Drug and Alcohol Dependence 77 (2005) 251–258 Co-morbid post-traumatic stress disorder in a substance misusing clinical population Martina Reynolds a,∗ , Gillian Mezey b , Murray Chapman c , Mike Wheeler b , Colin Drummond d , Alex Baldacchino e a School of Social Sciences and Law, Brunel University, Uxbridge, Middlesex, UB8 3PH, UK b Section of Forensic Psychiatry, Department of Psychiatry, St George’s Hospital Medical School, London, UK c North West Mental Health Service, Broome, WA, Australia d Department of Addictive Behaviour and Psychological Medicine, St George’s Hospital Medical School, London, UK e Department of Psychiatry, Centre for Addiction Research and Education, Ninewells Hospital Medical School, University of Dundee, UK Received 20 January 2004; received in revised form 28 July 2004; accepted 17 August 2004 Abstract Background: USA studies have reported high rates of co-morbid post-traumatic stress disorder (PTSD) and substance (drugs and alcohol) dependence/misuse. Avoidance of trauma reminders and associated distress may be achieved by the use of drugs and alcohol, alternatively a substance abusing lifestyle might predispose such individuals to experience traumatic events. This may have implications for treatment and management of patients with co-morbid substance misuse and PTSD. There have been no British studies looking at the extent of traumatic life events and post-traumatic stress disorder amongst substance misusers, although high rates of reported sexual and physical abuse have been reported in two recent UK studies with drug- and alcohol-dependent patients in clinical settings. Aims: (i) To investigate the prevalence of co-morbid PTSD in a UK substance use disorder (SUD) inpatient clinical population; (ii) to identify the characteristics, severity and types of trauma experienced; (iii) to compare SUD patients with and without co-morbid PTSD on substance use and history, psychological/psychiatric and social variables Method: This is a cross-sectional study involving interviews with patients and case note review. SUD inpatients were interviewed about traumatic experiences, PTSD, and addiction. Results: Ninety-four percentage reported experiencing one or more PTSD criterion A traumatic experiences. 38.5% met criteria for current PTSD and 51.9% for lifetime PTSD. Significant differences between the PTSD and non-PTSD groups were found in PTSD and trauma-related variables, notably social variables and distress associated with traumatic experiences, but few differences were found in addiction severity (medical and psychiatric composite scores of the ASI) and psychiatric symptomatology. Conclusions: This study highlights not only the importance of assessment of trauma and PTSD amongst substance misusers but, conversely the need for the assessment of substance abuse among victims of PTSD. Co-morbid psychopathology is common, so trauma histories and PTSD symptoms may become embedded in other co-morbid psychopathology. © 2004 Elsevier Ireland Ltd. All rights reserved. Keywords: Co-morbidity; PTSD; Substance use disorder 1. Introduction Substance misuse is associated with a range of physical, psychological and social problems, which affect individuals ∗ Corresponding author. Tel.: +0044 1895 274000. E-mail address: martina.reynolds@brunel.ac.uk (M. Reynolds). and their families and communities. These include physi- cal health problems, psychological problems, social prob- lems and crime (Gossop et al., 1998a,b). Although treat- ment may result in significant improvement in a range of outcomes including drug use, physical and psychological health and criminal behaviour, relapse rates in substance abuse populations are relatively high (Gossop et al., 1998a,b; 0376-8716/$ – see front matter © 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.drugalcdep.2004.08.017