Can we predict psychostimulant use in youths? A study with structural equation modeling analysis.

Knowing which factors predict the use of psychostimulant drugs among youths is important for designing preventive programs and the identification of youths with the highest probability of use, to avoid some of the problems that can be derived from it. The purpose of this study is to examine the relationship between perceived availability, risk perception, personality traits, antisocial personality patterns, and use of other substances in the prediction of psychostimulant use. The sample was composed by 1,177 youths (584 males and 593 females) aged 14 to 25 in Spain, recruited randomly, stratified by lifetime use- non use of psychostimulants (cocaine or ecstasy). The path which best predicts psychostimulant use is: Personality traits-legal substance use-cannabis use-psychostimulant use. The next path is: Personality traits-antisocial personality patterns-psychostimulant use. Risk perception and perceived availability were significant in the prediction, but made a smaller contribution. The results of this study suggest that the model evaluated can predict psychostimulant use in youths. This model can be seen as a useful tool for developing preventive strategies and for identifying those youths that are at risk for problems related to drug use.

First-time admissions for opioid treatment: cross-sectional and descriptive study of new opioid users seeking treatment.

BACKGROUND: The purpose of this study was to gain an understanding of the profiles of the new treatment demands posed by opioid addicts between 2005 and 2010 at the addictive disorders assistance units in Galicia, Spain. METHODS: A cluster analysis was performed using data from 1,655 treatment entrants. Clusters were constructed using sociodemographic and medicolegal variables. A cluster analysis was also conducted according to age. Once clusters were defined, their association with the following variables was analyzed: age at first use of opioids, years of use, frequency of opioid use in the previous month, psychiatric treatment, cocaine use, existence of a drug-dependent partner, and source of referral. RESULTS: Four clusters were obtained in the main analysis. Cluster 1 (34.01%) consisted of young males, cluster 2 (16.19%) consisted of not-so-young males, cluster 3 (32.62%) consisted mainly of older males and a small group of females, and cluster 4 (17.18%) was made up entirely of women. With regard to age-related clusters, two clusters were obtained in those under the age of 30 years: cluster 1 (73%) without medicolegal complications and cluster 2 (27%) with medicolegal complications. For those over the age of 30 years, two clusters were obtained: cluster 1 (53.92%) with hardly any medicolegal complications and cluster 2 (46.08%) with medicolegal complications. CONCLUSION: Cluster analysis suggests that there have been no substantial changes in variables indicating greater severity in this new group of patients. Women are likely to seek help earlier, which reduces their duration of opioid use. The younger the patient, the shorter the duration of opioid use and the greater the likelihood of cessation of intravenous use. Public health systems should use a two-pronged treatment strategy of short but intense cessation therapies for women and younger treatment entrants and longer maintenance and replacement therapies for older treatment entrants with more psychosocial and medical complications.

[Do adolescents who use stimulants have a different personality?]. / Tienen una personalidad distinta los adolescentes consumidores de psicoestimulantes?

Stimulant consumption is especially important in our context because its use has greatly increased in recent years. The aim of the present study is to analyze the differences between stimulant users and nonusers (under 18 years old) in personality characteristics assessed with the MACI. The sample comprises 398 youths between 14 and 17 years old who were selected through random sampling in their homes or in recreational night spots. Results show important differences in personality features between stimulant users and nonusers. Stimulant users are characterized by having unruly, forceful, oppositional and borderline-tendency personality prototypes.

GENERACIÓN DE SEÑALES SIMULADAS DE ECG ABDOMINAL A PARTIR DE UN MODELO ABDOMINAL 3D / GENERATION OF SYNTHETIC ABDOMINAL ECG SIGNALS FROM AN ABDOMINAL 3D MODEL

El electrocardiograma abdominal es una técnica de monitoreo promisoria para la vigilancia en el periodo prenatal, ya que presenta facilidad de adquisición y permite la supervisión materna y fetal simultáneamente. La separación de estas señales es complicada y no existe una forma estandarizada de evaluar la efectividad de algoritmos reportados en la literatura. Basados en un modelo de dipolo propagado en el abdomen materno tridimensional, el presente trabajo propone la implementación de un sistema de generación de señales de ECG abdominal, con características controlables de simulación de condiciones reales: interferencias, variabilidad de periodos cardiacos, número de canales, ubicación de electrodos y posición fetal. Con el sistema desarrollado se generaron 50 señales sintéticas de prueba que mostraron una correlación de 0,99 con respecto a valores esperados en la relación señal-interferencia, sin diferencias significativas en la regresión (p>0.05); mientras que el coeficiente de correlación para la relación señal a ruido fue de 0.87 con diferencias significativas en la regresión por debajo de los -20 dB (p<0.05). En conclusión, el sistema propuesto proporciona señales de ECG abdominal con condiciones similares a las de señales reales, lo cual facilita la adecuada evaluación de algoritmos de separación de ECG materno y fetal a partir del ECG abdominal.

Abdominal ECG is one of the most promising monitoring techniques for fetal surveillance in the antenatal period, as it presents easy availability and allows the maternal and fetal monitoring simultaneously. However, separation of these signals is complicated and there is no standardized way to evaluate the effectiveness of separation algorithms reported in the literature. Based on the dipole model spread through the three-dimensional maternal abdomen, this paper proposes the implementation of a system for the generation of abdominal ECG signals with controllable characteristics simulating real conditions by interference, heart period variability, number of channels , electrodes location and fetal position. Using the developed system, 50 synthetic test signals were generated and compared with desired values. Results showed a correlation of 0.99 with respect to expected values in the signal interference ratio, with no significant differences in the regression (p>0.05); while the correlation coefficient was 0.87 for the signal to noise ratio, with significant differences below -20 dB (p<0.05) in the regression. In conclusion, the proposed system provides abdominal ECG signals showing similar conditions to those of real signals, and comprises a tool that ensures proper evaluation of separation algorithms of maternal and fetal ECG from abdominal ECG.