“…Written text carries implicit information about the author, a relationship that has been exploited in natural language processing (NLP) to predict author characteristics, such as age (Goswami et al, 2009;Rosenthal and McKeown, 2011;Nguyen et al, 2011;Nguyen et al, 2014), gender (Sarawgi et al, 2011;Ciot et al, 2013;Liu and Ruths, 2013;Alowibdi et al, 2013;Volkova et al, 2015;Hovy, 2015), personality and stance (Schwartz et al, 2013b;Schwartz et al, 2013a;Volkova et al, 2014;Plank and Hovy, 2015;Preoţiuc-Pietro et al, 2015), or occupation (Preotiuc-Pietro et al, 2015a;Preoţiuc-Pietro et al, 2015b). The same signal has also been effectively used to predict mental health conditions, such as depression (Coppersmith et al, 2015b;Schwartz et al, 2014), suicidal ideation (Coppersmith et al, 2016;Huang et al, 2015), schizophrenia (Mitchell et al, 2015) or post-traumatic stress disorder (PTSD) (Pedersen, 2015), often more accurately than by traditional diagnoses.…”