Mental Illness

Preotiuc-Pietro, Daniel, Johannes Eichstaedt, Gregory Park, Maarten Sap, Laura Smith, Victoria Tobolsky, Andrew H. Schwartz, and Lyle Ungar. The Role of Personality, Age and Gender in Tweeting about Mental Illnesses In Workshop on Computational Linguistics and Clinical Psychology: From Linguistic Signal to Clinical Reality (CLPsych). NAACL, 2015. AbstractPDFSlides

Mental illnesses, such as depression and post traumatic stress disorder (PTSD), are highly underdiagnosed globally. Populations sharing similar demographics and personality traits are known to be more at risk than others. In this study, we characterise the language use of users disclosing their mental illness on Twitter. Language-derived personality and demographic estimates show surprisingly strong performance in distinguishing users that tweet a diagnosis of depression or PTSD from random controls, reaching an area under the receiver operating characteristic curve – AUC – of around .8 in all our binary classification tasks. In fact, when distinguishing users disclosing depression from those disclosing PTSD, the single feature of estimated age shows nearly as strong performance (AUC = .806) as using thousands of topics (AUC = .819) or tens of thousands of n-grams (AUC = .812). We also find that differential language analyses, controlled for demographics, recover many symptoms associated with the mental illnesses in the clinical literature.

Preotiuc-Pietro, Daniel, Maarten Sap, Andrew H. Schwartz, and Lyle Ungar. Mental Illness Detection at the World Well-Being Project for the CLPsych 2015 Shared Task In Workshop on Computational Linguistics and Clinical Psychology: From Linguistic Signal to Clinical Reality (CLPysch). NAACL, 2015. AbstractPDF

This article is a system description and report on the submission of the World Well-Being Project from the University of Pennsylvania in the `CLPsych 2015' shared task. The goal of the shared task was to automatically determine Twitter users who self-reported having one of two mental illnesses: post traumatic stress disorder (PTSD) and depression. Our system employs user metadata and textual features derived from Twitter posts. To reduce the feature space and avoid data sparsity, we consider several word clustering approaches. We explore the use of linear classifiers based on different feature sets as well as a combination use a linear ensemble. This method is agnostic of illness specific features, such as lists of medicines, thus making it readily applicable in other scenarios. Our approach ranked second in all tasks on average precision and showed best results at .1 false positive rates.