During the last two years the COVID-19 pandemic has affected the world population in several ways. An important increase in mental health problems is a consequence of this pandemic that is ubiquitous worldwide. In this work we study the effect of the pandemic on the mental health of a population of teenagers and youth based on the analysis of natural language processing, machine learning algorithms and expert knowledge. The data analysed was obtained from a chat helpline called Safe time from theIt Get’s Better Foundation in Chile. The data consists of 10,986 conversations gathered from 2018 until 2020 between volunteers from the foundation and users of the platform. We compared the conversationsbefore and during the pandemic in terms of their thematic content. Our analysis found: a significantdecrease in self-image appreciation during the pandemic; a significant decrease in the quality of personalrelationships during the pandemic, and a significant increase of performance appreciation.

En el presente artículo se discuten diversas cuestiones relativas a la plataforma de intercambio de vídeos YouTube. Uno de los hallazgos más relevantes de esta investigación es la evidente tendencia de sus usuarios a utilizar el servicio como vehículo para la expresión de su propia identidad. El sentimiento de comunidad, así como el notable dinamismo del sistema a la hora de generar fenómenos sociales novedosos, invitan a la reflexión sobre el papel que puede jugar este tipo de plataformas en la incipiente Sociedad del Conocimiento. El artículo concluye con una valoración general del fenómeno y un llamamiento a acometer su estudio con una mayor profundidad.