Journal of Behavior Therapy and Experimental Psychiatry 31 (2000) 55 } 66 Drinking away the hurt: the nature and prevalence of PTSD in substance abuse patients attending a community-based treatment program  Michel F. Bonin*, G. Ron Norton, Gordon J. G. Asmundson, Sandra Dicurzio, Shannon Pidlubney University of Winnipeg, Canada Regina Health District, Winnipeg, Manitoba, Canada Received 7 September 1999; received in revised form 17 February 2000; accepted 27 April 2000 Abstract The prevalence of posttraumatic stress disorder (PTSD) was evaluated in 91 participants attending a community-based substance abuse program. The participants were classi"ed as having PTSD, possible PTSD, or no PTSD using the modi"ed PTSD symptom scale (MPSS; Falsetti, Resnick, H. S., Resnick, P. A. & Kilpatrick, 1993). These groups were then compared on measures of anxiety, depression, and fear using the Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), Anxiety Sensitivity Index (ASI), and the Fear Questionnaire (FQ). The results showed that 52.8% of participants had either PTSD (37.4%) or possible PTSD (15.4%). Findings also showed that those with PTSD experienced more potentially traumatic events (e.g., rape, being beaten-up) compared to the possible PTSD and no PTSD participants. The PTSD group also reported signi"cantly greater scores on the ASI, BAI, and BDI than did the no PTSD group, and greater scores on the ASI and BAI than did the possible PTSD group. Further, when using a discriminant function analysis, self-report measures correctly classi"ed 70% of the PTSD group and 80% of a composite group of possible PTSD and no PTSD participants. Implications of these results are discussed.  2000 Published by Elsevier Science Ltd. Keywords: PTSD; Treatment; Substance abuse; Prevalence; Anxiety; Depression  Manuscript published under editorship of former editor L. Reyna. * Corresponding author. Tel.: 1-306-766-5451; fax: #1-306-766-5530. E-mail address: mbonin@reginahealth.sk.ca (M. F. Bonin). 0005-7916/00/$ - see front matter  2000 Published by Elsevier Science Ltd. PII: S 0 0 0 5 - 7 9 1 6 ( 0 0 ) 0 0 0 0 8 - 2