Research of language use in authors affected by mental disorders is geared toward a deeper understanding of mental health and the development of models for early detection of various disorders. In this talk, the focus will be on Reddit dataset with thousands of users suffering from 9 different mental illnesses. I will talk about adapting deep learning models for long-length text classification to predicting mental state of a user in social media. I will also present some preliminary feature analysis, problems in this interdisciplinary field, and ideas for future work.