Active clinical trials for "Schizophrenia"

Background: The prevalence of cigarette smoking among individuals with schizophrenia is noticeably higher than in the general population, and smoking cessation attempts frequently are unsuccessful in this population. Little is known about the effects of cigarette/nicotine craving in individuals with schizophrenia. Researchers are interested in learning more about how craving affects people with schizophrenia and developing new ways to treat cravings and improve the effectiveness of smoking cessation therapies and treatments. In recent years, virtual reality (VR) has been studied to determine whether it can be used to induce craving by using life-like cue settings. VR cues involving cigarette use, including images of cigarettes and scent cues of tobacco smoke, may be used to elicit craving in smokers. Researchers are interested in learning more about how individuals with schizophrenia respond to specific VR cues and settings. Objectives: To determine the feasibility of using a contextual real-world paradigm using virtual reality involving cigarette smoking in people with schizophrenia. To examine if virtual reality cues will elicit craving in smokers with schizophrenia. Eligibility: - Current smokers (five or more cigarettes per day for at least 1 year) between 18 and 45 years of age who have been diagnosed with schizophrenia/schizoaffective disorder. Design: The study will involve three sessions, with an initial screening visit, a test session, and a follow-up session. Screening visit: Participants will be screened with a medical and psychiatric history, and will answer questions about smoking history, current smoking habits and craving patterns, and general anxiety levels. This session will also introduce participants to the operation and use of the VR equipment. Participants who are comfortable using the VR system will return within 2 days for the test session. Test session: Participants will use the VR equipment to view neutral scenes and scenes that are designed to elicit cravings for cigarettes. After viewing each scene, participants will answer questions about their overall mood, anxiety levels, and any cigarette cravings they may have. Follow-up session: Participants will return 1 week after the VR session to answer questions about mood, anxiety levels, and current smoking habits and craving patterns.

Background: Several studies of risk perception have demonstrated a common bias known as unrealistic optimism, in which individuals feel they are less likely than other people to experience unpleasant or harmful events in their lives, but more likely to experience pleasant or beneficial events. Previous research has indicated that individuals with schizophrenia have less of a sense of unrealistic optimism about adverse events than individuals without schizophrenia. However, research on risk perception in schizophrenia is sparse, primarily reporting on behaviors and decisions in the laboratory that likely are influenced by risk perception. Risk perception among substance users may be viewed in two separate categories: perception of vulnerability to adverse events and perception of vulnerability to negative outcomes associated with substance use. Research in both areas has yielded mixed results. Researchers are interested in studying the connections among schizophrenia, addiction, and risk perception in order to develop better drug use prevention and treatment programs for people with and without schizophrenia. Objectives: - To compare unrealistic optimism bias in people with and without schizophrenia and/or drug dependence, and its association with actual risky behavior. Eligibility: Individuals between 18 and 64 years of age who fall into one of the following study categories: diagnoses of both drug dependence (marijuana or cocaine) and schizophrenia/schizoaffective disorder diagnosis of drug dependence only (marijuana or cocaine) diagnosis of schizophrenia/schizoaffective disorder only healthy volunteers with no history of drug use or serious mental disorder Design: The study will require a single visit to the research center for a 5- to 6-hour session. Participants will complete questionnaires on medical and behavioral history, complete tests of thinking skills like memory and attention, complete a brief computerized decision-making task, and answer questions about risk perception. Participants will also provide urine samples and breath carbon monoxide measurements to test for recent use of tobacco and other substances.

Gamma-aminobutyric acid (GABA) is the principal inhibitory neurotransmitter in the mammalian central nervous system. It is involved in a wide spectrum of physiological functions, from sleep and sedation to convulsions. A defect in neurotransmission involving GABA in schizophrenia was first propsed in early 1970s, based on neuropathologcial evidence, yet there is a lack of molecular genetic evidence. Recently, we carried out a pilot study on a region of the GABA-A receptor β2 subunit gene on chromosome 5 and found significant association for single nucleotide polymorphisms (SNPs) in the gene sequence with occurrence of schizophrenia. The current proposal aims to validate this important finding and to conduct a thorough scanning of the complete gene sequences of the GABA-A receptor subunit genes in this chromosomal region, including the three major subunits α1, β2 and γ2. We shall collect samples from Hong Kong Chinese subjects for a case-control study using haplotype maps and comparing the SNP haplotype frequencies in the receptor genes, and hence examine whether these genes are in association with schizophrenia, or other schizophrenia-spectrum disorders, including Alzheimer's disease presenting with psychotic symptoms. Based on the observation that patients suffering from the catatonic subtype of schizophrenia respond particularly well to benzodiazepines, which bind specifically to GABA-A receptors, we shall also perform data analysis in terms of correlating SNP association with schizophrenia subtypes. Association of GABA-A receptor genes with schizophrenia would be a major step forward to determining whether these genes are susceptibility genes for schizophrenia, thereby paving the way to more effective diagnosis and treatment for this debilitating disease.

The purpose of this study is to determine whether atypical antipsychotic drugs (commonly prescribed for treating schizophrenia) induce changes in anthropometry and metabolism, including alteration in insulin sensitivity and/or insulin secretion by the pancreas, when given to lean, non-diabetic, individuals who are antipsychotic drug(s)-naïve, and free of metabolic syndrome at enrollment.

To assess the efficacy of 24-week treatment with quetiapine in patients with schizophrenia or schizoaffective disorder

People with chronic mental disorder such as schizophrenia and alcohol abuse are high risk groups for developing osteoporosis. To evaluate the prevalence of bone mineral density in men patients with schizophrenia with alcohol abuse, the investigators will compare bone mineral density between patient with schizophrenia with and without alcohol abuse.

The purpose of this non-interventional, observational and international registry study is to document the prescribing patterns in daily clinical practice and to assess long term treatment outcomes related to initiation of treatment with oral antipsychotics in a naturalistic setting.

The purpose of this study is to explore efficacy, tolerability and safety of paliperidone Extended Release (ER) in 250 schizophrenia patients who started treatment with paliperidone ER in a naturalistic setting.

This study is designed to test the hypothesis that plasma osmolality is linked with cortical glutamate concentrations in the brain. It also investigates whether the glutamate response in schizophrenia is enhanced compared to healthy controls.

The primary objective of the study is to evaluate the pharmacokinetics of XR quetiapine fumarate(300mg,600mg,and 800mg once-daily) in Chinese schizophrenic patients .