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1.
J Appl Psychol ; 109(3): 456-467, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37824270

RESUMO

Performance appraisal (PA) is used for various organizational purposes and is vital to human resources practices. Despite this, current estimates of PA reliability are low, leading to decades of criticism regarding the use of PA in organizational contexts. In this article, we argue that current meta-analytical interrater reliability (IRR) coefficients are underestimates and do not reflect the reliability of interest to most practitioners and researchers-the reliability of an employee's direct supervisor. To establish the reliability of direct supervisor ratings, those making PA ratings must directly supervise employee job performance instead of nonparallel rater designs (e.g., direct supervisor ratings correlated with ratings from a more senior leader). The current meta-analysis identified 22 independent samples that met this more restrictive study inclusion criterion, finding an average observed IRR of .65. We also report reliability estimates for several important contextual moderators, including whether ratings were completed in operational settings (.60) or for research purposes (.67). In sum, we argue that this study's meta-analytical IRR estimates are the best available estimates of direct supervisor reliability and should be used to guide future research and practice. (PsycInfo Database Record (c) 2024 APA, all rights reserved).


Assuntos
Avaliação de Desempenho Profissional , Desempenho Profissional , Humanos , Reprodutibilidade dos Testes
2.
J Appl Psychol ; 108(11): 1812-1833, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37326537

RESUMO

Forced-choice (FC) personality assessments have shown potential in mitigating the effects of faking. Yet despite increased attention and usage, there exist gaps in understanding the psychometric properties of FC assessments, and particularly when compared to traditional single-stimulus (SS) measures. The present study conducted a series of meta-analyses comparing the psychometric properties of FC and SS assessments after placing them on an equal playing field-by restricting to only studies that examined matched assessments of each format, and thus, avoiding the extraneous confound of using comparisons from different contexts (Sackett, 2021). Matched FC and SS assessments were compared in terms of criterion-related validity and susceptibility to faking in terms of mean shifts and validity attenuation. Additionally, the correlation between FC and SS scores was examined to help establish construct validity evidence. Results showed that matched FC and SS scores exhibit strong correlations with one another (ρ = .69), though correlations weakened when the FC measure was faked (ρ = .59) versus when both measures were taken honestly (ρ = .73). Average scores increased from honest to faked samples for both FC (d = .41) and SS scores (d = .75), though the effect was more pronounced for SS measures and with larger effects for context-desirable traits (FC d = .61, SS d = .99). Criterion-related validity was similar between matched FC and SS measures overall. However, when considering validity in faking contexts, FC scores exhibited greater validity than SS measures. Thus, although FC measures are not completely immune to faking, they exhibit meaningful benefits over SS measures in contexts of faking. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Assuntos
Enganação , Personalidade , Humanos , Psicometria , Inventário de Personalidade , Determinação da Personalidade
3.
J Appl Psychol ; 108(6): 1027-1045, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36455013

RESUMO

Researchers and practitioners are often interested in assessing employee attitudes and work perceptions. Although such perceptions are typically measured using Likert surveys or some other closed-end numerical rating format, many organizations also have access to large amounts of qualitative employee data. For example, open-ended comments from employee surveys allow workers to provide rich and contextualized perspectives about work. Unfortunately, there are practical challenges when trying to understand employee perceptions from qualitative data. Given this, the present study investigated whether natural language processing (NLP) algorithms could be developed to automatically score employee comments according to important work attitudes and perceptions. Using a large sample of employees, algorithms were developed to translate text into scores that reflect what comments were about (theme scores) and how positively targeted constructs were described (valence scores) for 28 work constructs. The resulting algorithms and scores are labeled the Text-Based Attitude and Perception Scoring (TAPS) dictionaries, which are made publicly available and were built using a mix of count-based scoring and transformer neural networks. The psychometric properties of the TAPS scores were then investigated. Results showed that theme scores differentiated responses based on their likelihood to discuss specific constructs. Additionally, valence scores exhibited strong evidence of reliability and validity, particularly, when analyzed on text responses that were more relevant to the construct of interest. This suggests that researchers and practitioners should explicitly design text prompts to elicit construct-related information if they wish to accurately assess work attitudes and perceptions via NLP. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Assuntos
Atitude , Processamento de Linguagem Natural , Humanos , Reprodutibilidade dos Testes , Inquéritos e Questionários , Psicometria
4.
Int J Sel Assess ; 30(1): 167-181, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35935096

RESUMO

This study introduces a novel, game-like method for measuring social intelligence: the Social Shapes Test. Unlike other existing video or game-based tests, the Shapes Test uses animations of abstract shapes to represent social interactions. We explore demographic differences in Shapes Test scores compared to a written situational judgment test. Gender and race/ethnicity only had meaningful effects on written SJT scores while no effects were found for Shapes Test scores. This pattern of results remained after controlling for general mental ability and English language exposure. We also found metric invariance between demographic groups for both tests. Our results demonstrate the potential for using animated shape tasks as an alternative to written SJTs when designing future game-based assessments.

5.
J Appl Psychol ; 107(10): 1678-1705, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34672651

RESUMO

Although biodata inventories have long been used to hire job applicants, there are limitations to current biodata knowledge and little in the way of contemporary biodata meta-analytic reviews. This study establishes a precise understanding of biodata validity by conducting an updated meta-analysis that differentiates biodata validity in terms of two important defining features: construct domain and scoring method (rational, hybrid, empirical). Evidence was established in terms of criterion-related validity with job performance and additional work outcomes, as well as convergent validity with common external hiring measures. In total, 180 independent samples of criterion correlations were examined, and 63 samples were analyzed containing correlations with convergent measures. Findings across the meta-analyses revealed that biodata inventories are one of the most predictive assessment methods available, but that the relationship with work outcomes differs by construct domain and scoring method. Empirically scored overall composite scales had superior criterion-related validity (ρ = .44) to rationally scored composite scales (ρ = .24). Scales developed to measure conscientiousness and leadership were generally the most predictive of the job performance of the narrow construct domains, and particularly when empirically keyed. However, when biodata scores were correlated with theoretically aligned performance ratings, rational scoring resulted in similar validity coefficients as empirical scoring. Finally, biodata scales exhibited expected patterns of correlations with external measures and were only modestly correlated with cognitive ability and five-factor model personality scores. Taken together, biodata inventories are highly predictive assessment methods and are likely to provide unique variance over other common predictors. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Confiabilidade dos Dados , Emprego , Humanos , Liderança , Personalidade , Seleção de Pessoal , Reprodutibilidade dos Testes , Desempenho Profissional
6.
J Appl Psychol ; 107(8): 1428-1439, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34582241

RESUMO

The use of personality measures to predict work-related outcomes has been of great interest over the past several decades. The present study used machine learning (ML) to examine the optimal level in the personality hierarchy to use in developing predictive algorithms. This issue was examined in a sample of incumbent police officers (N = 1,043) who completed a multifaceted personality measure and were rated on their job performance. Criterion-related validity was investigated as a function of level of operationalization in the personality hierarchy (dimensions, facets, items), scoring method (unit weighting, ordinary least-squares regression, elastic net regression), content relevance (all items vs. job-related items), and sample size (100, 200, 300, 500, 800). Results showed that empirically derived scores outperformed unit weighting across all levels of the personality hierarchy. The highest validity estimates were consistently obtained using elastic net scoring (with hyperparameter tuning resulting in solutions closer to ridge regression) at the item level, with minimal differences between ordinary least squares and elastic net for dimensions or facets with at least moderate sample sizes (N ≥ 200). An exploratory modeling approach where all item content was used did not outperform scoring when the item pool was relegated to only job-relevant personality traits. Taken together, findings suggest that personality scoring should occur at narrow operationalizations down to at least the facet level. In addition, this study demonstrated how ML can be used to not only maximize criterion-related validity but also to test long-standing theoretical problems in the organizational sciences. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Determinação da Personalidade , Transtornos da Personalidade , Humanos , Personalidade , Inventário de Personalidade , Reprodutibilidade dos Testes
7.
Sleep ; 41(7)2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29771362

RESUMO

If protein synthesis during sleep is required for sleep-dependent memory consolidation, we might expect rates of cerebral protein synthesis (rCPS) to increase during sleep in the local brain circuits that support performance on a particular task following training on that task. To measure circuit-specific brain protein synthesis during a daytime nap opportunity, we used the L-[1-(11)C]leucine positron emission tomography (PET) method with simultaneous polysomnography. We trained subjects on the visual texture discrimination task (TDT). This was followed by a nap opportunity during the PET scan, and we retested them later in the day after the scan. The TDT is considered retinotopically specific, so we hypothesized that higher rCPS in primary visual cortex would be observed in the trained hemisphere compared to the untrained hemisphere in subjects who were randomized to a sleep condition. Our results indicate that the changes in rCPS in primary visual cortex depended on whether subjects were in the wakefulness or sleep condition but were independent of the side of the visual field trained. That is, only in the subjects randomized to sleep, rCPS in the right primary visual cortex was higher than the left regardless of side trained. Other brain regions examined were not so affected. In the subjects who slept, performance on the TDT improved similarly regardless of the side trained. Results indicate a regionally selective and sleep-dependent effect that occurs with improved performance on the TDT.


Assuntos
Consolidação da Memória/fisiologia , Biossíntese de Proteínas/fisiologia , Sono/fisiologia , Córtex Visual/metabolismo , Vigília/fisiologia , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Radioisótopos de Carbono , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Polissonografia , Tomografia por Emissão de Pósitrons/métodos , Córtex Visual/diagnóstico por imagem , Percepção Visual , Adulto Jovem
8.
J Affect Disord ; 168: 243-53, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25069080

RESUMO

OBJECTIVE: The amygdala and hippocampus - two structures intimately associated with mood and cognition - have been reported to exhibit altered neural activity or volume in affective disorders. We hypothesized the amygdala and hippocampus would show altered and differential patterns of connectivity in patients with bipolar (BPs) and unipolar (UPs) disorder compared to healthy volunteers. METHOD: Thirty BPs, 34 UPs, and 66 healthy volunteers were imaged using F-18-fluorodeoxyglucose and positron emission tomography while performing an auditory continuous performance task (CPT). Normalized mean activity of the amygdala and hippocampus was correlated with the rest of the brain. RESULTS: In BPs, the amygdalae displayed exaggerated positive metabolic correlations with prefrontal and ventral striatal areas, while the hippocampus showed a paucity of normal inter-relations compared to controls. In contrast, in UPs the amygdala was significantly negatively correlated with prefrontal and anterior cingulate cortex, while the hippocampus was significantly more positively correlated to these same prefrontal areas. CONCLUSIONS: During a simple cognitive task, the functional connectivity of the amygdala and hippocampus, regions usually associated with emotion and memory regulation, was substantially different in affective illness compared to healthy controls whether or not there were baseline abnormalities in these areas. These striking differences in functional connectivity of amygdala and hippocampus should be further explored in ill and well states and using more specific emotion and cognitive evocative tasks.


Assuntos
Tonsila do Cerebelo/fisiopatologia , Transtorno Bipolar/fisiopatologia , Transtorno Depressivo Maior/fisiopatologia , Audição , Hipocampo/fisiopatologia , Estimulação Acústica , Adulto , Afeto , Tonsila do Cerebelo/patologia , Transtorno Bipolar/patologia , Transtorno Depressivo Maior/patologia , Emoções , Feminino , Fluordesoxiglucose F18 , Giro do Cíngulo/fisiopatologia , Hipocampo/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons/métodos , Córtex Pré-Frontal/fisiopatologia , Descanso , Análise e Desempenho de Tarefas
9.
Brain Stimul ; 7(1): 36-41, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23928104

RESUMO

BACKGROUND: While the efficacy of repetitive transcranial magnetic stimulation (rTMS) at 10 Hz over the left prefrontal cortex has been repeatedly demonstrated, it is not clear that the optimal parameters for the treatment of depression have been adequately elucidated. OBJECTIVES: We sought to assess the antidepressant effectiveness of high and low frequency at a higher intensity rTMS compared to sham in patients with moderately treatment resistant depression. METHOD: The authors conducted a three-week, double-blind, randomized, sham-controlled study of 24 acutely depressed patients given either active 20 Hz (n = 8) or 1 Hz (n = 8) rTMS (at 110% of motor threshold [MT]) or sham treatments (n = 8) over the left prefrontal cortex. Hamilton Depression ratings were analyzed by ANOVA. RESULTS: Patients on both frequencies showed greater improvement than on sham, which was associated with minor increases in depression. During open continuation to allow 7 weeks of active treatment in all individuals, additional improvement was observed. CONCLUSIONS: The results seen here using 110% of MT for 3 weeks were more robust than those of previous studies of 1-Hz or 20-Hz rTMS for 2 weeks (at 80% and 100% of MT). The results also raise the possibility that both high and low frequency rTMS over left prefrontal cortex (and not just low frequency over the right prefrontal cortex) exert antidepressant effects, but further work is required to assess what parameters may be most effective in general and for a given individual.


Assuntos
Depressão/terapia , Córtex Pré-Frontal/fisiopatologia , Estimulação Magnética Transcraniana/métodos , Adulto , Depressão/fisiopatologia , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
10.
J Appl Psychol ; 99(2): 282-95, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24364738

RESUMO

This research examines the relationship between the construct and criterion-related validity of assessment centers (ACs) based on how convergence of dimension ratings across AC exercises affects their ability to predict managerial performance. According to traditional multitrait-multimethod perspective, a high degree of convergence represents more reliable measurement and has the potential for better validity. In contrast, the concept of situational bandwidth suggests that behavior assessed under a dissimilar set of circumstances should result in a more comprehensive assessment of a candidate's tendencies even though ratings are less likely to show high convergence. To test these opposing viewpoints, data from 3 operational ACs were obtained along with experts' evaluations of exercise characteristics and supervisors' ratings of candidates' managerial performance. Across the 3 samples, AC ratings taken from exercises with dissimilar demands had higher estimates of criterion-related validity than ratings taken from similar exercises, even though the same dimension-different exercise correlations were substantially higher between similar exercises. Composites of ratings high in convergence did not emerge as better predictors of managerial performance, and validity particularly suffered when derived from ratings that converged as a result of exercises with similar demands. Implications for AC design are discussed.


Assuntos
Interpretação Estatística de Dados , Avaliação de Desempenho Profissional/normas , Seleção de Pessoal/normas , Psicometria/normas , Desenvolvimento de Pessoal/normas , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
11.
JAMA Psychiatry ; 70(3): 280-90, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23364679

RESUMO

CONTEXT: The need for improved treatment options for patients with major depressive disorder (MDD) is critical. Faster-acting antidepressants and biomarkers that predict clinical response will facilitate treatment. Scopolamine produces rapid antidepressant effects and thus offers the opportunity to characterize potential biomarkers of treatment response within short periods. OBJECTIVE: To determine if baseline brain activity when processing emotional information can predict treatment response to scopolamine in MDD. DESIGN: A double-blind, placebo-controlled, crossover study together with repeated functional magnetic resonance imaging, acquired as participants performed face-identity and face-emotion working memory tasks. SETTING: National Institute of Mental Health Division of Intramural Research Programs. PARTICIPANTS: Fifteen currently depressed outpatients meeting DSM-IV criteria for recurrent MDD and 21 healthy participants, between 18 and 55 years of age. MAIN OUTCOME MEASURE: The magnitude of treatment response to scopolamine (percentage of change in the Montgomery-Asberg Depression Rating Scale score between study end and baseline) was correlated with blood oxygen level-dependent (BOLD) signal associated with each working memory component (encode, maintenance, and test) for both identity and emotion tasks. Treatment response also was correlated with change in BOLD response (scopolamine vs baseline). Baseline activity was compared between healthy and MDD groups. RESULTS: Baseline BOLD response in the bilateral middle occipital cortex, selectively during the stimulus-processing components of the emotion working memory task (no correlation during the identity task), correlated with treatment response magnitude. Change in BOLD response following scopolamine administration in overlapping areas in the middle occipital cortex while performing the same task conditions also correlated with clinical response. Healthy controls showed higher activity in the same visual regions than patients with MDD during baseline. CONCLUSION: These results implicate cholinergic and visual processing dysfunction in the pathophysiology of MDD and suggest that neural response in the visual cortex, selectively to emotional stimuli, may provide a useful biomarker for identifying patients who will respond favorably to scopolamine. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00055575.


Assuntos
Antagonistas Colinérgicos/uso terapêutico , Transtorno Depressivo Maior , Escopolamina/uso terapêutico , Córtex Visual/fisiopatologia , Adulto , Estudos de Casos e Controles , Estudos Cross-Over , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Maior/fisiopatologia , Método Duplo-Cego , Emoções , Feminino , Neuroimagem Funcional , Humanos , Imageamento por Ressonância Magnética , Masculino , Memória de Curto Prazo , Resultado do Tratamento
12.
Psychiatry Res ; 196(1): 62-7, 2012 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-22349648

RESUMO

Identifying predictors of antidepressant response will facilitate the successful treatment of patients suffering from depression. Scopolamine produces robust antidepressant responses in unipolar and bipolar depression. Here we evaluate the potential for baseline self-ratings to predict treatment response to scopolamine. Fifty-one unipolar and bipolar patients participated in a double-blind, placebo-controlled crossover trial. Following a single-blind placebo session, participants randomly received P/S or S/P (P=3 placebo; S=3 scopolamine (4µg/kg) sessions). Mood-state self-ratings (Profile of Mood State (POMS) and Visual Analog Scales (VAS)) and depression severity (Montgomery-Åsberg Depression Rating Scale (MADRS)) were obtained before each infusion. Day 1 (baseline/placebo) self-ratings were used in a discriminant function analysis to identify linear combinations of individual items that predict response. The discriminant analysis significantly separated responders from non-responders in both the unipolar and bipolar diagnostic subgroups. The discriminant functions accurately classified over 85% of patients as responders/non-responders. The POMS depression subscale significantly correlated with clinical response, as did the VAS restlessness, sad, and irritated scales. These results indicate that self-report mood-ratings obtained before treatment can predict response outcome to scopolamine, and suggest that a constellation of mood-state features may be related to clinical response.


Assuntos
Afeto , Antidepressivos/uso terapêutico , Transtorno Depressivo Maior/tratamento farmacológico , Escopolamina/uso terapêutico , Adulto , Antidepressivos/administração & dosagem , Transtorno Depressivo Maior/diagnóstico , Análise Discriminante , Método Duplo-Cego , Feminino , Humanos , Infusões Intravenosas , Masculino , Valor Preditivo dos Testes , Escalas de Graduação Psiquiátrica/estatística & dados numéricos , Escopolamina/administração & dosagem , Autorrelato
13.
Psychiatry Res ; 164(1): 30-47, 2008 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-18801648

RESUMO

Unipolar and bipolar disorders have often been reported to exhibit abnormal regional brain activity in prefrontal cortex and paralimbic structures compared with healthy controls. We sought to ascertain how regions postulated to be abnormal in bipolar and unipolar disorders were functionally connected to the rest of the brain, and how this associativity differed from healthy controls. Thirty patients with bipolar disorder (BPs), 34 patients with unipolar disorder (UPs), and 66 healthy volunteers (Willis, M.W., Benson, B.E., Ketter, T.A., Kimbrell, T.A., George, M.S., Speer, A.M., Herscovitch, P., Post, R.M., 2008. Interregional cerebral metabolic associativity during a continuous performance task in healthy adults. Psychiatry Research: Neuroimaging 164 (1)) were imaged using F-18-fluorodeoxyglucose and positron emission tomography (FDG-PET) while performing an auditory continuous performance task (CPT). Five bilateral regions of interest (ROIs), namely dorsolateral prefrontal cortex (DLPFC), insula, inferior parietal cortex (INFP), thalamus and cerebellum, were correlated with normalized cerebral metabolism in the rest of the brain while covarying out Hamilton Depression Rating Scale Scores. In bipolar patients compared with controls, metabolism in the left DLPFC and INFP, and bilateral thalamus and insula had more positive and fewer negative metabolic correlations with other brain regions. In contrast, compared with controls, unipolar patients had fewer significant correlative relationships, either positive or negative. In common, bipolar and unipolar patients lacked the normal inverse relationships between the DLPFC and cerebellum, as well as relationships between the primary ROIs and other limbic regions (medial prefrontal cortex, anterior cingulate, and temporal lobes) compared with controls. Associations of DLPFC and INFP with other brain areas were different in each hemisphere in patients and controls. Bipolar patients exhibited exaggerated positive coherence of activity throughout the brain, while unipolar patients showed a paucity of normal interrelationships compared with controls. These abnormal patterns of metabolic associativity suggest marked interregional neuronal dysregulation in bipolar and unipolar illness exists beyond that of mere absolute regional differences from control levels, and provides rationale for using acute and long-term therapies that may re-establish and maintain normal associativity in these devastating illnesses.


Assuntos
Transtorno Bipolar/diagnóstico , Transtorno Bipolar/metabolismo , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/metabolismo , Córtex Pré-Frontal/metabolismo , Adulto , Transtorno Bipolar/fisiopatologia , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/metabolismo , Transtornos Cognitivos/fisiopatologia , Transtorno Depressivo/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Tomografia por Emissão de Pósitrons , Córtex Pré-Frontal/fisiopatologia
14.
Psychiatry Res ; 164(1): 16-29, 2008 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-18799294

RESUMO

One emerging hypothesis regarding psychiatric illnesses is that they arise from the dysregulation of normal circuits or neuroanatomical patterns. In order to study mood disorders within this framework, we explored normal metabolic associativity patterns in healthy volunteers as a prelude to examining the same relationships in affectively ill patients (Part II). We applied correlational analyses to regional brain activity as measured with FDG-PET during an auditory continuous performance task (CPT) in 66 healthy volunteers. This simple attention task controlled for brain activity that otherwise might vary amongst affective and cognitive states. There were highly significant positive correlations between homologous regions in the two hemispheres in thalamic, extrapyramidal, orbital frontal, medial temporal and cerebellar areas. Dorsal frontal, lateral temporal, cingulate, and especially insula, and inferior parietal areas showed less significant homologous associativity, suggesting more specific lateralized function. The medulla and bilateral thalami exhibited the most diverse interregional associations. A general pattern emerged of cortical regions covarying inversely with subcortical structures, particularly the frontal cortex with cerebellum, amygdala and thalamus. These analytical data may help to confirm known functional and neuroanatomical relationships, elucidate others as yet unreported, and serve as a basis for comparison to patients with psychiatric illness.


Assuntos
Encéfalo/metabolismo , Nível de Saúde , Rede Nervosa/fisiologia , Tomografia por Emissão de Pósitrons , Encéfalo/anatomia & histologia , Mapeamento Encefálico , Contagem de Células , Glucose/metabolismo , Humanos
15.
Psychiatry Res ; 140(2): 181-98, 2005 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-16257515

RESUMO

Cerebral metabolism (CMR for glucose or oxygen) and blood flow (CBF) have been reported to be closely correlated in healthy controls. Altered relationships between CMR and CBF have been reported in some brain disease states, but not others. This study examined relationships between global and regional CMRglu vs. CBF in controls and medication-free primary affective disorder patients. Nine bipolars, eight unipolars, and nine healthy controls had [15O]-water positron emission tomography (PET) scans at rest, and [18F]-fluorodeoxyglucose PET scans during an auditory continuous performance task. Patients had [15O]-water and FDG PET scans in tandem the same day; controls had an average of 45+/-27 days between scans. Maps of regional coupling were constructed for each subject group. In controls and bipolars, global and virtually all regional correlation coefficients for CMRglu and CBF were positive, albeit more robustly so in controls. However, correlative relationships in unipolars were qualitatively different, such that global and most regional measures of flow and metabolism were not positively related. Unipolars had significantly fewer positive regional correlation coefficients than healthy controls and bipolars. These were significantly different from controls in orbital cortex, anterior cingulate, posterior cingulate, and posterior temporal cortex, and different from bipolars in pregenual anterior cingulate. In unipolars, the degree of flow-metabolism uncoupling was inversely correlated with Hamilton depression scores, indicating the severity of uncoupling was directly related to the severity of depression. These preliminary data suggest abnormal relationships between cerebral metabolism and blood flow globally and regionally in patients with unipolar depression that warrant replication and extension to potential pathophysiological implications.


Assuntos
Transtorno Bipolar/metabolismo , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Transtorno Depressivo/metabolismo , Tomografia por Emissão de Pósitrons , Córtex Pré-Frontal/metabolismo , Adulto , Transtorno Bipolar/psicologia , Circulação Cerebrovascular/fisiologia , Transtorno Depressivo/psicologia , Feminino , Fluordesoxiglucose F18 , Giro do Cíngulo/metabolismo , Humanos , Masculino , Compostos Radiofarmacêuticos , Lobo Temporal/metabolismo
16.
Biol Psychiatry ; 54(8): 818-25, 2003 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-14550681

RESUMO

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) affects the excitability of the motor cortex and is thought to influence activity in other brain areas as well. We combined the administration of varying intensities of 1-Hz rTMS of the motor cortex with simultaneous positron emission tomography (PET) to delineate local and distant effects on brain activity. METHODS: Ten healthy subjects received 1-Hz rTMS to the optimal position over motor cortex (M1) for producing a twitch in the right hand at 80, 90, 100, 110, and 120% of the twitch threshold, while regional cerebral blood flow (rCBF) was measured using H(2)(15)O and PET. Repetitive transcranial magnetic stimulation (rTMS) was delivered in 75-pulse trains at each intensity every 10 min through a figure-eight coil. The regional relationship of stimulation intensity to normalized rCBF was assessed statistically. RESULTS: Intensity-dependent rCBF increases were produced under the M1 stimulation site in ipsilateral primary auditory cortex, contralateral cerebellum, and bilateral putamen, insula, and red nucleus. Intensity-dependent reductions in rCBF occurred in contralateral frontal and parietal cortices and bilateral anterior cingulate gyrus and occipital cortex. CONCLUSIONS: This study demonstrates that 1-Hz rTMS delivered to the primary motor cortex (M1) produces intensity-dependent increases in brain activity locally and has associated effects in distant sites with known connections to M1.


Assuntos
Córtex Motor/irrigação sanguínea , Tomografia Computadorizada de Emissão , Estimulação Magnética Transcraniana/instrumentação , Adulto , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Circulação Cerebrovascular/fisiologia , Limiar Diferencial , Feminino , Humanos , Masculino , Córtex Motor/diagnóstico por imagem , Crânio
17.
Biol Psychiatry ; 54(8): 826-32, 2003 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-14550682

RESUMO

BACKGROUND: The changes in brain activity produced by repetitive transcranial magnetic stimulation (rTMS) of the prefrontal cortex (PFC) remain unclear. We examined intensity-related changes in brain activity with positron emission tomography (PET) in normal volunteers during rTMS delivered to the left PFC. METHODS: In 10 healthy volunteers, we delivered 1-Hz rTMS at randomized intensities over left PFC with a figure-eight coil. Intensities were 80, 90, 100, 110, and 120% of the right-hand muscle twitch threshold. Regional cerebral blood flow (rCBF) scans were acquired with H(2)(15)O PET during rTMS at each intensity. RESULTS: Repetitive transcranial magnetic stimulation intensity was inversely correlated with rCBF in the stimulated and contralateral PFC, ipsilateral medial temporal lobe, both parahippocampi, and posterior middle temporal gyri. Positive correlations of rCBF with intensity occurred in ipsilateral anterior cingulate, cerebellum, contralateral insula, primary auditory cortex, and somatosensory face area. CONCLUSIONS: The intensity-related inverse relationship between 1-Hz rTMS and prefrontal activity appears opposite to that seen with rTMS over the motor cortex in a companion study. Intensity-dependent increases in rCBF were seen in a number of distant cortical and subcortical areas with PFC rTMS, suggesting activation of left anterior cingulate, claustrum, and cerebellum. The regional differences in direction of rTMS effects and the greater activation of distant structures at higher intensities suggest the potential importance of higher-intensity prefrontal rTMS for therapeutic applications in neuropsychiatric patients.


Assuntos
Periodicidade , Córtex Pré-Frontal/irrigação sanguínea , Tomografia Computadorizada de Emissão , Estimulação Magnética Transcraniana/instrumentação , Adulto , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Circulação Cerebrovascular/fisiologia , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Córtex Pré-Frontal/diagnóstico por imagem , Crânio
18.
J Affect Disord ; 77(1): 71-8, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14550937

RESUMO

BACKGROUND: Although previous studies have discussed age-related changes in the presentation of early onset bipolar illness, the developmental progression of early symptoms remains unclear. The current study sought to trace parents' retrospective report of yearly occurrence of symptoms in a sample of children with and without a diagnosis of bipolar disorder in the community. METHODS: Parents retrospectively rated the occurrence of 37 activated and withdrawn symptoms causing dysfunction for each year of their child's life (mean age 12.6 +/- 6.9). Children were divided into three groups based on parent report of diagnosis by a community clinician: bipolar (n=78); non-bipolar diagnosis (n=38); and well (no psychiatric diagnosis) (n=82). Principal components analysis was performed to understand the relationship among the symptom variables and their potential differences among the three groups as a function of age. RESULTS: Four symptom components were derived and these began to distinguish children with bipolar disorder from the other groups at different ages. Component II (irritability/dyscontrol), which included temper tantrums, poor frustration tolerance, impulsivity, increased aggression, decreased attention span, hyperactivity and irritability, began to distinguish bipolar children from the others the earliest (i.e., from ages 1 to 6). The other components (I, III, and IV) which included symptoms more typical of adult depression (I), mania (III), and psychosis (IV), distinguished the children with a bipolar diagnosis from the others much later (between ages 7 and 12). LIMITATIONS: The data were derived from retrospective reports by parents of their children's symptoms on a yearly symptom check list instrument which has not been previously utilized. Parents' ratings were not validated by an outside rater. Moreover, the children were diagnosed in the community and a formal diagnostic interview was not given. CONCLUSIONS: By parental report, the cluster of symptoms in the irritability/dyscontrol component may characterize the earliest precursors to an illness eventually associated with more classic manic and depressive components that are diagnosed and treated as bipolar disorder in the community. These retrospective survey data suggesting a longitudinal evolution of symptom clusters in childhood bipolar-like illness identify a number of areas for prospective research and validation.


Assuntos
Transtorno Bipolar/diagnóstico , Transtorno Bipolar/psicologia , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/psicologia , Humor Irritável , Pais , Autoeficácia , Inquéritos e Questionários , Adolescente , Adulto , Criança , Manual Diagnóstico e Estatístico de Transtornos Mentais , Progressão da Doença , Feminino , Humanos , Masculino , Psicologia da Criança , Características de Residência , Estudos Retrospectivos , Fatores de Tempo
19.
Ann Clin Psychiatry ; 15(2): 85-94, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12938866

RESUMO

Many findings implicating prefrontal cortical and limbic areas of the brain and endocrine systems in the neuropathology and pathophysiology of bipolar illness have greatly increased our understanding of the neurobiology of the illness. New imaging techniques such as PET, MRI, SPECT, and MRS have detailed more evidence of specific regional alterations in the brains of bipolar patients than was thought possible just 20 years ago. These methods are beginning to be used to help predict response to treatment. Examining the mechanisms of action of mood stabilizers (such as lithium, carbamazepine, and valproate) has provided clues to potential underlying neurobiological abnormalities in the illness. Recent studies of postmortem brain tissue have begun to confirm prefrontal cortical and limbic neurochemical and microstructural alterations in patients with bipolar illness compared with controls. It is postulated that it is the balance between primary pathological versus secondary adaptive alterations in gene expression in the illness and their enhancement or dampening by pharmacotherapy, that may determine the episodic course of mood fluctuations and remissions. Further examination of the pathophysiology and neurobiology of bipolar illness should lead to both more effective treatments and, potentially, secondary and even primary episode prevention.


Assuntos
Transtorno Bipolar/metabolismo , Encéfalo/metabolismo , Afeto/efeitos dos fármacos , Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/patologia , Encéfalo/patologia , Diagnóstico por Imagem/métodos , Humanos
20.
Biol Psychiatry ; 51(3): 253-60, 2002 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11839368

RESUMO

BACKGROUND: The objective of the current study was to examine possible clinical predictors of positive response to lamotrigine or gabapentin monotherapy in treatment-refractory affectively ill patients. METHODS: Forty-five patients with treatment refractory bipolar (n = 35) or unipolar (n = 10) affective disorder participated in a clinical study evaluating six weeks of treatment with lamotrigine, gabapentin, or placebo monotherapy given in a double-blind, randomized fashion with two subsequent cross-overs to the other agents. Patients received daily mood ratings and weekly cross-sectional scales. Much or very much improved on the Clinical Global Impression scale modified for bipolar illness was considered a positive response. Degree of response was correlated with a number of baseline demographic and course of illness variables in a univariate analysis and then by linear regression. RESULTS: Response rates to lamotrigine (51%) exceeded those to gabapentin (28%) and placebo (21%). A positive response to lamotrigine monotherapy was associated with a bipolar diagnosis; fewer hospitalizations; fewer prior medication trials; and male gender (of which the latter two variables survived logistic regression). For gabapentin, degree of response correlated with shorter duration of illness; younger age; and lower baseline weight (with the latter two surviving linear regression). CONCLUSIONS: In this highly treatment-refractory population, lamotrigine appeared most effective for male patients with fewer prior medication trials. Gabapentin monotherapy, although not better than placebo, appeared most effective in those with younger age and lower baseline weight. These preliminary data in a treatment refractory subgroup may help in the further definition of the range of clinical utility of these widely used anticonvulsants.


Assuntos
Aminas , Antidepressivos/uso terapêutico , Ácidos Cicloexanocarboxílicos , Transtornos do Humor/diagnóstico , Triazinas/uso terapêutico , Ácido gama-Aminobutírico , Acetatos/uso terapêutico , Adulto , Idoso , Estudos Cross-Over , Estudos Transversais , Método Duplo-Cego , Resistência a Medicamentos , Feminino , Previsões , Gabapentina , Humanos , Lamotrigina , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos
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