Social network sites use, body image disturbance and other psychological correlates during the COVID-19 pandemic

[eng] This thesis aimed (1) to validate the Physical Appearance Comparison Scale-Revised (PACS-R) in a Spanish sample, (2) to examine the levels of depression, anxiety, stress, self-esteem, disordered eating, body dissatisfaction and drive for thinness during the first months of the COVID-19 pandemic, (3) to explore the changes in SNSs use, body dissatisfaction and appearance comparisons during the pandemic, (4) to determine whether Instagram use (frequency of use and appearance-focused use) was associated with body image disturbance and low self-esteem during the initial months of the pandemic, and (5) to explore whether there was a relationship between the changes in Instagram use throughout the pandemic and body dissatisfaction and appearance comparisons. Four studies were conducted. The first three studies had a cross-sectional design and the fourth one a longitudinal design. The first study, which aimed to validate the Spanish PACS-R, involved 1405 participants aged 14-64, who completed the PACS-R along with measures of body image, eating disturbances, appearance-related sociocultural influences, self-esteem, and social comparison. The second and third studies were conducted during the initial months of the pandemic and aimed to examine the levels of emotional distress and disordered eating, to assess SNSs use, body image disturbance and self-esteem, and to explore whether SNSs use was associated with body image disturbance and low self-esteem. A total of 2847 individuals aged 14-35 participated in the second study, and 2601 women aged 14-35 participated in Study 3. The fourth study aimed to determine the evolution of Instagram use, body dissatisfaction and appearance comparisons throughout the pandemic, and involved 272 Spanish women (16-70 years old) that were followed-up across four waves of assessment (November 2019-July 2021). The main findings of the thesis were the following ones: (1) the Spanish PACS-R has excellent psychometric properties; (2) severe levels of depression, anxiety and stress were found in around one quarter of the sample during the initial months of the pandemic; (3) lockdown was associated with several perceived changes in different life domains; (4) following appearance-focused accounts on Instagram and a higher frequency of use of Instagram significantly predicted higher levels of drive for thinness during the initial months of the pandemic; (5) the frequency of use of SNSs and the number of women following appearance-focus