Browsing by Author "Pocinho, F"
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- Auto-conceito, coping e ideias de suicídioPublication . Vaz-Serra, A; Pocinho, F
- Brain activation of the defensive and appetitive survival systems in obsessive compulsive disorderPublication . Gonçalves, OF; Soares, JM; Carvalho, S; Leite, J; Ganho, A; Fernandes-Gonçalves, A; Frank, B; Pocinho, F; Relvas, J; Carracedo, A; Sampaio, ASeveral studies have shown that basic emotions are responsible for a significant enhancement of early visual processes and increased activation in visual processing brain regions. It may be possible that the cognitive uncertainty and repeated behavioral checking evident in Obsessive Compulsive Disorder (OCD) is due to the existence of abnormalities in basic survival circuits, particularly those associated with the visual processing of the physical characteristics of emotional-laden stimuli. The objective of the present study was to test if patients with OCD show evidence of altered basic survival circuits, particularly those associated with the visual processing of the physical characteristics of emotional stimuli. Fifteen patients with OCD and 12 healthy controls underwent functional magnetic resonance imaging acquisition while being exposed to emotional pictures, with different levels of arousal, intended to trigger the defensive and appetitive basic survival circuits. Overall, the present results seem to indicate dissociation in the activity of the defense and appetitive survival systems in OCD. Results suggest that the clinical group reacts to basic threat with a strong activation of the defensive system mobilizing widespread brain networks (i.e., frontal, temporal, occipital-parietal, and subcortical nucleus) and blocking the activation of the appetitive system when facing positive emotional triggers from the initial stages of visual processing (i.e., superior occipital gyrus).
- Imbalance in habitual versus goal directed neural systems during symptom provocation in obsessive-compulsive disorderPublication . Banca, P; Voon, V; Vestergaard, MD; Philipiak, G; Almeida, I; Pocinho, F; Relvas, J; Castelo-BrancoIntrusive thoughts and compulsive urges to perform stereotyped behaviours are typical symptoms of obsessive-compulsive disorder. Emerging evidence suggests a cognitive bias towards habit formation at the expense of goal-directed performance in obsessive-compulsive disorder. In this study, we test this hypothesis using a novel individualized ecologically valid symptom provocation design: a live provocation functional magnetic resonance imaging paradigm with synchronous video-recording of behavioural avoidance responses. By pairing symptom provocation with online avoidance responses on a trial-by-trial basis, we sought to investigate the neural mechanisms leading to the compulsive avoidance response. In keeping with the model of habit formation in obsessive-compulsive disorder, we hypothesized that this disorder would be associated with lower activity in regions implicated in goal-directed behaviours and higher activity in regions implicated in habitual behaviours. Fifteen patients with obsessive-compulsive disorder and 15 healthy control volunteers participated in this functional magnetic resonance imaging study. Online stimuli were individually tailored to achieve effective symptom provocation at neutral, intermediate and strong intensity levels. During the symptom provocation block, the participant could choose to reject or terminate the provoking stimuli resulting in cessation of the symptom provocation. We thus separately analysed the neural correlates of symptom provocation, the urge to avoid, rejection and relief. Strongly symptom-provoking conditions evoked a dichotomous pattern of deactivation/activation in patients, which was not observed either in control conditions or in healthy subjects: a deactivation of caudate-prefrontal circuits accompanied by hyperactivation of subthalamic nucleus/putaminal regions. This finding suggests a dissociation between regions engaged in goal-directed and habitual behaviours. The putaminal hyperactivity during patients' symptom provocation preceded subsequent deactivation during avoidance and relief events, indicating a pivotal role of putamen in regulation of behaviour and habit formation in obsessive-compulsive disorder. Effective connectivity analysis identified the ventromedial prefrontal cortex/orbitofrontal cortex as the main structure in this circuitry involved in the modulation of compulsivity in obsessive-compulsive disorder. These findings suggest an imbalance in circuitry underlying habitual and goal-directed action control, which may represent a fundamental mechanism underlying compulsivity in obsessive-compulsive disorder. Our results complement current models of symptom generation in obsessive-compulsive disorder and may enable the development of future therapeutic approaches that aim to alleviate this imbalance.
- Obsessive Compulsive Disorder as a functional interhemispheric imbalance at the thalamic levelPublication . Gonçalves, OF; Carvalho, S; Leite, J; Pocinho, F; Relvas, J; Fregni, FObsessive Compulsive Disorder (OCD) involves failures in two main inhibitory processes, namely cognitive (obsessions) and behavioral (compulsions). Recent research has supported two cortical-subcortical pathways on OCD pathogenesis: (a) the frontostriatal loop (dorsolateral-caudate-striatum-thalamus) responsible for impairments of behavioral inhibition; (b) the orbitofrontal loop (orbitofrontal, medial prefrontal and cingulate) responsible for impairments with cognitive inhibitory processes. These failures in both cognitive and motor inhibitory systems may mediate several neuropsychological deficits in these patients, namely memory, attention, planning and decision making. But are those deficits related to specific hemispheric effects, namely functional imbalance between hemispheres? In this article we hypothesize that: (1) OCD patients have an inter-hemispheric functional imbalance, probably due to inadequate filtering at the thalamic level; (2) the restoration of inter-hemispheric balance, will be correlative to symptomatic improvement.
- Perfeccionismo e perturbações do espectro obsessivo-compulsivo: resultados preliminaresPublication . Maia, BR; Pereira, AT; Soares, MJ; Bos, SC; Cabral, AS; Valente, J; Macedo, A; Pocinho, F; Azevedo, MH
- Perfectionism in obsessive-compulsive and eating disordersPublication . Maia, BR; Soares, MJ; Gomes, A; Marques, M; Pereira, AT; Cabral, AS; Valente, J; Bos, SC; Pato, ML; Pocinho, F; Azevedo, MH; Macedo, AOBJETIVO: Este estudo tem dois objetivos principais. Primeiro, avaliar as dimensões do perfeccionismo no transtorno obsessivo-compulsivo e nos transtornos alimentares em comparação com duas amostras controle: psiquiátrica (depressão/ansiedade) e não clínica. Segundo, avaliar se o perfeccionismo é um traço de personalidade especificamente relacionado com estas diferentes condições clínicas. MÉTODO: 39 pacientes com transtorno obsessivo-compulsivo, 24 com transtornos alimentares, 65 com um diagnóstico de depressão e/ou ansiedade (todos estes pacientes encontravam-se em regime de ambulatório) e 70 controles não clínicos completaram a versão portuguesa da Multidimensional Perfectionism Scale. RESULTADOS: Comparativamente à amostra não clínica, todas as amostras clínicas apresentaram níveis significativamente mais elevados na Multidimensional Perfectionism Scale total, no Perfeccionismo Auto-Orientado e no Perfeccionismo-Socialmente-Prescrito. Não houve diferenças estatisticamente significativas no Perfeccionismo-Auto-Orientado e na Multidimensional Perfectionism Scale total nas três amostras clínicas. No entanto, a amostra com transtornos alimentares apresentou níveis significativamente mais elevados de Perfeccionismo-Socialmente-Prescrito, comparativamente à transtornos alimentares e à amostra psiquiátrica (depressão/ansiedade). CONCLUSÃO: O perfeccionismo revelou estar associado a uma grande variedade de condições psicopatológicas. Contudo, as diferenças encontradas entre a amostra de transtornos alimentares, de transtorno obsessivo-compulsivo e a psiquiátrica no Perfeccionismo-Socialmente-Prescrito necessitam de investigação subsequente no sentido de clarificar a especificidade desta dimensão com os transtornos alimentares.
- Psicoterapia e Neurociências: o que muda no cérebroPublication . Pocinho, F; Madeira, N; Marques, D; Bettencourt, D; Relvas, J