Negation detection NLP tool. If you use the code, please cite George Gkotsis, Sumithra Velupillai, Anika Oellrich, Harry Dean, Maria Liakata and Rina Dutta. Don't Let Notes Be Misunderstood: A Negation Detection Method for Assessing Risk of Suicide in Mental Health Records, Computational Linguistics and Clinical Psychology 2016 - View it on GitHub