157 research outputs found
Mechanisms of change in negative thinking and urinary monoamines in depressed patients during acute treatment with group cognitive behavior therapy and antidepressant medication
No full textThis naturalistic study investigated the mechanisms of change in measures of negative thinking and in 24-h urinary metabolites of noradrenaline (norepinephrine), dopamine and serotonin in a sample of 43 depressed hospital patients attending an eight-session group cognitive behavior therapy program. Most participants (91%) were taking antidepressant medication throughout the therapy period according to their treating Psychiatrists' prescriptions. The sample was divided into outcome categories (19 Responders and 24 Non-responders) on the basis of a clinically reliable change index [Jacobson, N.S., & Truax, P., 1991. Clinical significance: a statistical approach to defining meaningful change in psychotherapy research. Journal of Consulting and Clinical Psychology, 59, 12–19.] applied to the Beck Depression Inventory scores at the end of the therapy. Results of repeated measures analysis of variance [ANOVA] analyses of variance indicated that all measures of negative thinking improved significantly during therapy, and significantly more so in the Responders as expected. The treatment had a significant impact on urinary adrenaline and metadrenaline excretion however, these changes occurred in both Responders and Non-responders. Acute treatment did not significantly influence the six other monoamine metabolites. In summary, changes in urinary monoamine levels during combined treatment for depression were not associated with self-reported changes in mood symptoms
The Buchsbaum property of symbolic powers of Stanley–Reisner ideals of dimension 1
No full textAbstractLet S be a polynomial ring and I be the Stanley–Reisner ideal of a simplicial complex Δ. The purpose of this paper is investigating the Buchsbaum property of S/I(r) when Δ is pure dimension 1. We shall characterize the Buchsbaumness of S/I(r) in terms of the graphical property of Δ. That is closely related to the characterization of the Cohen–Macaulayness of S/I(r) due to the first author and N.V. Trung
Structural development of the basal ganglia in attention deficit hyperactivity disorder: A diffusion tensor imaging study
No full textOne of the most consistently reported brain regions of structural and functional difference in attention deficit hyperactivity disorder (ADHD) is the basal ganglia, particularly the caudate nucleus. Examining the structural organization of the basal ganglia in ADHD is important because it is the center of wider fronto-striatal networks, reported to be dysfunctional in ADHD. Fifteen right-handed 8- to 18-year-old males with ADHD-combined type and 15 right-handed, age- and performance IQ-matched healthy males underwent diffusion tensor imaging. Caudate, putamen and thalamus were manually identified as regions of interest (ROIs) and tested for differences in fractional anisotropy and mean diffusivity. Measures of fractional anisotropy (FA) showed the expected increase with age within the whole-brain volume and within putamen and thalamus ROIs for both ADHD and control groups. In the caudate nucleus, however, developmental changes in FA with age were significantly different between ADHD and control groups. This study shows that the developmental trajectory of micro-structural organization within the caudate nucleus is different in children with ADHD compared with controls over ages 8-18 years. We suggest that the difference in developmental trajectories arises predominantly during mid-late adolescence and may reflect a developmental delay that begins to normalise over this critical late adolescent age. (C) 2008 Elsevier Ireland Ltd. All rights reserved
Corpus callosum size and shape in first-episode affective and schizophrenia-spectrum psychosis
No full textReductions in the size of the anterior callosum have been described for both first-episode and established schizophrenia and bipolar affective disorder, but never in individuals with psychotic bipolar disorder. We recruited 110 first-episode psychosis subjects (74 schizophrenia spectrum and 36 affective psychosis) and 36 age- and gender-matched controls. The callosum was extracted from a mid-sagittal slice from T1-weighted magnetic resonance images, and total area, length and curvature of the callosum were compared. The schizophrenia-spectrum group showed reductions in thickness of the genu across schizophreniform and schizoaffective disorder and schizophrenia, and the schizoaffective disorder group also showed an increase in thickness in the splenium and isthmus. None of these changes were seen in the affective disorder group, although a non-significant increase in the region of the isthmus and splenium was seen, particularly in the depressed group. Psychotic affective disorders do not show the anterior callosal reductions that are seen in the schizophrenia-spectrum group at first episode. The schizoaffective patients show additional posterior callosal expansions that may be a marker of an affective diathesis. This suggests that schizoaffective disorder may represent two interacting illness processes or be mid-way along a continuum of these two broad categories of illness at first psychosis
Executive control of working memory in schizophrenia
No full textThere is considerable evidence that working memory impairment is a common feature of schizophrenia. The present study assessed working memory and executive function in 54 participants with schizophrenia, and a group of 54 normal controls matched to the patients on age, gender and estimated premorbid IQ, using traditional and newer measures of executive function and two dual tasks-Telephone Search with Counting and the Memory Span and Tracking Task. Results indicated that participants with schizophrenia were significantly impaired on all standardised measures of executive function with the exception of a composite measure of the Trail Making Test. Results for the dual task measures demonstrated that while the participants with schizophrenia were unimpaired on immediate digit span recall over a 2-min period, they recalled fewer digit strings and performed more poorly on a tracking task (box-crossing task) compared with controls. In addition, participants with schizophrenia performed more poorly on the tracking task when they were required to simultaneously recall digits strings than when they performed this task alone. Contrary to expectation, results of the telephone search task under dual conditions were not significantly different between groups. These results may reflect the insufficient complexity of the tone-counting task as an interference task. Overall, the present study showed that participants with schizophrenia appear to have a restricted impairment of their working memory system that is evident in tasks in which the visuospatial sketchpad slave system requires central executive control. (c) 2005 Elsevier Ireland Ltd. All rights reserved
Speeding Up the Estimation of Expected Maximum Flows Through Reliable Networks
No full textIn this paper we present a strategy for speeding up the estimation of expected maximum flows through reliable networks. Our strategy tries to minimize the repetition of computational effort while evaluating network states sampled using the crude Monte Carlo method. Computational experiments with this strategy on three types of randomly generated networks show that it reduces the number of flow augmentations required for evaluating the states in the sample by as much as 52% on average with a standard deviation of 7% compared to the conventional strategy. This leads to an average time saving of about 71% with a standard deviation of about 8%.
Anteroposterior Gradients in Cerebral Glucose Use in Schizophrenia and Affective Disorders
No full text
- …
