The Mexican magnetic resonance imaging dataset of patients with cocaine use disorder: SUDMEX CONN.

Cocaine use disorder (CUD) is a substance use disorder (SUD) characterized by compulsion to seek, use and abuse of cocaine, with severe health and economic consequences for the patients, their families and society. Due to the lack of successful treatments and high relapse rate, more research is needed to understand this and other SUD. Here, we present the SUDMEX CONN dataset, a Mexican open dataset of 74 CUD patients (9 female) and matched 64 healthy controls (6 female) that includes demographic, cognitive, clinical, and magnetic resonance imaging (MRI) data. MRI data includes: 1) structural (T1-weighted), 2) multishell high-angular resolution diffusion-weighted (DWI-HARDI) and 3) functional (resting state fMRI) sequences. The repository contains unprocessed MRI data available in brain imaging data structure (BIDS) format with corresponding metadata available at the OpenNeuro data sharing platform. Researchers can pursue brain variability between these groups or use a single group for a larger population sample.

Psychological impact of sociodemographic factors and medical conditions in older adults during the COVID-19 pandemic in Mexico / Impacto psicológico de factores sociodemográficos y condiciones médicas en adultos mayores durante la pandemia de COVID-19 en México

Abstract Introduction Older adults are not only at a higher medical risk during the COVID-19 pandemic, but they may also be a group particularly vulnerable to mental health diminishing. Objective To analyze the effect of some sociodemographic factors (sex and age) and medical conditions (diabetes and hypertension) on mental health and concerns about COVID-19 in a sample of older adults. Method A non-probabilistic sample of 2,992 older adults (37.7% men and 62.3% women) was selected, with an average age of 70.45 years (SD = 7.31). Participants were given the Impact of Event Scale-6 (IES-6), the Patient Health Questionnaire (PHQ-9), the Generalized Anxiety Disorder-7 (GAD-7), a questionnaire of concerns about COVID-19, and a sociodemographic questionnaire. Participants' answers were captured via Google Forms. Results The results showed that women had greater concerns about COVID-19 than men. The findings in general showed significant effects, with women showing higher scores in depressive symptoms, anxiety, and greater stress generated in addition by the impact of the event. Differences concerning event-related stress and depression were found in relation to subgroups by age. Discussion and conclusion These finding could serve for the planning and development of strategies that provide attention to the mental health of this population group.

Resumen Introducción Los adultos mayores no sólo presentan un mayor riesgo médico durante la pandemia de COVID-19, sino que también pueden ser particularmente vulnerables a la disminución de la salud mental. Objetivo Analizar el efecto de algunos factores sociodemográficos (sexo y edad) y condiciones médicas (diabetes e hipertensión) sobre la salud mental y las preocupaciones sobre COVID-19 en una muestra de adultos mayores. Método Se seleccionó una muestra no probabilística de 2,992 adultos mayores (37.7% hombres y 62.3% mujeres), con una edad promedio de 70.45 años (DE = 7.31). Los participantes recibieron la Estala de Impacto de Evento-6, el Cuestionario de Salud del Paciente-9, el Trastorno de Ansiedad Generalizada-7, un cuestionario de preocupaciones sobre COVID-19 y un cuestionario sociodemográfico. Resultados Las mujeres presentaron mayores preocupaciones por COVID-19 que los hombres. Las respuestas de los participantes se capturaron en Google Forms. Resultados En general, los hallazgos mostraron efectos significativos, siendo las mujeres quienes presentaron puntuaciones más altas en síntomas depresivos y ansiedad, así como mayor estrés asociado a evento. Además, se encontraron efectos diferenciados por subgrupos de edad en relación con estrés asociado a evento y síntomas depresivos. Discusión y conclusión Estos hallazgos pudieran ser útiles para planificar y desarrollar estrategias que brinden atención a la salud mental de este grupo de población.

Cognitive and clinic profile of volatile substance users / Perfil cognitivo y clínico de usuarios de sustancias volátiles

Abstract Introduction Inhalant use disorder has increased in spite of its adverse medical consequences. Due to the inherent difficulties of working with this population, so far there has been no quantifiable clinical evidence of the cognitive characteristics of inhalants users in early withdrawal and the clinic effect of consumption time. Objective To evaluate the clinical and cognitive performance of inhalant users and the clinic effects of consumption time. Method A cross-sectional study in which 28 adult users of inhalants were included, divided in two groups according to their consumption time: less than or greater than seven years. They were all evaluated in terms of clinical and neuropsychological values. Results Consumers of inhalant showed presence of craving (M = 479.14, SD = 213.51), altered frontal behavior before (M = 119.18, SD = 29.53) and now (M = 130, SD = 33.03), sleeping problems (M = 8.93, SD = 3.4), and cognitive difficulties (inhibitory control, planning, decision-making, working memory, verbal fluency, and cognitive flexibility); all these tasks were statistically significant (p = < .05). Discussion and conclusion Executive functioning is impaired with inhalant use disorder; these alterations increase with withdrawal and craving and changes remain independent from the use time.

Resumen Introducción El trastorno por uso de inhalables ha aumentado a pesar de las consecuencias médicas adversas. Debido a las dificultades que entraña trabajar con estas poblaciones, hasta hace poco no había evidencia clínica cuantificable de las características cognitivas de los usuarios de inhalables en la abstinencia temprana y de los efectos clínicos del tiempo de consumo. Objetivo Se analizó el rendimiento clínico y cognitivo de usuarios de inhalables y los efectos clínicos del tiempo de consumo. Método Estudio transversal en el que se incluyeron 28 adultos usuarios de inhalables, divididos en dos grupos dependiendo del tiempo de consumo, menor o mayor a siete años. Todos fueron evaluados en términos de valores clínicos y neuropsicológicos. Resultados Los consumidores de inhalables mostraron presencia de craving (M = 479.14, SD = 213.51), comportamiento frontal alterado antes (M = 119.18, SD = 29.53) y actualmente (M = 130, SD = 33.03), problemas para dormir (M = 8.93, SD = 3.4) y dificultades cognitivas (control inhibitorio, planificación, toma de decisiones, memoria de trabajo, fluidez verbal y flexibilidad cognitiva); todas estas tareas fueron estadísticamente significativas (p = < .05). Discusión y conclusión El funcionamiento ejecutivo se ve afectado en el trastorno por uso de inhalables. Estas alteraciones aumentan en la abstinencia y en la apetencia, y los cambios se mantienen independientes del tiempo de uso.

Clinical and behavioral profile of young inhalant users.

INTRODUCTION: Currently, misuse inhalants is increasing: addictive potential has been demonstrated in several studies. Until now there was no quantifiable clinical evidence of behavioral characteristics inhalant users. Main objective was to evaluate craving, impulsivity, frontalized behaviors and recognition of emotions in young inhalant users. METHOD: Eleven male, aged 15-22 years (17.73±2.14), schooling 3-12 years (8.18±2.56) were evaluated. RESULTS: Evaluation showed that inhalant users exhibit signs of craving, high ranges of impulsivity, frontal behavioral deficits and difficulties detection of emotional expressions. CONCLUSIONS: In inhalants addiction, symptoms of craving and behavioral alterations are exhibited, time use increases frontal behaviors.

Perfil clínico y conductual de jóvenes usuarios de inhalables / Clinical and behavioral profile of young inhalant users

Introducción. En la actualidad el uso indebido de inhalables está aumentando: el potencial adictivo se ha demostrado en diversos estudios. Hasta ahora no había evidencia clínica cuantificable de las características conductuales de los usuarios de inhalables. El objetivo principal fue evaluar el craving, la impulsividad, los comportamientos frontalizados y el reconocimiento de emociones en jóvenes usuarios de inhalables. Método. Fueron evaluados once varones, edades entre 15-22 años (17,3 ± 2,14), escolaridad entre 3-12 años (8,18 ± 2,56). Resultados. La evaluación evidenció que los usuarios de inhalables exhiben indicios de craving, rangos elevados de impulsividad, déficits comportamentales del sistema frontal y dificultades para la detección de expresiones emocionales. Conclusión. En la adicción a inhalables se exhiben síntomas de craving y alteraciones comportamentales, el tiempo de uso incrementa los comportamientos frontales

Introduction. Currently, misuse inhalants is increasing: addictive potential has been demonstrated in several studies. Until now there was no quantifiable clinical evidence of behavioral characteristics inhalant users. Main objective was to evaluate craving, impulsivity, frontalized behaviors and recognition of emotions in young inhalant users. Method. Eleven male, aged 15-22 years (17.73±2.14), schooling 3-12 years (8.18 ± 2.56) were evaluated. Results. Evaluation showed that inhalant users exhibit signs of craving, high ranges of impulsivity, frontal behavioral deficits and difficulties detection of emotional expressions. Conclusions. In inhalants addiction, symptoms of craving and behavioral alterations are exhibited, time use increases frontal behaviors

Identifying cognitive deficits in cocaine dependence using standard tests and machine learning.

There is a growing need to address the variability in detecting cognitive deficits with standard tests in cocaine dependence (CD). The aim of the current study was to identify cognitive deficits by means of Machine Learning (ML) algorithms: Generalized Linear Model (Glm), Random forest (Rf) and Elastic Net (GlmNet), to allow more effective categorization of CD and Non-dependent controls (NDC and to address common methodological problems. For our validation, we used two independent datasets, the first consisted of 87 participants (53 CD and 34 NDC) and the second of 40 participants (20 CD and 20 NDC). All participants were evaluated with neuropsychological tests that included 40 variables assessing cognitive domains. Using results from the cognitive evaluation, the three ML algorithms were trained in the first dataset and tested on the second to classify participants into CD and NDC. While the three algorithms had a receiver operating curve (ROC) performance over 50%, the GlmNet was superior in both the training (ROC = 0.71) and testing datasets (ROC = 0.85) compared to Rf and Glm. Furthermore, GlmNet was capable of identifying the eight main predictors of group assignment (CD or NCD) from all the cognitive domains assessed. Specific variables from each cognitive test resulted in robust predictors for accurate classification of new cases, such as those from cognitive flexibility and inhibition domains. These findings provide evidence of the effectiveness of ML as an approach to highlight relevant sections of standard cognitive tests in CD, and for the identification of generalizable cognitive markers.

Funcionamiento cognitivo en sujetos con trastorno de dependencia a cocaína y crack durante la abstinencia temprana / Cognitive functions of subjects with cocaine and crack dependency disorder during early abstinence

Introducción. Los efectos cognitivos causados por el consumo de cocaína y crack, especialmente los déficits de las funciones ejecutivas, aumentan la probabilidad de un comportamiento de búsqueda de drogas e interfieren en la capacidad de los usuarios de asimilar y participar en los programas de rehabilitación. Objetivo. Determinar en la abstinencia temprana el estado de las funciones ejecutivas, la impulsividad y la ansiedad (craving) en consumidores de cocaína y crack. Sujetos y métodos. Este estudio transversal tuvo una muestra de 60 hombres, con una edad media de 31,38 ± 7,26 años, distribuidos en tres grupos: usuarios que inhalan cocaína (CDP-I; n = 15), con una edad de inicio de consumo de 23,13 ± 7,2 años; consumidores de cocaína en crack (CDP-C; n = 26), con una edad de inicio de consumo de 20,81 ± 4,21 años, y un grupo control de sujetos sin adicción (n = 19). Se aplicaron evaluaciones sociodemográficas, clínicas y cognitivas. Resultados. Los datos mostraron diferencias significativas en las puntuaciones del nivel socioeconómico e impulsividad. Los grupos de consumidores tienen puntuaciones más bajas con respecto al grupo control. El grupo CDP-C mostró rendimientos pobres en comparación con el grupo CDP-I y el grupo control en las pruebas de Berg, torre de Londres, números en orden y sustracción directos. El grupo CDP-I mostró una menor puntuación en la planificación comparada con los otros dos grupos. Conclusiones. En la abstinencia temprana, los consumidores de crack manifiestan mayor número de déficits, principalmente en la memoria de trabajo, la planificación y la flexibilidad cognitiva

Introduction. Cognitive effects caused by cocaine and crack consumption, especially deficits in executive functions may increase the likelihood of drug-seeking behaviour and interfere with the ability of users to assimilate and participate in rehabilitation programs. Aim. To determine in early abstinence the state of executive functions, the impulsiveness and craving in cocaine and crack consumers. Subjects and methods. This cross-sectional study functions, with a sample of 60 male aged between 31.38 ± 7.26 years old, distributed in three groups: inhaled cocaine users (CDP-I; n = 15), with 23.13 ± 7.2 age of onset of consumption; crack cocaine users (CDP-C; n = 26), with 20.81 ± 4.21 age of onset of consumption, and a control groups of no-addiction individuals (n = 19). Sociodemographic, clinical and cognitive assessments were applied. Results. The data showed that significant differences in socioeconomic level score and impulsiveness. Consumer groups have with lower scores with respect the control group. CDP-C group showed poor performances compared to the CDP-I and control groups, in the Berg Test, Tower of London, numbers in the direct order and subtraction. CDP-I group showed less score in planning compare with the other two groups. Conclusions. In early abstinence crack users manifest a greater number of deficits, mainly in working memory, planning and cognitive flexibility

A novel experimental paradigm to evaluate children and adolescents diagnosed with attention-deficit/hyperactivity disorder: Comparison with two standard neuropsychological methods.

INTRODUCTION: In this study we evaluated a recently developed test, the Ball Search Field Task (BSFT) as a neuropsychological tool for measuring cognitive and behavioral performance of individuals with disorders such as attention-deficit/hyperactivity disorder (ADHD), which are frequently accompanied by cognitive deficits and a lack of behavioral inhibition. The task provides a complementary method of assessment that attempts ecological validity by drawing on challenges faced in real-world situations. In this task, energetic costs and gross sensorimotor feedback are involved, as participants are required to search for targets in a large open area. METHOD: We compared performance on the BSFT in a clinical sample of children and adolescents with a diagnosis of ADHD with their scores on two widely used neuropsychological tools, the Tower of London (ToLo) and the Behavior Rating Inventory of Executive Function (BRIEF). RESULTS: We found no correlations between scores on the BRIEF and those on either the BSFT or ToLo. However, we found moderate correlations between rule violations on ToLo and several BSFT variables, suggesting the capacity of these tests to detect common aspects of executive dysfunction. CONCLUSIONS: These findings, although modest, encourage further study of tasks like the BSFT, which may help assess cognitive dysfunction found in neurodevelopmental disorders such as ADHD in ecologically valid situations.

Evaluation of children with ADHD on the Ball-Search Field Task.

Searching, defined for the purpose of the present study as the displacement of an individual to locate resources, is a fundamental behavior of all mobile organisms. In humans this behavior underlies many aspects of everyday life, involving cognitive processes such as sustained attention, memory and inhibition. We explored the performance of 36 treatment-free children diagnosed with attention-deficit hyperactivity disorder (ADHD) and 132 children from a control school sample on the ecologically based ball-search field task (BSFT), which required them to locate and collect golf balls in a large outdoor area. Children of both groups enjoyed the task and were motivated to participate in it. However, performance showed that ADHD-diagnosed subjects were significantly less efficient in their searching. We suggest that the BSFT provides a promising basis for developing more complex ecologically-derived tests that might help to better identify particular cognitive processes and impairments associated with ADHD.

Evidence of validity of an inhalant-craving questionnaire.

Inhalants are substances widely used as recreational drugs: their addictive potential has been demonstrated by many studies. There is no reported measurable evidence of craving in inhalant users. The main goal of this study was to design and obtain evidence of validity of the score of a questionnaire for the evaluation of inhalant craving (ICQ) in a Mexican population sample. The ICQ is a type of visual analog scale with ten items. Face validity was evaluated by a group of experts in the addiction field. Reviewers considered the completeness, semantics, and sentence structure to guarantee a conceptual representation of the items. The final ICQ was applied to a sample of 520 Mexican high school students, 46% women and 54% men, between 12-19 years of age (M=15.18; SD=1.48), from 7th to 12th grades. The internal consistency of the ICQ showed a Cronbach's Alpha of 0.947. The 10 items were grouped into one single factor, with a factor loading above 0.74 for each of them. ROC analysis breakpoint was located at 18.5 mm with a sensitivity of 0.855 and specificity of 0.753. Thirty-three per cent (n= 172) of the student population evaluated reported the use of inhalants at some point in their lifetimes, with an average of misuse beginning at 13.6 years of age. The ICQ showed adequate psychometric properties, suggesting that the instrument may be considered a useful tool for screening for craving in young inhalant users.

Los inhalables son sustancias ampliamente utilizadas como drogas recreativas: su potencial adictivo ha sido demostrado por numerosos estudios. No hay reportada evidencia medible del craving en usuarios de inhalables. El objetivo principal de este trabajo fue diseñar y obtener las evidencias de validez de las puntuaciones en un cuestionario para la evaluación del craving a sustancias inhalables (ICQ) en una muestra de población mexicana. El ICQ es un tipo de escala análoga visual de diez ítems. La validación de apariencia fue evaluada por un grupo de expertos en el campo de las adicciones. Los revisores consideraron la integridad, la semántica y la estructura de los enunciados, para garantizar una representación conceptual de los ítems. La versión final del ICQ fue aplicada a una muestra de 520 estudiantes mexicanos, 46% mujeres y 54% hombres, con edad comprendidas entre 12-19 años (M=15.18; SD=1.48), con años de escolaridad entre 7-12 años. La consistencia interna del ICQ mostró un Alfa de Cronbach de 0.947. Los 10 ítems se agruparon en un solo factor, con una carga factorial por encima de 0.74 para cada uno de ellos. El análisis ROC mostró que el punto de corte se localizó a 18.5 mm con una sensibilidad de 0.855 y especificidad de 0.753. El 33% (n=172) de la población de estudiantes evaluados reportó el uso de inhalables en algún momento de su vida, con un promedio de edad de inicio de 13.6 años. El ICQ mostró propiedades psicométricas adecuadas, lo que sugiere que el instrumento puede ser una herramienta útil para el tamizaje de craving en jóvenes usuarios de inhalables.

Evidencias de validez de un cuestionario de craving a inhalables / Evidence of validity of an inhalant-craving questionnaire

Los inhalables son sustancias ampliamente utilizadas como drogas recreativas: su potencial adictivo ha sido demostrado por numerosos estudios. No hay reportada evidencia medible del craving en usuarios de inhalables. El objetivo principal de este trabajo fue diseñar y obtener las evidencias de validez de las puntuaciones en un cuestionario para la evaluación del craving a sustancias inhalables (ICQ) en una muestra de población mexicana. El ICQ es un tipo de escala análoga visual de diez ítems. La validación de apariencia fue evaluada por un grupo de expertos en el campo de las adicciones. Los revisores consideraron la integridad, la semántica y la estructura de los enunciados, para garantizar una representación conceptual de los ítems. La versión final del ICQ fue aplicada a una muestra de 520 estudiantes mexicanos, 46% mujeres y 54% hombres, con edad comprendidas entre 12-19 años (M=15.18; SD=1.48), con años de escolaridad entre 7-12 años. La consistencia interna del ICQ mostró un Alfa de Cronbach de 0.947. Los 10 ítems se agruparon en un solo factor, con una carga factorial por encima de 0.74 para cada uno de ellos. El análisis ROC mostró que el punto de corte se localizó a 18.5 mm con una sensibilidad de 0.855 y especificidad de 0.753. El 33% (n=172) de la población de estudiantes evaluados reportó el uso de inhalables en algún momento de su vida, con un promedio de edad de inicio de 13.6 años. El ICQ mostró propiedades psicométricas adecuadas, lo que sugiere que el instrumento puede ser una herramienta útil para el tamizaje de craving en jóvenes usuarios de inhalables

Inhalants are substances widely used as recreational drugs: their addictive potential has been demonstrated by many studies. There is no reported measurable evidence of craving in inhalant users. The main goal of this study was to design and obtain evidence of validity of the score of a questionnaire for the evaluation of inhalant craving (ICQ) in a Mexican population sample. The ICQ is a type of visual analog scale with ten items. Face validity was evaluated by a group of experts in the addiction field. Reviewers considered the completeness, semantics, and sentence structure to guarantee a conceptual representation of the items. The final ICQ was applied to a sample of 520 Mexican high school students, 46% women and 54% men, between 12-19 years of age (M=15.18; SD=1.48), from 7th to 12th grades. The internal consistency of the ICQ showed a Cronbach’s Alpha of 0.947. The 10 items were grouped into one single factor, with a factor loading above 0.74 for each of them. ROC analysis breakpoint was located at 18.5 mm with a sensitivity of 0.855 and specificity of 0.753. Thirty-three per cent (n= 172) of the student population evaluated reported the use of inhalants at some point in their lifetimes, with an average of misuse beginning at 13.6 years of age. The ICQ showed adequate psychometric properties, suggesting that the instrument may be considered a useful tool for screening for craving in young inhalant users

[Concurrent validity in Mexican college population of the adult ADHD self report scale]. / MVlidación concurrente en población mexicana universitaria de la escala de autorreporte de TDAH en el adulto de la Organización Mundial de la Salud.

INTRODUCTION: In order to make a valid adult ADHD diagnostic, the clinician must overcome a series of difficulties, the main of which may be the fact that the current DSM-IV diagnostic criteria for ADHD were designed for children, hence having valid and reliable instruments in order to screen for possible patients be very helpful. OBJECTIVE: To validate the ASRS for its use on Mexican college population through concurrent validity with the FASCT scale. MATERIAL AND METHODS: We evaluated 447 (287 women, average age 23.59 years) undergraduate students from 4 universities in Mexico City. All participants answered the ASRS and FASCT scales. RESULTS: Positive and statistically significant correlations were found between the ASRS and FASCT (r = 0.79) and the agreement in diagnostic was moderate (k = 0.58). CONCLUSIONS: ASRS seems to have adequate concurrent validity with the FASCT, nevertheless further research comparing it with a semi-structured or highly structured interview is needed.

Análisis de fuentes del EEG en pacientes tratados con estimulación magnética transcraneal a 5 Hz como tratamiento antidepresivo / Electroencephalographic source analysis in patients receiving 5-Hz transcranial magnetic stimulation as antidepressant treatment

Transcranial Magnetic Stimulation (rTMS) is a technique that allows noninvasive electrical stimulation of the cortex with few side effects. An antidepressant effect has been proposed when rTMS is delivered over prefrontal dorsolateral cortex (DLPFC) ≥5Hz. Quantitative EEG studies have shown increases in alpha and theta power bands as well as frontal interhemispheric asymmetries in most recordings from depressed patients. rTMS over left DLPFC at 5Hz involve a safer and more tolerable procedure, and its neurophysiological correlates has not been explored using EEG source analysis. The aim of this research was to study changes in EEG sources using VARTERA method in a group of patients with major depressive disorder (MDD) treated with 5Hz rTMS over left DLPFC as single or combined treatment with escitalopram. Methods 18 patients with DSM-IV MDD diagnosis without treatment for the current episode were included. Subjects were randomly assigned to one of two groups: A) rTMS+escitalopram 10mg, n=9; B) rTMS+placebo, n=9. Subjects received 15 sessions of rTMS on a daily basis. In order to compare changes in EEG sources two recordings were obtained, prior and after treatment. HDRS, BDI and HARD were used for clinical assessments. Results All patients of group A and eight patients of group B showed response to treatment (considered as a reduction of 50% in HDRS score). An increase in absolute power at 9.37Hz and 10.17Hz in temporal and postcentral gyrus on the left hemisphere was found in group B. Absolute power in those frequencies was decreased in the same regions for group A. In addition, an increased power in beta band frequencies was observed in both hemispheres for group A. Conclusion Increases in alpha band could be the hallmark of the 5Hz rTMS, but it could be reduced by escitalopram. Besides, increases observed in beta band for group A could be related to escitalopram effect.

La estimulación magnética transcraneal repetitiva (EMTr) es una técnica que permite estimular eléctricamente la corteza cerebral de manera no invasiva y con pocos efectos secundarios. Se ha propuesto que la EMTr aplicada sobre la corteza prefrontal dorsolateral (CPFDL) izquierda con frecuencias ≥5Hz tiene efectos antidepresivos. Se ha encontrado que en el electroencefalograma cuantitativo (QEEG por sus siglas en inglés) la mayoría de pacientes deprimidos presentan incrementos en las bandas theta y alfa, así como asimetrías interhemisféricas en la actividad alfa en regiones anteriores. La EMTr sobre la CPFDL izquierda a 5Hz ofrece ventajas considerables en seguridad y tolerabilidad; sin embargo, sus correlatos neurofisiológicos no han sido explorados por el análisis de fuentes del EEG. Objetivo Estudiar los cambios en las fuentes del EEG según el método VARETA en un grupo de pacientes con trastorno depresivo mayor que recibieron EMTr a 5Hz sobre la corteza prefrontal dorsolateral izquierda como tratamiento único o en combinación con escitalopram. Material y métodos Se estudiaron 18 pacientes con diagnóstico de trastorno depresivo mayor de acuerdo con los criterios del DSM-IV sin tratamiento para el episodio en curso. Los sujetos habían sido aleatoriamente asignados a uno de los siguientes grupos de tratamiento: A) EMTr+escitalopram 10mg, n=9; B) EMTr+placebo, n=9. Se aplicó EMTr, a 5Hz en una sesión diaria durante 15 días. Se obtuvieron dos registros electroencefalográficos, uno basal y otro final, con el fin de comparar los cambios en las fuentes de actividad eléctrica cerebral, pretratamiento y post-tratamiento. Se realizaron evaluaciones clinimétricas con las escalas de Hamilton para Depresión y Ansiedad y el Inventario de Depresión de Beck. Resultados Todos los pacientes en el grupo A y ocho pacientes en el grupo B respondieron al tratamiento, con una reducción de 50% o más en la escala HDRS. En el análisis de fuentes se encontró un efecto en el grupo B caracterizado por incremento en la PA de 9.37 a 10.17Hz, en regiones temporales y giro poscentral izquierdos, mismo que se encontró disminuido en el grupo A, Además se encontró un incremento en fracuencias correspondientes a la banda beta en regiones frontales de ambos hemisferios en el grupo A. Conclusiones Podría considerarse que el incremento en la banda alfa es característico de la EMTr a 5Hz, mismo que se ve reducido por efecto del escitalopram. Por otro lado, se observó que el grupo A mostró incrementos en fuentes correspondientes a la banda beta como posible efecto relacionado del fármaco antidepresivo.

Estandarización de la Figura de Taylor en población mexicana / Taylor's Figure Standardization on Mexican population

In order to perform a neuropsychologycal evaluation, the clinician may use several instruments; nevertheless, most of them have been designed for use on populations with very different social and cultural backgrounds from that of Mexico. This makes the research on the standardization of methods of evaluation for Mexican population a very important task for both clinical and research settings. Normative data obtained from Mexican population is necessary because it provides the clinician that works with Mexican patients with a reference framework that allows him or her to correctly classify a particular behavior of an individual as normal or abnormal and thus make specific evaluations and cooperate in diagnostic. Researchers interested on cognitive functioning also require qualitative and quantitative equivalent instruments that may allow them to objectively evaluate the efficacy of short-time interventions as in a pre- and post-treatment experimental designs; and it is precisely for this reason that Taylor's figure was developed. Taylor's figure (TF) was originally designed as an alternative to Rey-Osterrieth's complex figure (ROCF), in order to use it in test-retest situations. Similar to ROCF, Taylor's figure has two modalities: copy and memory. The former evaluates constructional praxia, while the latter measures immediate recalling. Parallel tests, that is, different tests that evaluate the same variables, are useful because they reduce the measurement error involved in applying the task twice to the same person (i.e. learning), thus increasing the validity of follow up evaluations of cognitive functioning. <

Dentro del ámbito neuropsicológico existe una serie de instrumentos de evaluación que en su mayoría han sido diseñados en un contexto sociocultural diferente al nuestro, por lo que es importante contar con pruebas neuropsicológicas estandarizadas en sujetos mexicanos. Desde esta perspectiva, los datos de una población normativa nos permiten tener un marco de referencia para comparar y establecer diagnósticos diferenciales dentro de la práctica clínica. Asimismo, dentro del ámbito de la investigación se requieren instrumentos que en teoría sean equivalentes en cuanto a la función que evalúan para llevar un seguimiento sobre el funcionamiento cognoscitivo de una población en particular a lo largo del tiempo. La Figura de Taylor se diseñó como una alternativa a la Figura Compleja de Rey-Osterrieth para aplicarla en situaciones de test-retest. Consta de dos modalidades: una de copia que evalúa la praxia de construcción y otra de memoria inmediata. El término <

Potenciales relacionados con eventos y comorbilidad en un grupo de adolescentes con trastorno por déficit de atención con hiperactividad / Event-related potentials and commorbidity in a group of teenagers with Attention Deficit Hiperactivity Disorder

Attention deficit hyperactivity disorder (ADHD) is a neuro-developmental disorder clinically characterized by three core symptoms: deficits in attentional processes, failure in inhibitory control -usually expressed through behavioral and cognitive impulsiveness-, and motor and verbal restlessness. Deficit in attentional resources is the main alteration in patients with this disorder. Attention can be considered as a neurocognitive state of neural preparation that precedes both perception and action. Attention focalizes consciousness in order to filter the constant flux of sensorial information, solve competence between stimuli for parallel processing and recruit and activate cerebral regions necessary to accomplish appropriate responses. Event-related potentials (ERPs) are a technique that has proven useful in the gathering of valuable information in the study of ADHD. One of the most studied ERPs is the P300 component. The most robust finding in the P300 research in ADHD is a decrease in the amplitude of the component in patients when compared to normal controls. This finding is usually interpreted as an evidence for a deficit in attention. ADHD usually presents commorbidity with several disorders; research shows that up to 87% of the children with ADHD present commorbidity with another disorder, up to 60% has either a behavioral or affective disorder commorbid with ADHD. Due to the wide range of disorders that are usually associated with this entity, it is useful in the research of commorbidity to use dimensional diagnostics, that is, a patient with ADHD may have commorbidity with an externalized disorder (EXT) (i.e. oppositionist defiant disorder); an internalized (INT) disorder (i.e. anxiety or affective disorder); or both an externalized and an internalized disorder (MIX). Commorbidity may have important implications in the electrophysiology of ADHD since no homogeneous results have been evident in the scarce research on the subject. Taking into account these considerations, the following experiment was designed in order to answer the question: Patients with the same main diagnostic, ADHD, but different commorbidities (INT and MIX) show different psychophysiological patterns of activation, as measured by ERPs to a continuous performance task? Sixteen patients diagnosed with ADHD by a specialist were recruited. Diagnosis was corroborated by a semi-structured interview, K-SADS-PL-MX, eight of them with an externalized comorbid (EXT) disorder, and eight of them with at least two comorbid disorders, one externalized an one internalized (MIX). A control group (CON) of eight normal subjects with no psychiatric diagnostic and matched by sex was also recruited. All subjects were between 13-16 years old with no history of Central Nervous System damage and normal IQ in the Weschler Intelligence Scale for Children. Brain electrical activity was recorded in the 19 derivations of the 10-20 international system while subjects executed a continuous performance task (CPT). Comparisons of behavioral data between groups showed some significant differences. A one-way ANOVA found differences between groups in the mean reaction time to the first part of the CPT and in the number of false positives in the second part. Electrophysiological data was analyzed with a non-parametrical multivariate test of permutations. When comparing responses to the frequent stimulus with responses to the infrequent, statistically significant differences were found in every subject; such differences share the topography and latency characteristics of the P3b component. When comparing the amplitude of this component between the groups, only two statistically significant differences were found. First, the EXT group presented a greater amplitude of the component elicited by the first part of the task in a latency of 425 to 445 msec in the parietal region of the medial line than the CON group. Second, also in response to the first part of the task, the amplitude of the CON group was bigger than that of the MIX group in a latency between 355 and 420 msec in the left temporal anterior region. No other comparison yielded significant results. When comparing between groups, mean reaction time to the first part of the task was the only behavioral variable that adequately distinguished control and patients. Even though controls executed significantly faster, they maintained the same efficacy as no differences were found in the number of errors or correct responses. This result is not surprising due to the fact that long reaction times usually denote inattention and so the fact that both groups of patients execute slower than the controls may be interpreted as a sign that, in spite of having different commorbidities, inattention is still a common problem in every patient of the sample. On the second part of the task, only the number of false positives showed statistically significant differences. However, in a posterior analysis of the data, it was evident that such differences were only between the EXT and the CON groups, with the EXT group presenting significantly more errors. False positives, especially on the second part of the task, are a measure of behavioral inhibition. Failure in inhibitory control is one of the three main symptoms of ADHD. However, some have proposed it as the main characteristic of the disorder. Analysis of the electrophysiological response to the first part of the task showed characteristic profiles of execution for each group. First, the P300 component was smaller in amplitude in the MIX group than in the control group and, even though differences were significant only in one derivation (T3), several other electrode sites more typically associated with the P300 component (C3, C4, P3, P4 and Pz) showed similar tendencies that did not reach statistical significance. Second, EXT patients had greater amplitude of the same P300 component in Pz than CON subjects. This result may seem to contradict most of the research on ADHD and P300. Nevertheless, considering the behavioral data, specially that no differences in correct responses were found between patients an controls, it is posible to assert that the greater amplitude of the component represents an overactive compensation in attentional circuits, necessary in the EXT group in order to execute at the same level of non-ADHD subjects. The results of this study present with information on a poorly reasearched subject: comorbidity and electrophysiology on ADHD.

La principal función afectada en el trastorno por déficit de atención con hiperactividad (TDAH) es la atención, la cual puede considerarse como un estado neurocognoscitivo cerebral de preparación que precede tanto a la percepción como a la acción. Los potenciales relacionados con eventos (PREs), una técnica útil en el estudio de la atención en esta entidad, pueden definirse como los cambios en la actividad eléctrica cerebral asociados temporalmente con la aparición de un evento, ya sea un estímulo o un proceso cognitivo. Con esta técnica es posible explorar las representaciones eléctricas de los procesos sensoriales y congnoscitivos con una alta resolución temporal. Uno de los PREs más estudiados en el TDAH es el P300, un componente positivo que ocurre en una latencia de alrededor de los 300 mseg. El hallazgo más contundente en el estudio del P300 en pacientes con TDAH es un decremento en la amplitud al compararlos con sujetos controles, lo cual suele ser interpretado como expresión de una atención deficiente. Por otro lado, el TDAH suele presentarse en comorbilidad con diferentes trastornos y siendo la presentación más infrecuente del síndrome es el TDAH <>. El presente estudio tiene como objetivo analizar si pacientes con el mismo diagnóstico principal, pero con diferente comorbilidad, presentan patrones de activación psicofisiológicos diferentes. Se evaluaron 16 pacientes diagnosticados con TDAH-M: ocho con comorbilidad EXT y ocho con comorbilidad MIX, así como ocho sujetos controles sanos. Tanto los pacientes como los controles realizaron las dos partes de una tarea de ejecución continua, mientras se registraba la actividad eléctrica cerebral en las 19 derivaciones del sistema internacional 10-20. En las medidas conductuales, las comparaciones intragrupos no arrrojaron diferencias estadísticamente significativas. Sin embargo, en las comparaciones entre grupos por medio de la prueba ANOVA de una vía sí aparecieron diferencias estadisticamente significativas (F=5.544 y p=0.012) entre los grupos en la media del tiempo de reacción en la parte 1 del CPT y en la variable errores por comisión en la parte 2 (F=3.975 y p=0.034). De las comparaciones electrofisiológicas realizadas entre grupos, sólo dos resultaron estadísticamente significativas. En primer lugar, el grupo EXT presentó mayor amplitud del componente que el grupo CON en una latencia entre 425-445 mseg en la región parietal media. En segundo lugar, el grupo CON tuvo mayor amplitud que el grupo MIX entre los 355-420 mseg en la región temporal anterior izquierda; ambos resultados se obtuvieron en la primera parte de la tarea. Ninguna otra comparación resultó significativa. Que el tiempo de reacción en la primera parte de la tarea fuera la única variable que distinguió entre pacientes y controles parece sugerir que, a pesar de que los pacientes tenían diferentes comorbilidades, la inatención sigue siendo el problema común a todos los pacientes de la muestra. La comparación de los datos electrofisiológicos entre grupos ofreció perfiles de ejecución característicos para cada subgrupo. Por un lado, el componente P300 fue de menor amplitud en los pacientes MIX que en los sujetos control (aunque sólo fue significativo en una derivación T3), lo cual concuerda con la bibliografía científica al respecto. Por otro, que los pacientes EXT presentaran mayor amplitud del componente P300 en Pz que los sujetos CON parece contrario a otros hallazgos de la bibliografía. Sin embargo, si se toma en cuenta que conductualmente tanto pacientes como controles ejecutaron al mismo nivel se puede sugerir que en los pacientes EXT el déficit de atención subyacente se compensa de manera exitosa y tal proceso se refleja en la amplitud de los PREs. Los resultados de este estudio proporcionan datos sobre cómo la comorbilidad incide en la respuesta electrofisiológica de los pacientes con TDAH.

Neuropsychological characterization in clinical subtypes of an Obsessive-Compulsive Disorder (OCD) sample of patients / Caracterización neuropsicológica en subtipos clínicos de una muestra de pacientes con Trastorno Obsesivo-compulsivo (TOC)

SUMMARY: Since the decade of the seventies, several neuropsychological abnormalities in very different cognitive domains have been described among patients with Obsessive-compulsive disorder (OCD). Due to the nature of these abnormalities, it was concluded that possibly the main dysfunction for this disorder was located in the right hemisphere, especially in the frontal cortex; nevertheless this particular brain region was found to be involved in other psychiatric disorders, so neuropsychological results were considered to be of limited precision and it was thought that the diversity in results was not due to the malfunction of one particular brain region. So it became evident that a new research methodology based in the information processing model with highly specific neuropsychological paradigms of frontal functioning was needed; as well as considering a subtypology based in the cognitive characteristics in patients with the same disorder and similar phenomenology. Regarding OCD it is well known that the dorsolateral prefrontal cortex is in charge of the regulation of complex actions, executive functions and the elaboration of logical strategies in a problem solving task; so its dysfunction causes a failure in the creation of response patterns and perseverations due to the inability to change a pattern when an alternative response is needed. On the other hand, obsessions are associated mainly with the anterior cingulated cortex and the basal region of the corpus striatum and its connections with the limbic system, giving place to incapacity to select the relevant information from the environment, which makes the individual perceive irrelevant stimuli as threatening for physical integrity. By the way, some clinical subtypes have also been identified: contamination/washing, aggressiveness/checking, hoarding, symmetry/ order. There is also some evidence of different patterns of brain activation to several visual stimuli related to the obsessive or compulsive object in the clinical subtypes, as shown by functional magnetic resonance image in some regions of the frontal lobe, either dorsolateral, medial or basal and its connections with the basal ganglia, and in some cases thalamus or limbic system. In the face of all this evidence, the goal of the present study was to find if within this disorder it was possible, through several neuropsychological paradigms of frontal functioning, to find different patterns of execution, considering the clinical subtype and the severity of obsessions and compulsions. Fifty-eight patients with a diagnosis of OCD were studied; all patients were under treatment at the OCD clinic of the National Institute of Psychiatry Ramón de la Fuente in Mexico City. Two neuropsychological tests were administered: 1) Trail Making Test (TMT) and 2) Wisconsin Card Sorting Test (WCST). From the Target Symptom List, the clinical subtype was obtained. After the statistical analysis, we found no differences between the severity of obsessions and the severity of compulsions as measured by the Yale-Brown Scale. Also, we observed three factors concerning the neuropsychological tests, and patients were grouped in four different groups, each one with a distinct cognitive performance. Through the interpretation of results it was concluded that in a sample of 58 patients with OCD, different groups of neuropsychological functioning where distinguished. In their own, these groups where associated with different clinical subtypes. These results are in accordance with the neurobiological modular organization model of OCD, which sustains the existence of independent systems of cognitive dysfunction that regulate different symptomatic expressions.

RESUMEN: La metodología de investigación, a partir del modelo del procesamiento de información con paradigmas neuropsicológicos de funcionamiento del lóbulo frontal, permite un estudio más específico de los trastornos psiquiátricos con fenomenología parecida, lo que a su vez permite crear modelos basados en una subtipología de índole cognoscitiva y, por ende, lleva al conocimiento de los circuitos neurales involucrados en la manifestación clínica de estos padecimientos. En el caso del trastorno obsesivo-compulsivo (TOC), la corteza prefrontal dorsolateral se encarga de regular las acciones complejas, las funciones ejecutivas y la elaboración de estrategias lógicas en la resolución de problemas, de tal manera que su mal funcionamiento ocasiona fallas en la creación de patrones de respuesta y perseveraciones por incapacidad de cambiar de patrón cuando se requiere otra alternativa de respuesta. Por otra parte, las obsesiones se relacionan predominantemente con el cíngulo anterior y la parte basal del cuerpo estriado y de sus conexiones con el sistema límbico, dando lugar a la incapacidad para seleccionar la información relevante del entorno. Esto genera que el individuo perciba los estímulos inocuos como "amenazantes" para la integridad física. También se han identificado subtipos clínicos de obsesiones y compulsiones, tales como contaminación, lavado, agresividad, comprobación, atesoramiento, simetría y de orden, entre otros, que se han relacionado con distintos patrones de transmisión genética, comorbilidad y respuesta a tratamiento. Además, se han documentado distintos patrones de aumento o disminución, ya sea de metabolismo cerebral o de flujo sanguíneo, en los circuitos fronto- estriados. Con la resonancia magnética funcional también se han encontrado distintos patrones de activación en los circuitos neuronales entre distintos subtipos clínicos, mediante la exposición de imágenes que se relacionan con el contenido de la obsesión o bien con la acción de la compulsión. Ante esta evidencia, se decidió averiguar si en pacientes con este trastorno era posible encontrar, mediante distintos paradigmas neuropsicológicos de funcionamiento frontal, dichos patrones diferenciales, considerando tanto el subtipo clínico como la gravedad de las obsesiones y compulsiones. En este estudio participaron 58 pacientes con este diagnóstico pertenecientes a la Clínica de TOC del Instituto Nacional de Psiquiatría Ramón de la Fuente, de los que 24 eran mujeres y 34, hombres. Una vez que los psiquiatras adscritos a dicha clínica confirmaban el diagnóstico obtenido en la cita de primera vez, referían a los pacientes al programa para computadora de Diagnóstico Neuropsicológico Automatizado (DIANA). Se aplicaron en una sola sesión las siguientes pruebas: 1) Trazado con Hitos (TH) y 2) Test de Categorización de Tarjetas de Wisconsin (TCTW). Con posterioridad a la aplicación de las pruebas a todos los pacientes, se revisó cada uno de los expedientes de la clínica de TOC para obtener el subtipo clínico. En el análisis estadístico de los datos se realizó primero un análisis factorial para disminuir el número de variables y luego un análisis de conglomerados para ver si se formaban grupos conforme a la ejecución de los sujetos en las pruebas aplicadas. De acuerdo con la ejecución de los pacientes se observó que los sujetos se agruparon en cuatro grupos distintos de desempeño cognoscitivo: el primero tuvo una ejecución muy deficiente en ambas pruebas. El segundo exhibió un desempeño regular en las dos pruebas pero fue mas rápido para terminar el TH. El tercero sólo estuvo constituido por dos pacientes que tuvieron un desempeño muy diferente al del resto, al presentar una ejecución sobresaliente en WCST pero con gran cantidad de errores en el TH. En tanto, en el cuarto de estos grupos, donde se concentraba la mayoría de la muestra, se consideró que su ejecución fue la más característica y su desempeño en ambas pruebas regular, pero más lento en TH. Cada uno de estos grupos de funcionamiento neuropsicológico se relacionó con los distintos subtipos de obsesiones y compulsiones, mas no con su gravedad. Encontrar subtipos neuropsicológicos de TOC asociados a sintomatología clínica distinta presta apoyo al modelo de organización modular de los diferentes circuitos neurales que intervienen en la manifestación sintomática de este padecimiento.