Browsing by Subject "Schizophrenia"
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Item Astrocytic Contribution to the Glutamatergic Transmission in Schizophrenia(2011-02-01T19:33:32Z) Stan, Ana Despina; Tamminga, CarolSchizophrenia is a chronic mental disorder encompassing an array of cognitive and behavioral manifestations. Although the disease molecular pathophysiology remains essentially unknown, evidence exists for abnormalities within all the main neurotransmitter systems and various cortical and subcortical brain structures, albeit with no unifying/overarching hypothesis connecting the existent knowledge. Moreover, no current animal model or biological construct reproduces the complexity of the disease with acceptable validity. In my work I have taken a multidisciplinary approach to study the live and postmortem human brains of people with schizophrenia, focusing specifically on the glutamatergic abnormalities in the hippocampus, one brain region repeatedly found to bear structural, molecular, and blood flow abnormalities in the disease. I have started with the in vivo measurement of glutamate and glutamine using magnetic resonance spectroscopy, thus getting a “high-level” sense of the glutamatergic transmission changes in the hippocampi of subjects with schizophrenia. Concretely, I have found that untreated people with schizophrenia have reduced levels of glutamate compared to their healthy counterparts, but this reduction can be partially reversed by antipsychotic medication. To allow for a more “small-scale” characterization of the glutamatergic transmission impairments, I have used postmortem brain tissue to zoom in on the glutamatergic synapse, viewed as a “tripartite synapse”. Apart from the pre- and postsynaptic neurons, the third component is represented by the astrocyte, the brain glial cell that is responsible for most of the glutamate recycling and that attunes the glutamatergic synapse to the overall energetic metabolism of the brain. I have found that glutamate recycling is impaired in schizophrenia, selectively in the dentate gyrus, one of vii the hippocampal subregions, and the specific abnormalities reside in the glutamate transporters, responsible clearing up synaptic glutamate.Item Attention deployment and conceptual inclusiveness of normals and schizophrenics(Texas Tech University, 1968-08) Sturm, Bessie Betty,Not availableItem A computational model of language pathology in schizophrenia(2010-12) Grasemann, Hans Ulrich; Miikkulainen, Risto; Hoffman, Ralph E.; Mooney, Raymond J.; Love, Bradley C.; Ballard, Dana H.; Kuipers, Benjamin J.No current laboratory test can reliably identify patients with schizophrenia. Instead, key symptoms are observed via language, including derailment, where patients cannot follow a coherent storyline, and delusions, where false beliefs are repeated as fact. Brain processes underlying these and other symptoms remain unclear, and characterizing them would greatly enhance our understanding of schizophrenia. In this situation, computational models can be valuable tools to formulate testable hypotheses and to complement clinical research. This dissertation aims to capture the link between biology and schizophrenic symptoms using DISCERN, a connectionist model of human story processing. Competing illness mechanisms proposed to underlie schizophrenia are simulated in DISCERN, and are evaluated at the level of narrative language, the same level used to diagnose patients. The result is the first simulation of a speaker with schizophrenia. Of all illness models, hyperlearning, a model of overly intense memory consolidation, produced the best fit to patient data, as well as compelling models of delusions and derailments. If validated experimentally, the hyperlearning hypothesis could advance the current understanding of schizophrenia, and provide a platform for simulating the effects of future treatments.Item COMT Genotype, Schizophrenia, and Dopamine Transmission(2011-02-01T19:33:08Z) Birchfield, Thomas Richard; Ghose, SubrotoCatechol-o-methyltransferase (COMT) catabolism is the primary mechanism for dopamine signal deactivation in the dorsolateral prefrontal cortex, an area of the brain associated with working memory. Working memory deficits are found in persons with schizophrenia and their unaffected siblings. A single nucleotide polymorphism of the COMT gene results in a MET-->VAL shift at codon 158, increased enzyme thermostability, and increased enzymatic activity. The hypothesized result of this shift is decreased dopamine transmission in the brain area associated with working memory due to increased dopamine catabolism. The current study analyzed the effect of COMT genotype and schizophrenia on the mRNA expression of genes known to be influenced by dopamine signal transmission with qPCR of RNA extracted from high-quality, fresh-frozen postmortem dorsolateral prefrontal cortex tissue. While no significant difference was observed between genotypes, a significant effect of diagnosis was found for the D1 dopamine receptor, COMT, and tyrosine hydroxylase, the rate-limiting step of dopamine synthesis. The current findings support a model decreased dopamine synthesis and increased catabolism leading to deficient dopamine signal transmission in persons with schizophrenia.Item Emotional blunting and social isolation in schizophrenics and psychosis-prone college students(Texas Tech University, 1992-12) Lemon, Martin EdwardNot availableItem Estimation of direct and indirect costs of treating schizophrenia for community-dwelling US residents(2011-12) Desai, Pooja Rajiv; Lawson, Kenneth Allen, 1952-; Barner, Jamie C.; Rascati, Karen L.Schizophrenia is a chronic and debilitating disease that affects approximately one percent of the US population and exerts a disproportionately high financial burden on the society. The objective of this study was to estimate the direct and indirect costs of schizophrenia among community-dwelling US residents and identify patient characteristics associated with high schizophrenia-related direct costs. Patients with a diagnosis of schizophrenia (ICD-9 code 295) or other non-organic psychoses (ICD-9 code 298) between January 1, 2005 and December 31, 2008 were identified from the Medical Expenditure Panel Survey (MEPS). To estimate direct costs, the following cost categories were identified: inpatient hospitalizations, outpatient visits, emergency department visits, office-based physician visits, home healthcare visits, and prescription medications. The following cost categories were identified to estimate indirect costs: caregivers’ costs and cost of lost productivity due to missed work days, reduced employment, and suicide. Logistic regression was used to compare patients belonging to the high-cost group and to the low-cost group. All analyses were carried out using SAS version 9.2 (SAS Institute Inc., Cary, North Carolina). The weighted average number of patients with schizophrenia identified for each year was 757,893. The annual direct and indirect costs were estimated at $3.96 billion and $15.35 billion, respectively. The mean annual direct medical schizophrenia-related cost per patient was $5,586. For each one-year increase in age, patients were 5.7% less likely to be in the high-cost group. Patients with a spouse were 77.7% less likely than patients without a spouse to be in the high-cost group. Healthcare providers and policymakers can use these cost estimates to better understand the economic burden of schizophrenia and identify services and subgroups of patients associated with the highest costs. This would help in the provision of healthcare services to patients with schizophrenia and in the optimization of patient outcomes.Item The influence of stigma of mental illnesses on decoding and encodting of verbal and nonverbal messages(2013-05) Imai, Tatsuya; Dailey, René M.Stigmas associated with depression and schizophrenia have been found to negatively impact the communication those with mental illness have with others in face-to-face interactions (e.g., Lysaker, Roe, & Yanos, 2007; Nicholson & Sacco, 1999). This study attempted to specifically examine how stigma affects cognitions, emotions, and behaviors of interactants without a mental illness toward those with a mental illness in online interactions. In this experimental study, 412 participants interacted with a hypothetical target on Facebook, who was believed to have depression, schizophrenia, or a cavity (i.e., the control group). They were asked to read a profile of the target on Facebook, respond to a message from the target, and complete measurements assessing perceived positive and negative face threats in the target's message, perceived facial expressions of the target, induced affect, predicted outcome value, and rejecting attitudes towards the target. Results revealed that the target labeled as schizophrenic was rejected more and perceived to have lower outcome value than the target without a mental illness or labeled as depressive. However, there were no significant differences in any outcomes between the depression and control groups. The mixed results were discussed in relation to methodological limitations and possible modifications of previous theoretical arguments. Theoretical and practical contributions were considered and suggestions for future research were offered.Item Left frontal neuropsychological functioning in paranoid and nonparanoid schizophrenics(Texas Tech University, 1983-12) Langell, Mary ElizabethNot availableItem Psychometric Properties and Clinical Utility of the Texas Functional Living Scale Short Form in Individuals with Schizophrenia(2013-09-10) Rogers, Kathryn Rayne; Casenave, GeraldBACKGROUND: Schizophrenia is a chronic mental disorder presenting with psychotic and cognitive symptoms that lead to impairments in independent living and psychosocial functioning. Individuals with schizophrenia demonstrate cognitive deficits in areas of attention, executive functioning, memory, and language. Additionally, schizophrenia has been associated with impairments in activities of daily living (ADLs) such as toileting and the ability to feed one’s self and instrumental activities of daily living (IADLs) such as taking medication, financial management, communication, and transportation. METHODS: Twenty-six participants diagnosed with schizophrenia or schizoaffective disorders were recruited from the University of Texas Southwestern Medical Center’s Division of Translational Neuroscience of Schizophrenia’s IRB approved Database Registry for Psychotic Disorders and completed a neuropsychological test battery which included the Texas Functional Living Scale (TFLS) and University of California San Diego (UCSD) Performance-based Skills Assessment (UPSA). IBM SPSS Statistics (SPSS v. 19.0) was used to perform Pearson correlation coefficients and multiple regression analyses to identify which subscale(s) of the TFLS had the highest predictive ability for examining IADLs to create a possible short form and to identify which subscales of the TFLS long form have the strongest correlation to neurocognitive measures used in the study. The present pilot study used the Type I error rate at .10; a 90% confidence interval. RESULTS: Results of the analysis indicated that the Time and Money Calculation subscales of the TFLS long form significantly correlated with more neurocognitive measures than the UPSA. Specifically, these two subscales had a higher number of moderate to strong correlations with the neurocognitive measures compared to the UPSA. Results also indicated the TFLS short form to have a stronger correlation with the UPSA (r =.59, p < .003) compared to baseline correlations of the TFLS long form and the UPSA (r = .34, p < .112), which suggests that the Time and Money Calculations subscales of the TFLS can be used as a valid short form of the TFLS in the assessment of IADLS in schizophrenia. DISCUSSION: Overall, the short form of the TFLS appears to be a valuable addition to standard neuropsychological assessment batteries given its numerous correlations with neurocognitive measures. Results also suggest that the TFLS short form is a stronger measure for detecting IADL impairments compared to its original long form and the UPSA.Item The relationship between the public’s belief in the potential of recovery and level of mental illness stigma(2011-05) Barczyk, Amanda Nicole; Davis, King E.; Thompson, Sanna J.; von Sternberg, Kirk; Alexander, Laurie; Springer, David W.Mental health conditions are highly prevalent in the U.S. Approximately two thirds of individuals who have a diagnosable mental health condition do not seek treatment; stigma is a major contributing factor. Stigma can lead to a fear of pursuing one’s goals, loss of self-esteem and a hesitancy to engage in society. This dissertation was a secondary data analysis of 1,437 adults who participated in the 2006 General Social Survey topical modules utilizing vignettes to examine mental health issues. Multiple-group structural equation modeling examined the relationship between respondents’ level of prejudicial attitudes and social distance (i.e., stigma) toward individuals who have a mental health condition and their belief in the potential of recovery. This relationship was examined for mental health conditions in general and across four groups (i.e., alcohol dependence, major depression, schizophrenia and troubled person). The relationship was further explored by testing if previous contact with an individual who has received treatment was a mediator. Findings indicate that the belief in recovery leads to lower levels of social distance. This finding was true for each group. In addition, prejudicial attitudes were found to be a predictor of one’s level of social distance for each group. Parameter invariance was found for all variables except income. In the group of respondents given the vignette depicting a troubled person, those with a lower income were more likely to have lower levels of prejudicial attitudes. In the group of respondents given the vignette depicting an individual with alcohol dependence, those with lower income were more likely to have higher levels of prejudicial attitudes and social distance. While the variable previous contact was not a mediator, it was found that males, respondents of minority background and those with less education were less likely to have had previous contact with an individual who has received mental health treatment. Results from this dissertation indicate a need to place emphasis on the probability of recovering from a mental health condition when developing stigma reducing strategies. Results also highlight the need to focus on the recovery and empowerment of individuals with mental health conditions in education, practice and policy.Item Sources of cognitive impairment in paranoid and nonparanoid schizophrenia.(Texas Tech University, 1975-08) Blevens, James KeithNot availableItem The effects of age and sex on the modifications of perceptual judgements of a schizophrenic population(Texas Tech University, 1967-08) Cull, John GNot availableItem The effects of age and sex on the modifications of perceptual judgements of a schizophrenic population(Texas Tech University, 1967-08) Cull, John GNot availableItem The effects of instructional manipulations on Rorschach responses in high-creative, low-creative, and schizophrenic groups(Texas Tech University, 1984-12) Odgers, Robert PNot availableItem The psychophysiological correlates of high and low experiencing clients in psychotherapy(Texas Tech University, 1972-08) Kane, Robert LouisNot availableItem The relationship between relevant and irrelevant information in chronic "schizophrenia"(Texas Tech University, 1968-08) Alumbaugh, Richard VernonNot availableItem The relationship between schizophrenia and reading retardation in adolescent males(Texas Tech University, 1972-08) Gottlieb, Michael CraigNot availableItem The utility of Cogntive Behavioral Therapy in the treatment of the schizophrenic patient(2010-05) Borkowski, Jennifer Nickole; McCarthy, Christopher J.; Rude, StephanieSchizophrenia is a complex and pervasive brain disorder that effects millions of people in the United States. There are three tiers of symptoms associated with the disorder, they include: positive symptoms, negative symptoms and thought disorders. The most common method of treatment for this disorder involves the use of antipsychotic medications, and while these medications have been shown to be effective in treating certain positive symptoms of the disorder, they have a tendency to be less effective in treating the negative cluster of symptoms and the thought disorders that can be highly debilitating for patients. The aim of this review was to determine the level of effectiveness of psychosocial treatments for the disorder, and in particular to look in to Cognitive- Behavioral Therapy (CBT) as an adjunctive method of treatment to be used in conjunction with medication. By performing searches using the PsycInfo, ERIC, EBSCO and Medline databases, the researcher was able to draw the conclusion that while there are some complications and areas of improvement in study construction, CBT can indeed be a helpful method of treatment for many patients. Importantly, CBT tends to be a very flexible treatment that can accommodate many different combinations of symptoms at varying levels or severity and stages of the illness. A discussion of a possible model of treatment that uses CBT was also undertaken to provide readers with a practical example of how this form of treatment can be used.