JMIR Publications

ABSTRACT

Background:

Eating disorders are psychological conditions characterized by unhealthy eating habits. Anorexia Nervosa (AN) is defined by the thought of being overweight despite being dangerously underweight. Psychological signs involve emotional and behavioral issues. There is evidence that signs and symptoms can be manifested on social media, where both harmful and beneficial content is shared daily.

Objective:

The aim of this work is to characterize Spanish speaking users with Anorexia signs on Twitter through the extraction and inference of behavioral, demographical, relational, and multi-modal data. This analysis is focused on characterizing and comparing users at different stages of the process to overcome the illness, including treatment and full recovery periods considering the Transtheoretical Model of Health Behavior Change (TTM).

Methods:

We analyze tweets published by users going through different stages of Anorexia. Users are characterized through their writings, posting patterns, relations, and images. We analyze the differences among users going through each stage of the illness and control users (users not suffering from AN). We also analyze the topics of interest of their followees (users followed by them). We perform a clustering approach to distinguish users at an early phase of the illness (precontemplation) from users that recognize that their behavior is problematic (contemplation); and generate models dedicated to the detection of tweets and images related to AN. We consider two types of control users: focused control users that use terms related to anorexia; and random control users.

Results:

We found significant differences between users at each stage of the recovery process (P<.001) and control groups. Users with AN tend to tweet more at night, with a median sleep period tweeting ratio of 0.05 in comparison to random control users (0.04) and focused control users (0.03). Pictures are relevant for the characterization of users. Focused and random control users are characterized by the usage of text on their profile pictures. We also found a strong polarization between focused control users, and users at the first stages of the disorder. There was a strong correlation (Spearman’s coefficient) among the shared interest between users with AN and their followees (0.96). Also, the interests of recovered users and users in treatment were more highly correlated to those corresponding to the focused control group (0.87 for both) in comparison to AN’s users (0.67), suggesting a shift on users’ interest during the recovery process.

Conclusions:

We have mapped signs of Anorexia Nervosa to the Social media context. These results enforce the findings of related work on other languages and involve a deep analysis on the topics of interest of users at each phase of the disorder. The features and patterns identified provide a basis for the development of detection tools and recommender systems.