Approximate Nearest Neighbour Extraction Techniques and Neural Networks for Suicide Risk Prediction in the CLPsych 2022 Shared Task

This paper describes the participation of our group on the CLPsych 2022 shared task.For task A, which tries to capture changes in mood over time, we have applied an Approximate Nearest Neighbour (ANN) extraction technique with the aim of relabelling the user messages according to their proximity, based on the representation of these messages in a vector space. Regarding the subtask B, we have used the output of the subtask A to train a Recurrent Neural Network (RNN) to predict the risk of suicide at the user level.The results obtained are very competitive considering that our team was one of the few that made use of the organisers proposed virtual environment and also made use of the Task A output to predict the Task B results.