Schizophrenia: Overview and Treatment Options

 

scholarly articles on schizophrenia

Mar 01,  · Schizophrenia is a devastating, complex disorder that has generated a vast and complicated body of literature. Understanding and Treating Schizophrenia undertakes an explanation of the history of the understanding of schizophrenia, as well as the variety of theories that have attempted to explain what causes it. The author also reviews the literature on various treatments for schizophrenia Cited by: 2. Memory impairments have been shown to compromise quality of life in patients with schizophrenia. Findings from a recent study show that insulin resistance may be an underlying cause of . Schizophrenia characteristically begins in young adult years and lasts throughout life, with only occasional recovery. 11,16 It is the case, however, that childhood-onset and adult/eldcrly-onset cases occur. The initial years of illness are often the most symptomatic and Cited by: 8.


The biology of schizophrenia


Language: English Spanish French. Scholarly articles on schizophrenia is an illness where the clinical signs and symptoms, course, and cognitive characteristics are well described.

Successful pharmacological treatments do exist, even though they are likely palliative. However, this broad knowledge base has scholarly articles on schizophrenia yet led to the identification of its pathophysiology or etiology The risk factors for schizophrenia are most prominently genetic and scientists anticipate that contributions from the new genetic information in the human genome will help progress towards discovering a disease mechanism.

Brain-imaging techniques have opened up the schizophrenic brain for direct inquiries, in terms of structure, neurochemisiry, and function. New proposals for diagnosis include grouping schizophrenia together with schizophrenia-related personality disorders into the same disease entity, and calling this schizophrenia spectrum disorder.

New hypotheses of pathophysiology do not overlook dopamine as playing a major role, but do emphasize the participation of integrative neural systems in the expression of the illness and of the limbic system in generating symptoms. Critical observations for future discovery are likely to arise from molecular genetics, combined with hypothesis-generating experiments using brain imaging scholarly articles on schizophrenia human postmortem tissue.

Schizophrenia is a chronic recurring psychotic illness that characteristically begins in young adult years and lasts a lifetime. The defining features of a schizophrenia diagnosis are hallucinations, delusions, paranoia, and thought disorder; these experiences are manifest in multiple sensory modalities and include abnormalities in all aspects of thought, cognition, scholarly articles on schizophrenia, and emotion Table I, see next, page.

It is not the loss but rather the malfunction of these functions that characterizes psychosis. Moreover, these features can fluctuate in intensity and across sensory substrates throughout the illness. The advent of antipsychotic drugs that are effective in the treatment of psychosis has exposed aspects of schizophrenia that were often overlooked when the florid presentation was untreated.

These aspects include cognitive dysfunction and primary negative symptoms. Primary negative symptoms include manifestations of alogia, anhedonia, and asociality, and are seen as part of the illness complex in many persons with schizophrenia, scholarly articles on schizophrenia.

In optimally treated outpatient populations in which psychosis is at least partially controlled, analyses show that negative symptoms and cognitive dysfunction contribute more strongly to overall psychosocial disability than do residual positive symptoms.

Schizophrenia characteristically begins in young adult years and lasts throughout life, scholarly articles on schizophrenia, with only occasional recovery. The initial years of illness are often the most symptomatic and include severe psychosocial deterioration. Middle-aged years are more benign; and in the elderly, frank symptom recovery has been described.

One can formulate schizophrenia as a disease of childbearing years, even though elderly persons with the illness still retain symptoms, scholarly articles on schizophrenia. Differing interactions between schizophrenia and aging have been reported. Some clinical samples show symptom improvement accompanied by psychosocial stability with aging, whereas other clinical samples show a precipitous age-related deterioration with loss of cognitive function and frank dementia.

A risk for schizophrenia is inherited, scholarly articles on schizophrenia. The disease occurs in all cultures and people around the world with rare exceptionsand with similar genetic risk estimates.

Association studies in schizophrenia suggest that schizophrenia is a complex multigenetic disorder. Many genes associated with the illness have been identified in the different studies.

Each risk factor confers a small risk, with the genetic factors being the most potent. Risk factors are thought to be multiplicative. Catastrophic pre- or perinatal events, like exposure to famine, scholarly articles on schizophrenia, radiation, or a maternal viral illness, especially during the second trimester, are significant risk factors for schizophrenia.

These early events do not have as much predictive power as the genetic factors, but can nonetheless explain significant variance. So the neural consequences that derive from these pre- or perinatal conditions do not inevitably lead to schizophrenia.

These conditions, however, may combine with other precipitating factors to facilitate illness onset. Environmental factors have also been suggested as risks for schizophrenia. These most prominently include the use of marijuana and possibly other forms of drug dependence, although this is less rigorously documented.

Trauma is often mentioned as a proximal risk factor for the illness, although the actual documentation for this is soft. The rearing environment characterized by emotion and stress is also often identified as a precipitant for schizophrenia.

Patients with schizophrenia characteristically perform more poorly on neuropsychological tasks than normal subjects, scholarly articles on schizophrenia. In addition, persons with schizophrenia consistently perform poorly scholarly articles on schizophrenia tasks that require sustained attention, sometimes called vigilance.

Also notable is the observation that in any single individual with the illness, symptoms fluctuate and change over time, making it hard to invoke permanent cerebral changes in neuronal function or circuitry as the basis of these cerebral abnormalities.

Measures of brain response to graded external stimuli have been characterized in schizophrenia and used to postulate its pathophysiology. These measures include primary eye movements in response to a smooth pursuit stimulus and electroencephalography FRG wave characteristics in response to a sensory stimulus. Smooth pursuit movements arc slow eye movements used to track a small moving object. The normal eye and brain use predictive smooth pursuit movements with occasional predictive saccades to follow a moving target efficiently.

In addition to smooth pursuit movements, saccadic eye movements have also been noted to be abnormal in schizophrenia. Signal-averaged EEG changes that are time-locked to sensory or cognitive events evoked potentials represent measures of individual information processing, independent of a behavioral response.

ETcments of these evoked potentials arc abnormal in schizophrenia, specifically the P element and the P50 wave. The P amplitude is consistently reduced in schizophrenia. There is an emerging formulation from several laboratories that schizophrenia is part of a larger set of disorders called schizophrenia spectrum disorders or schizotaxia; these disorders are related to each other in terms of genetics, scholarly articles on schizophrenia, symptom expression, cognitive characteristics, and, scholarly articles on schizophrenia, potentially, pathophysiology.

Schizophrenia itself may be the most severe manifestation of the class and characterized by the most flagrant psychosis and the worst psychosocial function Figure 1. But impairment at multiple levels and schizophrenialike symptoms span the entire spectrum group. Thaker, personal communication. First-degree scholarly articles on schizophrenia of schizophrenic probands may display many of the cognitive symptoms characteristic of schizophrenia, only without the florid psychosis.

These include task-related impairments in attention, language comprehension, scholarly articles on schizophrenia, verbal fluency, verbal memory, and spatial working memory. It is suspected that these cognitive disturbances in relatives occur predominantly in those with spectrum symptoms, however more study is required. Some adjustments in the criteria for spectrum disorder ie, loosening may be required for that diagnosis to capture all affected persons.

These observations may serve to broaden our concepts of schizophrenia, its manifestations, and beneficial treatment opportunities. One of the first discoveries in schizophrenia using modern imaging technologies was structural, first with computerized axial tomography CAT scanning and later with magnetic resonance imaging MRI. Johnstone and Crow 58 then Weinberger 59 described enlarged cerebral ventricles in persons with the illness. Over time, an overwhelming number of confirmations have accumulated.

However, this observation has served to redirect interest toward examining the brain for abnormal characteristics in persons with the illness. As structural imaging techniques have developed higher resolution, additional volumetric differences in the schizophrenic brain have been identified.

Several laboratories focusing on the superior temporal gyrus have reported volume decreases in schizophrenia and a correlation between the volume changes and clinical characteristics of the illness. Csernansky has gone on to identify hippocampal shape irregularities in schizophrenia.

When functional techniques for studying human brain became available, they were quickly applied to schizophrenia. Ingvar 66 was the scholarly articles on schizophrenia to note reduced prefrontal cortical blood flow in schizophrenia, scholarly articles on schizophrenia.

Subsequent early studies 8646768 served to focus scientific interest on the frontal cortex; this was a great advantage to the scientists who later followed up these ideas.

Subsequent functional imaging studies have noted an antipsychotic drug effect in prefrontal regions reduced neuronal activity 6970 and an influence of negative symptoms in prefrontal and inferior parietal cortex.

Current imaging approaches in schizophrenia utilize both structural scanning and neurochemical see Lamelle 72 in this issue and functional methodologies. The functional approaches are based on advances in the understanding of normal cognition also derived from functional imaging data.

Since the introduction of functional imaging techniques over 20 years ago, using either glucose metabolism or blood flow as the functional end points, several technical methodological principles have developed. Drug effects, especially antipsychotic compounds, are recognized as potentially informative in deciding on disease-related compared with drug-related differences between schizophrenia and normal test populations. Scholarly articles on schizophrenia with this focus, in addition to functional increases in the basal ganglia, also noted alterations in delimited cerebral areas, scholarly articles on schizophrenia, especially reductions in metabolism or regional cerebral blood flow rCBF in the frontal cortex anterior cingulate and middle frontal gyrus.

This approach has been problematic because of the altered performance levels between persons with schizophrenia and normal controls, which introduce a potential confounding element into the functional assessment during performance. Recent utilization of variable performance tasks have contributed to a solution here. While no single region has been identified in all laboratories, scholarly articles on schizophrenia, several distinct abnormalities are prominent and suggest, above all, the possibility that an abnormality of several systems in the brain underlies the illness.

Initially, the middle frontal scholarly articles on schizophrenia dorsolateral prefrontal region was identified as abnormal in schizophrenia 66 and has subsequently been tied to manifestations of primary negative symptoms in the illness.

A role of the basal ganglia cannot be ruled out. Functional magnetic resonance imaging fMRI studies of rCBF have produced a variety of results, often with conflicting data, possibly scholarly articles on schizophrenia of the augmented spatial resolution of this methodology. For example, during studies involving performance of a motor scholarly articles on schizophrenia in three different laboratories, subjects with schizophrenia were found to show no differences from normal subjects in rCBF, 7778 or increased rCBF, 79 or decreased rCBF 80 in the sensorimotor cortex.

Each of these studies suggested the potential of an interactive effect with previous or current antipsychotic medication. Tasks demanding higher-order cognitive functions, such scholarly articles on schizophrenia attention scholarly articles on schizophrenia working memory, have also resulted in conflicting data. For example, one study found an increase in frontal cortical rCBF in schizophrenia compared with healthy persons with a working scholarly articles on schizophrenia task, whereas two other laboratories reported decreases in this area with a similar task.

Additional studies in this area will hopefully define the subject variables, performance demands, or the illness phase contribution s that are important for an explanation of these discrepancies. Use of fMRI is rapidly increasing in all academic centers, and so progress will not lag in this area. The functional imaging studies from our laboratory have compared persons with schizophrenia with matched healthy individuals while performing an auditory recognition task in an overlearncd, practiced condition, with normals with a similar task performance.

The two groups of volunteers performed similarly on accuracy and tone interval. Those schizophrenic volunteers who had a similar performance to normal subjects on the basis of accuracy, but required wide tone disparities to do so, had not only rCBF reductions in the ACC, but. These observations invoke the concept of a circuit failure, possibly of limbic cortex, and affect those areas of prefrontal cortex whose functions are highly influenced by the ACC.

Some of our functional imaging studies have focused on the hippocampus. Because statistical parametric mapping SPM analytic techniques rely on group average data and because the hippocampus is both small and variably located in humans, scholarly articles on schizophrenia, magnetic resonance-guided hand sampling producing volumes of interest VOIs is necessary to adequately represent.

We used magnetic resonance-guided individual VOI image sampling and made several interesting observations about, hippocampal function. Second, rCBF in the schizophrenic hippocampus is greater than in the normal hippocampus bilaterally, and across different task conditions. This last observation suggests that the scholarly articles on schizophrenia hippocampus, which already evidences elevated rCBF in the medication-free state, is more sensitive to glutamatergic inhibition.

This observation is consistent with some of our other postmortem findings showing reduced NM'DA receptor NR, subunits in schizophrenia, and hence potential reductions in the number of functional N. DA receptors.

Hypotheses to explain the manifestations of schizophrenia have been posited for centuries. The finding a half century ago that antipsychotic drugs block dopamine receptors in brain 82 and scholarly articles on schizophrenia reduce psychotic symptoms strongly supported the idea that an overactive dopaminergic system causes schizophrenia.

Many years and many experiments later, evidence to support, this idea has now been generated scholarly articles on schizophrenia modern imaging tools. As knowledge of normal brain function has revealed intricate and complexly interacting neural systems, so these ideas have also been applied to schizophrenia.

 

 

scholarly articles on schizophrenia

 

Memory impairments have been shown to compromise quality of life in patients with schizophrenia. Findings from a recent study show that insulin resistance may be an underlying cause of . Schizophrenia is a complex disorder that requires prompt treatment at the first signs of a psychotic episode. Clinicians must consider the potential for nonadherence and treatment-related adverse effects when developing a comprehensive treatment plan. Although patients can increase adaptive functioning through available pharmacological and Cited by: Mar 01,  · Schizophrenia is a devastating, complex disorder that has generated a vast and complicated body of literature. Understanding and Treating Schizophrenia undertakes an explanation of the history of the understanding of schizophrenia, as well as the variety of theories that have attempted to explain what causes it. The author also reviews the literature on various treatments for schizophrenia Cited by: 2.