SUMMARYComparative study based on 565 adolescent school children coming from four schools in the metropolitan area of Santiago, Chile. All were interviewed in order to select a sample that was stratified for sex, class and condition of consumer or non-consumer. The variables of intellectual coefficient and socioeconomical level were maintained constant. With this selection we conformed two groups: 40 consumers exclusively of marihuana and 40 non-consumers. We compared the results obtained in both groups in the neuropsychological tests while the neuroSPECT studies of consumers were compared against a normal database for the same age group. The adolescent consumers of marihuana demonstrate less cognitive capacity related to the process of learning such as attention, concentration, ranking, viso-spatial integration, immediate retention and visual memory. The differences between both groups are statistically significant.The findings of neuroSPECT demonstrate subgenual hypoperfusion bilaterally, more marked on the left side, in area 25 of Brodmann. This area controls mood. There is also frontal bilateral hypoperfusion (area 10 and area 32 of Brodmann). Area 32 is pre-anterior cingulate gyrus. Also hypoperfusion of the anterior cingulate gyrus (area 24 of Brodmann) and hypoperfusion of area 36 of Brodmann that projects over the hippocampus.Students that were consumers exclusively of marihuana demonstrate coincident abnormal findings of neuroimages and neuropsychological tests in areas of the brain related with learning and also significant differences between consumers with non-consumers in the neuropsychological tests. Key words:Cannabis, marihuana, adolescent, SPECT, HMPAO, neuropsychological tests. RESUMENEstudio comparativo basado en 565 escolares adolescentes pertenecientes a cuatro colegios de Santiago, Chile. Fueron encuestados todos para seleccionar una muestra estratificada por sexo, curso y condición de consumidores o no consumidores, manteniendo constante las variables coeficiente intelectual y nivel socioeconómico. Se conforman dos grupos: 40 consumidores exclusivos de marihuana y 40 no consumidores. Se comparan los resultados obtenidos en ambos grupos en los Test Neuropsicológios y del NeuroSPECT de consumidores con una base de datos considerados normales para el mismo grupo etario.Los adolescentes consumidores de marihuana evidencian menores habilidades cognitivas asociadas al proceso de aprendizaje, tales como atención, concentración, jerarquización, integración visoespacial, retención inmediata y memoria visual. Las diferencias entre ambos grupos son estadísticamente significativas.Los hallazgos del NeuroSPECT muestran hipoperfusión subgenual bilateral, más marcada en el hemisferio izquierdo (área 25 de Brodmann), hipoperfusión frontal bilateral (areas 10 y 32 de Brodmann), hipoperfusión del gyrus cingulado anterior (área 24 de Brodmann) e hipoperfusión del área 36 de Brodmann que proyecta sobre el hipocampo.Los estudiantes consumidores exclusivamente de marihuana muestran compromiso coincidente en neu...

Este trabajo es una reflexión sobre nuestro tiempo y su vinculación con una manifestación clínica en aumento, cual es el fenómeno de las autolesiones. Se realizó un estudio focalizado por conveniencia a través de una entrevista clínica semiestructurada a 20 jóvenes que se generaban cortes en la piel, lo que incluyó variables de análisis relacionadas con: familia, identidad, función del síntoma y contexto. Los resultados revelaron que la conducta de autolesionarse se relacionaba con los cambios ocurridos en la sociedad occidental durante los últimos 50 años, tanto en lo relativo a la familia, como a la nueva forma de relacionarse a través de las redes sociales, en que primaría la comunicación virtual, masiva y anónima, por sobre la personal y real. Este hecho incidiría en la dificultad para consolidar una identidad, lo que se refleja en una imagen frágil e inestable de sí mismo, una dependencia del entorno aumentada, y serias dificultades para manejar y contener afectos de alta intensidad, llevándolo así a autolesionarse como forma de gestionar estas emociones. Finalmente, para enriquecer el análisis, se incorporaron las propuestas de la filosofía y sociología sobre las particularidades de nuestro tiempo, específicamente los aportes de Chul-Han, Luis Zoja, Zygmunt Bauman y James Côtè.

The study aims at knowing how low marijuana doses afect cognitive ability in postprimary students. The objective of the quantitative research was to analyze the results of neuropsychological and Neuro-SPECT tests comparing schoolchildren who smoke marijuana with those who do not, with emphasis on the efects on cognitive functions involved in learning. We wanted to assess the efects on the cerebral function of marijuana-only users. It was a comparative study based on the total sample of 565 school adolescents coming from four schools in the metropolitan area of Santiago, Chile. "ll were interviewed in order to select a sample that was stratiied by sex, class and consumption of marijuana. The following two groups were made: 40 marijuana-only users and 40 nonusers. We took as a reference a study performed by the authors in 2007, in which the correlation between the consumption of marijuana and efects on cognitive functions involved in scholastic learning were established. The indings show statistically signiicant diferences in the following areas: subgenual bilateral hypoperfusion, more marked on the left side "rodmann area 25 , frontal bilateral hypoperfusion "rodmann's areas 10 and 32 , front cingulate gyrushypoperfusion "rodmann area 24 and hypoperfusion of "rodmann area 36 that projects to the hippocampus. The results are highly matched with the neuropsychological tests given in the sense that, like with the 2007 study, signiicant diferences are found between the two groups as far as the tests measuring cognitive functions are concerned. " qualitative research: we wanted to investigate the experience of time in high school students who regularly smoke marijuana, given that this substance has efects on the prefrontal lobe and on the hippocampus, brain areas related to the ability to plan tasks executive function and to memory. Moreover, adolescence is a delicate stage in regard to planning of the future. "t the same time, the idea was to understand and make use of the concepts of temporariness and anticipation, which as a general rule will be handled only by philosophical theories. Our guiding principle is the ability to anticipate oneself, proposed by Suter, a phenomenological psychiatrist. Data were analyzed from the autobiographies of the students through the hermeneutical phenomenological method developed by Lindseth, based on Ricoeur. Results allow answering the question of the study about the temporary experiencing of the young abusive marijuana consumer. The results showed poverty in the temporary dimensions referring to the past and the future, while in the report, it is more developed in the present moment. They appear detained in a more childish stage, in which the present predominates, and the future seemed not to be united with the past, which impresses as if it were avoided. What has been past does not link with what is wanted to be, so, elements of the past have no relation with future project.

This article is a reflection on the current affairs and an invitation to think about worrying phenomena in youngsters: self-injuries or cuts in the arms in eight young adolescent patients. We try to figure out the underlying cause of such behavior, which is more common every day and reveals some characteristics of society. Sociocultural, individual and family changes are analyzed, showing possible connections among these instances, identity and self-injuries. We suggest that the difficulties in identity development may be related to practices such as self-injury or others, which are related to mentalization problems. In the sociocultural level we find a way to socialize in which subjective discomfort has increased, there is overabundance, mass consumption, and the traditional social institutions (family, school and religion) have failed. Youngsters do not know themselves nor their projects. This difficulty is accompanied by an individual's failure in mentalization capacities (name one's feelings), leading the suffering youngster to practices such as self-injuries, which become permanent. Finally, the particulars of family relationships are described: distance between parents and their offspring, with the life experiences of the former being less appreciated by their offspring while forming their own identity, this is, they are responsible of becoming the architects of their own identities. They are orphans without traditions, which are sources of identity and innovation; to know who we are we must know where we come from.Disclosure of interestThe authors have not supplied their declaration of competing interest.