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Since Meese and Rogoff (1983) results showed that no model could outperform a random walk in predicting exchange rates. Many papers have tried to find a forecasting methodology that could beat the random walk, at least for certain forecasting periods. This Element compares the Purchasing Power Parity, the Uncovered Interest Rate, the Sticky Price, the Bayesian Model Averaging, and the Bayesian Vector Autoregression models to the random walk benchmark in forecasting exchange rates between most South American currencies and the US Dollar, and between the Paraguayan Guarani and the Brazilian Real and the Argentinian Peso. Forecasts are evaluated under the criteria of Root Mean Square Error, Direction of Change, and the Diebold-Mariano statistic. The results indicate that the two Bayesian models have greater forecasting power and that there is little evidence in favor of using the other three fundamentals models, except Purchasing Power Parity at longer forecasting horizons.
Functional magnetic resonance imaging (fMRI) is a neuroimaging technique increasingly used for both patient care and clinical research. This techniche provides a space-time high-resolution able to detect small changes in regional brain activation.Ojbectives: the aim of this study was to compare patterns of regional brain activation in patients with eating disorders (ED) and healthy volunteers during emotional stimulation.
Materials and methods
A group of 13 young female ED outpatients was selected using DSM-IV criteria and 13 young healthy female volunteers with no significant differences in sociodemographic or environmental data. fMRI was used to examine the neural responses after visual stimulation with neutral and fearful images, taken from the IAPS (International Affective Picture System) and selected a region of interest (ROI) aproach to examine the function of the amygdala in emotional processing.Data processing and higher level analysis were carried out using FSL (fMRI's Software Library).
ED patients showed significantly greater rigth amygdala activation to the fearful images versus neutral images than healthy control subjects (p < 0.02)
A higher right amygdala response to processing of fearful stimuli was observed in ED patients compared to healthy volunteers. This emotional dysregulation in the affective response to unpleasant stimuli would correlate with a maladaptative response and therefore justify disruptive behaviours in this patients.
Recent reports show that psychological functions such as working memory, attention and intention produce overlapping functional activation in the inferior parietal region. Task activation related to attention shifting, theory of mind and agency also overlaps in the inferior parietal and posterior superior temporal regions. We hypothesized that schizophrenic symptoms may stem from abnormal activity in these regions.
To understand the relationship between brain abnormalities and symptoms in schizophrenia.
To show that abnormal activity in the inferior parietal and posterior superior temporal regions during working memory is related to certain schizophrenic symptoms.
14 schizophrenic and 14 normal control subjects were tested using functional magnetic resonance imaging (fMRI) in conjunction with a verbal working memory paradigm. Symptoms were assessed using the SAPS and SANS scales.
As hypothesized, activity in the posterior superior temporal sulcus during working memory was correlated with levels of delusions in schizophrenic subjects. Connectivity strength between regions in the inferior parietal and anterior insula language related regions was related to levels of auditory hallucinations.
These regions are part of speech and voice perception and production networks. Voice perception during conversation also involves gesture processing, working memory and dynamic shifting of attention, as well as social cognition (e.g. theory of mind) and self/other (agency) representation. Overactivation of this social communication system could result in the symptoms of schizophrenia. We will present the results in the context of a framework implicating these regions in the generation of most of the symptoms of schizophrenia.
Diffusion tensor imaging (DTI) is a relatively new imaging technique that is being increasingly used in different types of psychiatric patologies to characterize white matter microstructural organization in this kind of disorders. In the present study we use DTI to explore the structure of the white matter of borderline personality disorder (BPD) patients, using a novel voxel-based approach, tract-based spatial statistics (TBSS), to analyze the data.
Methods and materials
DTI was performed in a 1.5T MRI unit in 9 young male patients with a DSM-IV defined BPD and 14 healthy male control subjects (no significant age difference between groups).Voxel wise analysis was performed using TBSS (diffusion toolbox of FSL- functional MRI Software Library) to localize regions of white matter showing significant changes of fractional anisotropy (FA). Additional high resolution three dimensional datasets were also acquired and normalised white matter volume was estimated with SIENAX (part of FSL).
The TBSS analysis revealed a statistically significant decrease in FA at the anterior part of the body and the genu of the corpus callosum and frontal white matter. This finding is consistent with previously reported findings of subtle prefrontal white matter abnormalities in BPD.
Significant white matter tract alterations in patients with BPD where observed in frontal regions involved in emotional, behavioural and cognitive regulation, and these abnormalities may be linked to key aspects of psychopatology in these patients.
Despite the use of antipsychotics as monotherapy is considered to be the standard treatment for schizophrenia and other psychotic disorders, many studies prove that antipsychotic polypharmacy (AP) is more frequent than expected in accordance to the experts' guidelines.
To analyze the prescription of long-acting risperidone (LAR) for schizophrenic patients discharged after being admitted in our BHU and its relationship with the AP.
Material and methods:
This retrospective study reviews the antipsychotics prescribed to those discharged patients diagnosed as schizophrenic who were admitted in our BHU during 2005. A total of 209 patients are included. The data are analyzed in relation to the prescription of antipsychotics for discharged patients on LAR and the antipsychotic combinations for those patients discharged on another antipsychotic regime, both as a complementary treatment and to cover the LAR therapeutic window.
57 patients (27%) were discharged on LAR. 42% were treated with benzodiazepines, 56% with anticholinergics and 16% with mood stabilizers. 79% of patients treated with LAR were discharged with another antipsychotic in combination: oral risperidone (58%), followed by amisulpiride (18%). Similar dosages were used in patients discharged only on LAR and those used in patients prescribed with more than one antipsychotic (p>0.05).
LAR could be an efficient strategy both to enable the treatment compliance and to achieve a monotherapy treatment. Despite LAR is frequently combined with another antipsychotic, in most cases oral risperidone is used, consequently avoiding the use of two antipsychotics of different kind in the same patient.
Until a patient is diagnosed of schizophrenia often receives another diagnoses. Reasons can be multiple: difficulty for the differential diagnosis in prodromical phases, comorbidity with other psychiatric disorders, abuse of substances, behaviour disorders, etc.
The aim of this study is to analyze the diagnosis that received in the first admission a sample of schizophrenia diagnosed patients.
Patients and Methods
Health histories of schizophrenia diagnosed patients who entered the Brief Hospitalization Unit of Dr R. Lafora Hospital in 2005 are analyzed. A total number of 162 patients is obtained. The diagnosis that received in the first entrance to our hospital is extracted from the health history.
A 64,4% of the patients with diagnosis of schizophrenia in 2005 were diagnosed of schizophrenia in their first entrance. Another 8,6% were diagnosed of psychotic nonspecified disorder. A 7,4% did not receive psychiatric diagnosis. 6,4% brief psychotic episode. A 3,1% psychotic disorder induced by substances. A 2,5% schizoaffective disorder. A 0,6% bipolar disorder. And a 6,2% received other diagnoses.
The data of our study indicated that a 28,2% of the schizophrenia diagnosed patients received another diagnosis previously (a 7,4% did not receive diagnosis to the discharge). Of the previously data, a 21,4% received diagnoses of psychotic disorders different from schizophrenia. This must probably response to temporary criteria for the diagnosis of schizophrenia (brief psychotic episode) prodromical forms (psychotic nonspecified disorder) and to substances use (psychotic disorder induced by substances) that make difficult the diagnosis in the early phases of the disease.
A study of N-acetyl-aspartate (NAA) can provide data of interest about cortical alterations in psychotic illnesses. Although a decreased NAA level in the cerebral cortex is a replicated finding in chronic schizophrenia, the data are less consistent for bipolar disease. On the other hand, it is likely that NAA values in schizophrenia may differ in men and women.
We used proton magnetic resonance spectroscopy (1H MRS) to examine NAA levels in the prefrontal cortex in two groups of male patients, one with schizophrenia (n = 11) and the other with bipolar disorder (n = 13) of similar duration, and compared them to a sample of healthy control males (n = 10). Additionally, we compared the degree of structural deviations from normal volumes of gray matter (GM) and cerebrospinal fluid (CSF) in the dorsolateral prefrontal cortex.
Compared to controls, schizophrenia and bipolar patients presented decreased NAA to creatine ratios, while only the schizophrenia group showed an increase in CSF in the dorsolateral prefrontal region. There were no differences in choline to creatine ratios among the groups.
These data suggest that the decrease in NAA in the prefrontal region may be similar in schizophrenia and bipolar disorder, at least in the chronic state. However, cortical CSF may be markedly increased in schizophrenia patients.
Andalusia is the most highly populated (7,849,799 hab.) region of the Spanish State. It has all the sanitary domains under its own Health Service (Consejería de Salud), and it has undertaken a deep reorganization of the psychiatric services, establishing a new model based on the mental health communitarian alternative that is already completely implanted. Rates of readmission are a method to assess the quality of care and an important tool in the planning of services of mental health.
The aim of this study is to establish if readmission rates are influenced by Human Resources in Psychiatric Community Devices.
Part of FIS Project PI05/90061 ‘Patterns of General Hospital Psychiatric Units Overuse’.
MBDS is a system of hospital register that gathers all the discharges produced in the andalusian hospitals. It is totally trustworthy from 1995, and we have processed data up to 2004.
Our Data Set register 101234 hospital admissions of psychiatric patients.
The number of admissions from patients who enter three times or more throughout the year has been: 22.66%(1995); 24.66% (1996); 31.01%(1997); 30.72%(1998); 34.07%(1999); 35.35%(2000); 36.92%(2001); 32.93%(2002); 31.20%(2003) and 29.36%(2004).
On the other hand, it has been an increase in Mental Health Human Resources Rates: 24.23-100.000 inhab-(1998); 24.19 (1999); 26.01(2000); 28.04(2001); 29.83(2002); 29.16(2003); 29.34(2004) and 29.90(2005).
Increasing human resources in psychiatric community devices do not change revolving-door rates in general hospital acute psychiatric units in a community mental health system.
Use of antipsychotic drugs in monotherapy is considered the standard treatment for schizophrenia and other psychotic disorders. Nevertheless, exist numerous studies that show as the polypharmacy with antipsyhotics (PA) is much more frequent than it would be expected attending to experts recommendations.
The objective is to compare the prescription habits, in reference to the PA as well as to other psychotropic drugs, of 8 psychiatrists of a Psychiatric Hospitalization Unit.
Material and methods:
Review of the psychotropic drugs prescribed as maintenance treatment in schizophrenia patients (n=200) at outcome in 2005.
55,5% of 200 studied patients were registered with PA. This frequency oscillates between 78% and the 33,3% based on the psychiatrist. The patients received an average of 3,06 (DS 1,26) of psychotropic drugs; rank between 2,69 (DS 1,10) and 3,38 (DS 0,52) in relation to the psychiatrist. As maintenance treatment at outcome, it was prescribed an average of 1.61 (DS 0.65) of antipsychotics, rank 1.33 (DS 0,49) – 2,00 (DS 0.7). 33,2% patients received anticholinergics (17,1%-100% according to psychiatrist). Benzodiazepines were prescribed to 62,2% of patients (17,1%-100%). Mood stabilizer in the 16,7% of the cases (8%-41%). It is observed that those psychiatrists who use more PA use less benzodiazepines and anticholinergics.
PA extended practice in spite of therapeutic guides recommendations. Although differences between the psychiatrists from the study are observed, most of the patients have 3 psychotropic drugs as maintenance treatment at outcome: 1 or 2 antipsychotics, benzodiazepines and anticholinergic drugs.
There is a subpopulation of schizophrenic patients sometimes referred to as “revolving door” patients due to the frequency of readmissions in psychiatric units. Substance abuse and noncompliance with medication are the most important factors related to frequency of hospitalization. It has been related also with the number of previous admissions.
To describe the profile of the “revolving door” schizophrenic patient.
This retrospective study examines demographic and diagnostic features of the patients who met criteria for schizophrenia and have been admitted in our brief hospitalization unit during 2005. 209 adult patients were included. We compared the data of patients with only one admission (n=132) with those who have been admitted two or more times (n=77) in the period of study.
We detected a significative difference between the two groups in the number of previous hospitalizations. The group with one admission during 2005 had 3.75 previous hospitalizations (SD 5.34) vs. 6.37 previous hospitalizations (SD 5.75) for the group with two or more admissions during 2005 (p<0.01). No differences were found between the two groups about gender, age, the subtype of schizophrenia, substance abuse, the presence of another psychiatric illness, or the length of the stay.
Our study shows that the number of previous readmissions could be used as a main predictor of the risk of rehospitalization. This fact supports the results of other studies. However, we have not found the substance abuse as a predictor of earlier readmission, as other studies do.
To study the short-term effect of treatment with quetiapine on prepulse inhibition (PPI) deficits of the startle reflex in schizophrenia patients.
Subjects and methods
Using PPI, we studied a group of 21 schizophrenia patients and 16 controls. Seventeen of the patients were re-tested with PPI after 21 days of treatment with quetiapine.
At baseline, an almost significant decrease in PPI was found in the patients as compared to the controls. PPI measurements did not change in the patients after 21 days of treatment with quetiapine, despite their clinical improvement.
Our results suggest that short-term quetiapine treatment may not modify PPI measures in schizophrenia patients.
The 28-item version of the General Health Questionnaire (GHQ-28) developed by Goldberg and Hillier in 1979 is constructed on the basis of a principal components analysis of the GHQ-60. When used on a Spanish population, a translation of the GHQ-28 developed for an English population may lead to worse predictive values.
We used our Spanish sample to replicate the entire process of construction of the GHQ-28 administered in a primary-care setting.
Two shorter versions were proposed: one with six scales and 30 items, and the other with four scales and 28 items.
The resulting GHQ-28 was a successful adaptation for use on the Spanish sample. When compared with the original version, only 21 items were the same. Moreover, contrary to the English version, which groups sleep problems and anxiety in the same scale, a scale with items related exclusively to ‘Sleep disturbances’ was found.
Antipsychotic treatment and psychosocial interventions can reduce the risk of relapse and prevent functional impairment. The DAI questionnaire enables the effect of treatment perceived by patients to be evaluated.
To assess the attitude of patients to treatment on hospital discharge compared when the drug of admission is modified on discharge and when it is maintained.
A multicenter, naturalistic, retrospective study to analyse the immediate clinical outcome after a medical intervention in 1346 patients with schizophrenia in acute units in Spain. Clinical progression of the first five days of hospital intervention and at hospital discharge was collected retrospectively. Afterwards, the DAI questionnaire was completed.
1238 patients completed the DAI questionnaire. The average score was 15.6 (range 10–20). In the group of patients where the main antipsychotic drug during hospital stay was the same as that received at the time of hospital discharge, no statistically significant differences were found vs the group where the antipsychotic was modified (15.6 vs 15.4, p = 0.630).
At acute units the effect of the drug perceived by patients assessed through the DAI questionnaire on hospital discharge is similar for all antipsychotic drugs whether the treatment is modified on hospital admission or not.
Compliance is essential to achieve the best results in serious mental illness like schizophrenia.
It was expected that the use of second-generation oral antipsychotics with less extrapyramidal side effect profile would improve the compliance, but the results do not support these expectations except in the case of risperidone long-acting injection.
The aim of this study is to assess the degree of compliance in outpatients who were started treatment with RLAI while they were hospitalized for an acute psychotic episode in psychiatric unit.
A retrospective study was conducted by reviewing medical records of hospitalized patients for psychotic episodes over the past 5 years in three hospitals in Mallorca (Balearic Islands, Spain) -Hospital de Manacor, Hospital son Llatzer and Hospital de Inca). Due to computerization of medical records, we knew the degree of compliance with treatment and outcome in outpatient clinics. We designed a case report data (CRD) to assess specific variables in our study that was completed for each patient.
The mean duration of treatment in patients who continue with RLAI was 38.8 months. Overall. 69.5% continued with the treatment after 5 years. The patients who continued treatment were rehospitalazed 20% less than the ones who discontinued.
The compliance with RLAI in outpatients was high even in patients with substances abuse. The patients who remain on treatment from hospital discharge have less readmissions. The most common dosis of RLAI is 50 mg. Lack of insight was the most frequent cause of discontinuation.
Relapses are common and a higher number of relapses involve a greater cognitive impairment of the patient. Prevention of relapses is therefore the primary objective of treatment.
To establish why a sample of patients with schizophrenia experience relapses and are admitted to acute units as a result.
A multicenter, naturalistic, retrospective study assessing medical intervention in 1346 patients with schizophrenia admitted to acute units in Spain, assessing the following causes of relapses: non-compliance, lack of efficacy, drug abuse, stress and high incidence of side effects.
90.8% of patients were admitted for relapse. Reasons for admission were non-compliance in 67.1% (77.2% due to lack of insight and 30.59% due to drug abuse), lack of therapeutic efficacy in 27.2%, and drug abuse in 24.3%. In addition, stress and a high incidence of side effects in 5.8% of patients were other reasons for relapse.
Non compliance is the main reason for relapses followed by lack of efficacy. The results appear to confirm that drug abuse might influence in a direct (drug abuse itself) or indirect (non compliance because of drug abuse) way in a higher number of relapses.
The type of treatment used for patients with schizophrenia and an improvement at Day 3 can affect the length of stay and symptom outcome.
To determine the influence of improvement at Day 3 in the lenght of hospital stay and hospital discharge in the case of patients with schizophrenia admitted to acute units.
A multicenter, naturalistic, retrospective study evaluating medical intervention in 1346 patients with schizophrenia in acute units in Spain.
The mean of hospital stay days was 23.3 (range 1–260 days). 49.5% of patients with improvement at Day 3 had a shorter length of hospital stay. 78.7% received treatment with antipsychotics prior to admission. The most common drugs were risperidone, olanzapine and quetiapine. 99.8% and 99.7% were treated during hospital stay and on discharge, respectively. The drugs most commonly used were paliperidone ER, risperidone and olanzapine. 99.8% of patients with improvement measured by GCI at Day 3 and 100% with improvement at Day 5 had improved at discharge. The percentage of patients requiring use of benzodiazepines or physical/mechanical restriction decreased as the days passed.
The three most commonly used drugs during admission were effective, but the action of paliperidone ER is to be noted (its use increased from 4% prior to admission to 43% and 44% during hospital stay and on discharge, respectively). The results of this study appear to confirm that symptom improvement should be obtained as early as the first week of treatment to achieve a shorter hospital stay.
Excessive cortical cerebrospinal fluid (CSF) has been acknowledged as a possible marker of a gray matter loss. This excess in schizophrenia is found predominantly in the prefrontal and temporal regions. We hypothesized that the poorer global outcome and treatment response in males with schizophrenia are related to a greater cortical volume loss as compared to females.
Subjects and methods
In order to test this hypothesis we have used magnetic resonance imaging (MRI) to study the cortical (prefrontal, temporal, and hemispheric) CSF values in a group of 85 patients with schizophrenia, of whom 56 were males and 29, females. We calculated the residual values of CSF in the patients based on the data pertaining to 45 control subjects and linear regression, from which the normal effects of age and intracranial volume were discounted. These residual scores constitute a quantitative measurement of the excess of CSF due to the disease.
Males, but not females, presented a trend-level significant excess of left prefrontal CSF. The prefrontal and temporal residual values were significantly associated with illness duration in males, but not in females.
These results conform to the worse outcome and the higher severity of structural abnormalities generally found in schizophrenia in male subjects.
Our data support the hypothesis of accelerated prefrontal cortical loss in males, but not in females with schizophrenia.
In patients with acute clinical symptoms, a short hospital stay and prevalent therapeutic objectives aimed at controlling symptoms overcome the clinician's concern for the functionality levels that will be even more significant after discharge.
To establish the clinical condition of patients admitted to acute/short-stay units in the first five days of hospital stay and on hospital discharge.
A multicenter, naturalistic, retrospective, observational study to evaluate clinical assessment (CGI) obtained in patients with schizophrenia after treatment at the time of admission and on hospital discharge.
The mean score of the CGI questionnaire decreases from 5.3 recorded on admission to 4.3 on Day 5 and 3 on discharge. On Day 5 of hospital stay, symptoms had improved in 57.3% of cases. In 30.9% of cases there were no changes and in 1.7% symptoms had worsened. In 86.3% of patients symptoms had improved at discharge. 100% of patients with clinical improvement at Day 5 had a clinically significant improvement on hospital discharge.
Clinical improvement in the first five days after hospital admission appears to lead to a better clinical prognosis on hospital discharge. Hospital discharge should be scheduled from admission, so treatment choice should be geared to looking to control symptoms in the first few days and allow for better social and personal functioning after discharge.