[State of mind in adolescents in Barcelona province (Spain): Evolution, associated factors and impact of the pandemic.]

Objective: To analyse the evolution of state of mind in adolescents in the province of Barcelona for the last six years and the specific impact of the pandemic and its experience. Likewise, analyse the associated factors both in pre-pandemic period and during.

Methods: Since 2015/2016 a Questionnaire on health related habits was carried out among 4^th year high school students to which a COVID-19 chapter was added in the 2020/2021 academic year. There was a representative provincial pre-pandemic sample (N=15,118) and a sample during the pandemic (N=4,966). The dichotomous aggregate variable of positive/negative state of mind was constructed with six specific items to which the bivariate analyses and a multivariate generalized mixed linear model were carried out for both periods. Analysis performed with SAS.

Results: The pandemic significantly intensified the trend of worsening the state of mind adolescents, and widened the gender gap. Boys went from 17.9% (pre-pandemic) to 25.7% (during pandemic) with a negative mood, while girls from 31.9% to 52.9%. In modelling during pandemic, socioeconomic and family factors appeared relevant and significant. Sex, perceived poor health, being victim of harassment, self-perception of weight, excessive use of the internet and a poor perception of the residential environment remained significant as in the pre-pandemic model.

Conclusions: The specific negative impact of the pandemic on adolescents' mental well-being is perceived, but it is too early to tell whether it is reversible or not and to assess the effectiveness of interventions to tackle it.