Substance Use Attenuates Physiological Responses Associated With PTSD among Individuals with Co-Morbid PTSD and SUDS
- Corresponding Author:
- Tanja Jovanovic
Department of Psychiatry & Behavioral Sciences Emory University School of Medicine
49 Jesse Hill Jr. Dr., Suite 331, Atlanta, GA 30303, USA
Fax: 404-778-1488 E-mail: [email protected]
Received date: July 08, 2013; Accepted date: August 26, 2013; Published date: August 30, 2013
Citation: Davis TA, Jovanovic T, Norrholm SD, Glover EM, Swanson M, et al. (2013) Substance Use Attenuates Physiological Responses Associated With PTSD among Individuals with Co-Morbid PTSD and Suds. J Psychol Psychother S7:006. doi:10.4172/2161-0487.S7-006
Copyright: © 2013 Davis TA et al., This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Posttraumatic stress disorder (PTSD) is often conceptualized from a fear conditioning perspective given individuals with PTSD demonstrate a reduced ability to inhibit fear even under safe conditions as compared to those without PTSD. The self-medication hypothesis suggests that individuals with PTSD often develop substance use disorders (SUDs) as an attempt to mitigate trauma-related distressing emotions. This investigation examined this hypothesis in a sample 214 participants, of which 81 did not meet criteria for either PTSD or SUDs (No diagnosis Control group); 33 met criteria for lifetime PTSD, but not SUDs (PTSD only group); 54 met criteria for lifetime SUDs, but not PTSD (SUDs only group); and 46 met lifetime criteria for both disorders (PTSD+SUDs group). PTSD was assessed using the modified PTSD Symptoms Scale (mPSS), and SUDs were assessed using the Structured Clinical Interview for DSM-IV (SCID). The startle magnitude was assessed using electromyography (EMG) of the eyeblink muscle in response to an acoustic startle probe. Fear-potentiated startle (FPS) was analyzed by comparing startle magnitude at baseline to startle during a fear conditioned stimulus. Results showed that PTSD significantly increased startle responses. However, there was a significant effect of SUDs on fear-potentiated startle to the danger signal, in that those who met criteria for SUDs had reduced fear compared to those who did not. The individuals who had co-morbid PTSD and SUDs did not differ from the Control group. Findings indicate that SUDs may attenuate exaggerated fear responses associated with PTSD. Consistent with the self-medication hypothesis, results suggest that substance use may co-occur with PTSD because it reduces heightened fear load and may allow normalized function in traumatized individuals.