A Deep Transfer Learning Approach for Improved Post-Traumatic Stress Disorder Diagnosis

Post-traumatic stress disorder (PTSD) is a traumatic-stressor related disorder developed by exposure to a traumatic or adverse environmental event that caused serious harm or injury. Structured interview is the only widely accepted clinical practice for PTSD diagnosis but suffers from several limitations including the stigma associated with the disease. Diagnosis of PTSD patients by analyzing speech signals has been investigated as an alternative since recent years, where speech signals are processed to extract frequency features and these features are then fed into a classification model for PTSD diagnosis. In this paper, we developed a deep belief network (DBN) model combined with a transfer learning (TL) strategy for PTSD diagnosis. We computed three categories of speech features and utilized the DBN model to fuse these features. The TL strategy was utilized to transfer knowledge learned from a large speech recognition database, TIMIT, for PTSD detection where PTSD patient data is difficult to collect. We evaluated the proposed methods on two PTSD speech databases, each of which consists of audio recordings from 26 patients. We compared the proposed methods with other popular methods and showed that the state-of-the-art support vector machine (SVM) classifier only achieved an accuracy of 57.68%, and TL strategy boosted the performance of the DBN from 61.53% to 74.99%. Altogether, our method provides a pragmatic and promising tool for PTSD diagnosis.

I. Introduction

PTSD is a traumatic-stressor related disorder. It develops after a person is exposed to a traumatic or an adverse environmental event that caused serious harm or injury. Examples of such events may include torture, severe war zone stress and others. Symptoms of PTSD patients may include interference with normal social, occupational functioning and depression. PTSD is a serious problem for military, affecting 30% of military service members who have spent time on war zones which makes it an emerging issue to be resolved. Today, PTSD is recognized as a psychobiological mental disorder that can affect survivors of combat experience, terrorist attacks, natural disasters, serious accidents, assaults, abuses and sudden major emotional losses.