systems, valence and arousal, may subserve the processing of affective stimuli, consistent with the circumplex model of affect.


Asunto(s)
Mapeo Encefálico , Encéfalo/fisiología , Emociones/fisiología , Estimulación Acústica , Adulto , Nivel de Alerta/fisiología , Percepción Auditiva/fisiología , Femenino , Humanos , Interpretación de Imagen Asistida por Computador , Imagen por Resonancia Magnética , Masculino
12.
J Psychiatr Res ; 114: 88-92, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31054454

RESUMEN

The Attenuated Psychosis Syndrome (APS), proposed as a condition warranting further study in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), is a controversial diagnostic construct originally developed to identify individuals at clinical high-risk for psychosis. The relationship of APS and Schizotypal Personality Disorder (SPD) remains unclear with respect to their potential co-occurrence and the effect of SPD on risk for conversion to threshold psychosis. We examined the prevalence and effect on conversion of SPD in a cohort of 218 individuals whose symptoms met APS criteria. Results indicated that SPD was highly prevalent (68%), and that SPD did not influence risk for conversion. Rather, total positive symptom burden measured by the Structured Interview for Psychosis-Risk Syndromes (SIPS; OR 1.12, p = 0.02) emerged as the strongest predictor of conversion. These data suggest that when encountering a patient whose presentation meets SPD criteria, the clinician should assess whether APS criteria are also met and, for 1-2 years, carefully monitor positive symptoms for possible conversion to threshold psychosis.


Asunto(s)
Trastornos Psicóticos/psicología , Trastorno de la Personalidad Esquizotípica/psicología , Adolescente , Adulto , Femenino , Humanos , Entrevista Psicológica , Masculino , Trastornos Psicóticos/etiología , Factores de Riesgo , Trastorno de la Personalidad Esquizotípica/complicaciones , Síndrome , Adulto Joven
13.
Hum Brain Mapp ; 29(11): 1302-12, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17935179

RESUMEN

Previous studies have investigated patterns of volumetric covariance (i.e. intercorrelation) among brain regions. Methodological issues, however, have limited the validity and generalizability of findings from these prior studies. Additionally, patterns of volumetric covariance have often been assumed to reflect the presence of structural networks, but this assumption has never been tested formally. We identified patterns of volumetric covariance, correlated these patterns with behavioral measures, and tested the hypothesis that the observed patterns of covariance reflect the presence of underlying networks. Specifically, we performed factor analysis on regional brain volumes of 99 healthy children and adults, and we correlated factor scores with scores on the Stroop Word-Color Interference Test. We identified four latent volumetric systems in each hemisphere: dorsal cortical, limbic, posterior, and basal ganglia. The positive correlation of the right posterior system with Stroop scores suggested that larger latent volumes are detrimental to inhibitory control. We also applied Structural Equation Modeling (SEM) to our dataset (n = 107) to test whether a model based on the anatomical pathways within cortico-striatal-thalamic-cortical (CSTC) circuits accounts for the covariances observed in our sample. The degree to which SEM predicted volumetric covariance in the CSTC circuit depended on whether we controlled for age and whole brain volume in the analyses. Removing the effects of age worsened the fit of the model, pointing to a possible developmental component in establishing connections within CSTC circuits. These modeling techniques may prove useful in the future for the study of structural networks in disease populations.


Asunto(s)
Mapeo Encefálico , Encéfalo/anatomía & histología , Vías Nerviosas/anatomía & histología , Adolescente , Adulto , Niño , Análisis Factorial , Femenino , Humanos , Interpretación de Imagen Asistida por Computador , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas
14.
Neuropsychologia ; 46(8): 2129-39, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18440572

RESUMEN

Increasing evidence supports the existence of distinct neural systems that subserve two dimensions of affect--arousal and valence. Ten adult participants underwent functional magnetic resonance imaging during which they were presented a range of standardized faces and then asked, during the scan, to rate the emotional expressions of the faces along the dimensions of arousal and valence. Lower ratings of arousal accompanied greater activity in the amygdala complex, cerebellum, dorsal pons, and right medial prefrontal cortex (mPFC). More negative ratings of valence accompanied greater activity in the dorsal anterior cingulate (dACC) and parietal cortices. Extreme ratings of valence (highly positive and highly negative ratings) accompanied greater activity in the temporal cortex and fusiform gyrus. Building on an empirical literature which suggests that the amygdala serves as a salience and ambiguity detector, we interpret our findings as showing that a face rated as having low arousal is more ambiguous and a face rated as having extreme valence is more personally salient. This explains how both low arousal and extreme valence lead to greater activation of an ambiguity/salience system subserved by the amygdala, cerebellum, and dorsal pons. In addition, the right medial prefrontal cortex appears to down-regulate individual ratings of arousal, whereas the fusiform and related temporal cortices seem to up-regulate individual assessments of extreme valence when individual ratings are studied relative to group reference ratings for each stimulus. The simultaneous assessment of the effects of arousal and valence proved essential for the identification of neural systems contributing to the processing of emotional faces.


Asunto(s)
Afecto/fisiología , Nivel de Alerta/fisiología , Mapeo Encefálico , Encéfalo/fisiología , Cognición/fisiología , Expresión Facial , Adulto , Encéfalo/anatomía & histología , Encéfalo/irrigación sanguínea , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética , Masculino , Oxígeno/sangre , Reconocimiento Visual de Modelos/fisiología , Estimulación Luminosa/métodos , Valores de Referencia , Estadística como Asunto
15.
Schizophr Res ; 106(2-3): 286-93, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18809298

RESUMEN

BACKGROUND: Cannabis use is reported to increase the risk for psychosis, but no prospective study has longitudinally examined drug use and symptoms concurrently in clinical high risk cases. METHOD: We prospectively followed for up to 2 years 32 cases who met research criteria for prodromal psychosis to examine the relationship between substance use and clinical measures. RESULTS: Cases with a baseline history of cannabis use (41%) were older, but did not differ in clinical measures. Longitudinal assessments showed these cases had significantly more perceptual disturbances and worse functioning during epochs of increased cannabis use that were unexplained by concurrent use of other drugs or medications. CONCLUSIONS: These data demonstrate that cannabis use may be a risk factor for the exacerbation of subthreshold psychotic symptoms, specifically perceptual disturbances, in high risk cases.


Asunto(s)
Abuso de Marihuana/epidemiología , Trastornos Psicóticos/diagnóstico , Adulto , Trastornos de Ansiedad/diagnóstico , Trastornos de Ansiedad/epidemiología , Comorbilidad , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Femenino , Humanos , Estudios Longitudinales , Masculino , Abuso de Marihuana/diagnóstico , Abuso de Marihuana/psicología , Trastornos de la Percepción/diagnóstico , Trastornos de la Percepción/epidemiología , Trastornos de la Percepción/psicología , Estudios Prospectivos , Escalas de Valoración Psiquiátrica , Trastornos Psicóticos/epidemiología , Trastornos Psicóticos/psicología , Factores de Riesgo , Esquizofrenia/diagnóstico , Esquizofrenia/epidemiología , Índice de Severidad de la Enfermedad
16.
Artículo en Inglés | MEDLINE | ID: mdl-29202110

RESUMEN

BACKGROUND: Schizophrenia, a neurodevelopmental disorder, involves abnormalities in functional connectivity (FC) across distributed neural networks, which are thought to antedate the emergence of psychosis. In a cohort of adolescents and young adults at clinical high risk (CHR) for psychosis, we applied data-driven approaches to resting-state fMRI data so as to systematically characterize FC abnormalities during this period and determine whether these abnormalities are associated with psychosis risk and severity of psychotic symptoms. METHODS: Fifty-one CHR participants and 47 matched healthy controls (HCs) were included in our analyses. Twelve of these CHR participants developed psychosis within 3.9 years. We estimated one multivariate measure of FC and studied its relationship to CHR status, conversion to psychosis and positive symptom severity. RESULTS: Multivariate analyses revealed between-group differences in whole-brain connectivity patterns of bilateral temporal areas, mostly affecting their functional connections to the thalamus. Further, more severe positive symptoms were associated with greater connectivity abnormalities in the anterior cingulate and frontal cortex. CONCLUSIONS: Our study demonstrates that the well-established FC abnormalities of the thalamus and temporal areas observed in schizophrenia are also present in the CHR period, with aberrant connectivity of the temporal cortex most associated with psychosis risk.

17.
Psychiatry Res ; 249: 240-243, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28126579

RESUMEN

There has been recent interest in understanding the role that sleep disturbance plays in patients at Clinical High Risk for psychosis (CHR). We assessed sleep disturbance in 194 CHR patients and 66 healthy control subjects and their relationship to symptoms (positive, negative and general functioning). Patients experienced significantly more sleep disturbance than healthy control subjects and their sleep disturbance was related to greater positive and negative symptoms and worse overall functioning. Targeting sleep disturbance in CHR individuals may provide alternative means of treating the CHR syndrome.


Asunto(s)
Síntomas Prodrómicos , Trastornos Psicóticos/diagnóstico , Trastornos del Sueño-Vigilia/diagnóstico , Adolescente , Adulto , Femenino , Humanos , Masculino , Riesgo , Adulto Joven
18.
Artículo en Inglés | MEDLINE | ID: mdl-16964315

RESUMEN

BACKGROUND: Human immunodeficiency virus (HIV)-infected individuals are at increased risk of developing depression. Depressive syndromes in these patients pose a challenge both diagnostically and therapeutically. These syndromes reflect both the presence of preexisting mood disorders and the development of depressive syndromes subsequent to HIV infection. DATA SOURCES: A search of the literature to 2005 was performed using the PubMed and Ovid search engines. English- and Portuguese-language articles were identified using the following keywords: HIV or AIDS and depression, mental illness, suicide, fatigue, psychiatry, and drug interactions. Additional references were identified through bibliography reviews of relevant articles. DATA SYNTHESIS: The clinical presentation and differential diagnosis of depressive symptoms in HIV illness and the role of HIV in the development of these conditions are reviewed. Management issues including suicide assessment and treatment options are then discussed, and potentially important pharmacokinetic interactions are reviewed. CONCLUSIONS: Individuals with HIV show higher rates of depression. This phenomenon may be due to a preexisting psychiatric disorder or to the HIV infection. Untreated depression symptoms may lead to non-compliance with drug regimens or increased high-risk behaviors. Given the adverse sequelae of untreated depressions in HIV illness, identification and management of depression are integral components of comprehensive HIV care.

19.
Neuropsychopharmacology ; 41(5): 1241-50, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26354046

RESUMEN

Cognitive control, a set of functions that develop throughout adolescence, is important in the pathogenesis of psychotic disorders. Whether cognitive control has a role in conferring vulnerability for the development of psychotic illness is still unknown. The aim of this study was to investigate the neural systems supporting cognitive control in individuals deemed to be potentially prodromal for psychotic illness. We recruited 56 participants at clinical high-risk (CHR) for psychosis based on the Structured Interview for Psychosis-Risk Syndromes (SIPS) and 49 healthy controls. Twelve of the CHR participants eventually developed psychosis. We compared functional magnetic resonance imaging (fMRI) BOLD signal during the performance of the Simon task. We tested for differences between CHR individuals and controls in conflict-related functional activity. In the CHR group when compared with controls, we detected smaller conflict-related activations in several cortical areas, including the Dorsolateral Prefrontal Cortex (DLPFC). Furthermore, conflict-related activations in the DLPFC of those CHR individuals who ultimately developed psychosis (CHR converters) were smaller than in non-converters (CHR non-converters). Higher levels of conflict-related activation were associated with better social and role outcome. Risk for psychosis was associated at the neural level with reduced conflict-related brain activity. This neural phenotype appears correlated within the DLPFC with the development of psychosis and with functional outcome.


Asunto(s)
Encéfalo/fisiopatología , Cognición/fisiología , Conflicto Psicológico , Función Ejecutiva/fisiología , Trastornos Psicóticos/fisiopatología , Trastornos Psicóticos/psicología , Adulto , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Neuroimagen , Pruebas Neuropsicológicas , Corteza Prefrontal/fisiopatología , Tiempo de Reacción , Factores de Riesgo , Adulto Joven
20.
J Autism Dev Disord ; 44(6): 1332-46, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24234677

RESUMEN

The affective circumplex model holds that emotions can be described as linear combinations of two underlying, independent neurophysiological systems (arousal, valence). Given research suggesting individuals with autism spectrum disorders (ASD) have difficulty processing emotions, we used the circumplex model to compare how individuals with ASD and typically-developing (TD) individuals respond to facial emotions. Participants (51 ASD, 80 TD) rated facial expressions along arousal and valence dimensions; we fitted closed, smooth, 2-dimensional curves to their ratings to examine overall circumplex contours. We modeled individual and group influences on parameters describing curve contours to identify differences in dimensional effects across groups. Significant main effects of diagnosis indicated the ASD-group's ratings were constricted for the entire circumplex, suggesting range constriction across all emotions. Findings did not change when covarying for overall intelligence.


Asunto(s)
Nivel de Alerta , Trastornos Generalizados del Desarrollo Infantil/psicología , Expresión Facial , Adolescente , Adulto , Afecto , Estudios de Casos y Controles , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Psicológicos , Adulto Joven
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