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Violent traumatic events and drug abuse severity
Journal of Substance Abuse Treatment 20 (2001) 121 ± 127
Regular article
Violent traumatic events and drug abuse severity H. Westley Clark, M.D., J.D.a,b,*, Carmen L. Masson, Ph.D.a, Kevin L. Delucchi, Ph.D.a, Sharon M. Hall, Ph.D.a, Karen L. Sees, D.O.a,b a
Department of Psychiatry, Langley Porter Psychiatric Institute, University of California-San Francisco, 401 Parnassus Avenue, San Francisco, CA 94143, USA b Department of Psychiatry, San Francisco Veterans Affairs Medical Center, 4150 Clement Street, San Francisco, CA 94121, USA Received 19 April 1999; received in revised form 17 July 2000; accepted 25 August 2000
Abstract We examined the occurrence of violent traumatic events, DSM-III-R diagnosis of posttraumatic stress disorder (PTSD), and PTSD symptoms, and the relationship of these variables to drug abuse severity. One-hundred fifty opioid-dependent drug abusers who were participants in a randomized trial of two methadone treatment interventions were interviewed using the Diagnostic Interview Schedule, the Addiction Severity Index, and the Beck Depression Inventory. Twenty-nine percent met diagnostic criteria for PTSD. With the exception of rape, no gender differences in the prevalence of violent traumatic events were observed. The occurrence of PTSD-related symptoms was associated with greater drug abuse severity after controlling for gender, depression, and lifetime diagnosis of PTSD. The high rate of PTSD among these methadone patients, the nature of the traumatic events to which they are exposed, and subsequent violence-related psychiatric sequelae have important implications for identification and treatment of PTSD among those seeking drug abuse treatment. D 2001 Elsevier Science Inc. All rights reserved. Keywords: Posttraumatic stress disorder; Depression; Drug abuse severity; Violence
1. Introduction Hard drug users (e.g., opioid users, cocaine users) are at high risk for experiencing violence, but the nature of the traumatic events that lead to the development of Posttraumatic Stress Disorder (PTSD) among drug users, and their association with drug use severity, is not completely understood. Among victims of crime, experiencing events that are perceived as life-threatening (e.g., rape and physical assault) is associated with the development of PTSD and other psychiatric disorders (Kilpatrick et al., 1989; Resnick, Kilpatrick, Dansky, Saunders, & Best, 1993). Also, individuals exposed to violent traumatic events may be at increased risk of substance abuse and depressive symptoms (Kilpatrick et al., 1989; Villagomez, Meyer, Lin, & Brown, 1995). These associations are relevant for the treatment of substance abuse because untreated PTSD and psychiatric * Corresponding author. SAMHSA/CSAT, Rockwall II, Suite 615, 5600 Fishers Lane, Rockville, MD 20857, USA. Tel.: +1-301-443-5700; fax: +1-301-443-8751. E-mail address: [email protected] (H.W. Clark).
comorbidities may lead to poor treatment outcomes (Brady, Killeen, Saladin, Dansky, & Becker, 1994; Brown, Stout, & Mueller, 1996; Root, 1989). A greater understanding of the extent to which violence-related PTSD and psychiatric comorbidities contribute to increased substance use and to relapse after drug abuse treatment may assist in the development of treatment strategies for this high-risk group. This study examined the relationship among violent traumatic events, PTSD, and the severity of drug abuse. There is a strong association between violent assault, PTSD, and drug abuse (Breslau, Davis, Andreski, & Peterson, 1991; Fullilove et al., 1993; Kessler, Sonnega, Bromet, Hughes, & Nelson, 1995). In a general population study, Cottler, Compton, Mager, Spitznagel, and Janca (1992) found that opioid and cocaine abusers were three times more likely to meet DSM-III diagnostic criteria for PTSD, compared to individuals without a substance use disorder. Substance abusers were also more likely to report physical assault as the precipitating traumatic event leading to PTSD (Cottler et al., 1992). In one of the few studies examining the association of violent traumatic events and PTSD among patients presenting for methadone treatment, Villagomez et
0740-5472/01/$ ± see front matter D 2001 Elsevier Science Inc. All rights reserved. PII: S 0 7 4 0 - 5 4 7 2 ( 0 0 ) 0 0 1 5 6 - 2
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al. (1995) reported that 14.2% of the sample met diagnostic criteria for PTSD. Estimates of PTSD in general population samples have ranged from approximately 1% to 9%, which is substantially lower than rates reported in studies of drug abusers (Breslau et al., 1991; Dansky et al., 1996; Helzer, Robins, & McEvoy, 1987; Kessler et al., 1995; Wasserman, Havassy, & Boles, 1997). Investigations of PTSD among drug abusers reveal a high prevalence rate of depressive symptoms and diagnoses (Najavits et al., 1998; Villagomez et al., 1995; Wasserman et al., 1997). Villagomez et al. (1995) reported that opioiddependent patients who met diagnostic criteria for PTSD at some point in their life were more likely than those without PTSD to experience depression and suicidal thoughts, and to make suicide attempts (see also Najavits, Weiss, Shaw, & Muenz, 1998; Wasserman et al., 1997). A history of violent trauma is also associated with more severe drug use, and riskier drug use and sexual behaviors (Miller et al., 1995; Paone, Miller, & Friedman, 1995). Understanding the extent to which violence-related PTSD and co-occurring depression may contribute to increased substance use is important, because these risk factors can be ameliorated by treatment (Najavits, 1997). The central objective of the present study was to assess the extent to which violent traumatic events, PTSD, and recency of PTSD-related symptoms contribute to drug use severity above and beyond the contribution of depressive symptomatology in methadone treatment patients. It is hypothesized that exposure to violent traumatic events will affect drug abuse severity over time in one of two ways: (a) recent experience of PTSD symptoms may lead to increased drug use or (b) untreated PTSD and psychiatric sequelae may take time to exert their effects on drug abuse severity in which drug use progressively increases over time. Knowledge about the recency of traumatic events exposure and PTSD symptoms may have important implications for the development of treatment interventions for those with cooccurring PTSD and drug abuse disorders. 2. Method 2.1. Participants Participants were the first 150 patients (59 women, 91 men) enrolled in a randomized, clinical trial comparing long-term (180-day) methadone detoxification plus an intensive psychosocial treatment versus methadone maintenance with a standard psychosocial treatment (Sees et al., 2000). Potential participants were evaluated for appropriateness for methadone treatment based upon physical examination, medical history, and indicated laboratory findings. Participants provided an observed urine sample that was tested for the presence of opioids. All participants were required to meet the following inclusion criteria: (1) DSM-III-R diagnosis of opioid dependence and (2) initial urine toxicology
screen positive for an opioid other than methadone and negative for methadone. In addition, the following exclusion criteria were applied: (1) any acute medical illness which contraindicated initiating methadone treatment (e.g., acute hepatitis); (2) inaccessible veins for venipuncture; (3) current enrollment in substance abuse treatment elsewhere; (4) enrollment in a methadone treatment program within the previous seven days or in the follow-up phase from a previous methadone detoxification research protocol; (5) not expected to remain available in the study for 12 months; and (6) no evidence of opioid withdrawal to start on methadone (i.e., three attempts). If participants met criteria for inclusion in the study, they read and signed a copy of the university-review-board-approved consent form. The University of California, San Francisco, Committee on Human Research approved the study. Patients were predominantly Caucasian (52.6%), male (61%), never married (38%), and unemployed (50%). The mean age was 43.7 years (SD = 2.38). Most had histories of arrests or convictions (67.3%), but no current legal restraints, were not homeless (97.3%), and had a high school education or less (mean years of education = 11.9). A majority reported prior drug abuse treatment (139 out of 150; 93%). Approximately 85% met DSM-III-R criteria for severe heroin dependence, 14% for moderate dependence, and less than 1% for mild dependence. 3. Measures The measures examined in the current study were part of a larger battery of questionnaires administered in the clinical trial. Participants were interviewed at baseline and monthly for 12 months. Information on demographic characteristics, substance use, and psychiatric diagnoses and symptoms was obtained at treatment entry and all subsequent analyses are based on this baseline data. The Computerized Diagnostic Interview Schedule (CDIS) was used to assess substance use and psychiatric disorders as defined by DSM-III-R (Robbins et al., 1981; Levitan et al., 1991). The sections on substance use disorders, Posttraumatic Stress Disorder, Depression, and Dysthymia are included in this report. For each disorder, participants were given a diagnosis of PTSD if they met full diagnostic criteria at some point in their life. The recency of PTSD-related symptoms associated with each traumatic event was rated on a six-point scale: (1) within the last two weeks; (2) two weeks to less than a month ago; (3) one month to less than six months ago; (4) six months to less than a year ago; (5) sometime in the last twelve months; and (6) more than one year ago. The Beck Depression Inventory (BDI) (Beck, Ward, Mendelsohn, Mock, & Erbaugh, 1961) is a 21-item questionnaire designed to assess level of depressive symptoms. This instrument has been successfully used to screen depression in a variety of psychiatric and normal
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populations, including substance abusers (Beck, Steer, & Garbin, 1989). The Addiction Severity Index (ASI) (McLellan, Alterman, Cacciola, Metzger, & O'Brien, 1992) is a structured clinical interview that assesses current and lifetime drug and alcohol use. It provides severity ratings and composite scores in seven functional areas (medical, alcohol, drug, legal, social, employment, and psychological) commonly impaired among substance abusers. This instrument has been demonstrated to have acceptable levels of reliability and validity with several substance-abusing populations (McLellan et al., 1992; Zanis, McLellan, Cnaan, & Randall, 1994). 3.1. Procedure Participants who met eligibility criteria, gave informed consent, and completed the intake procedures were randomized to either long-term (180-day) methadone detoxification or methadone maintenance at the time that they presented in opioid withdrawal. The demographics questionnaire and standardized measures were administered before the participant was assigned to either treatment condition and received the first methadone dose. C-DIS questions were read aloud to participants. The C-DIS computer-scoring program was used to generate diagnoses and current PTSD-related symptoms. For each psychiatric disorder identified by the C-DIS, participants were given a diagnosis if they met full diagnostic criteria at any time in their life. Current PTSD-related symptoms were defined as having at least one symptom of the disorder in the past 6 months, once having met the full diagnostic criteria for PTSD, on the basis of DSM-III-R criteria. 3.2. Statistical analyses Analyses were conducted to estimate the rates of PTSD, violent traumatic events, and depression in this sample of methadone patients and to examine gender differences in the occurrence of violent traumatic events. Descriptive statistics were used to summarize sociodemographic and substance use characteristics of the sample. Groups were compared using independent t-tests or ANOVA for the continuous measures and chi-square tests for the categorical. In addition, separate logistic regression models were used to test the effects of PTSD status and gender on each of the three Table 1 Distribution of violent traumatic events by gender Women (n = 59)
Men (n = 91)
Events
No. of events
%
No. of events
%
Rape Seeing someone hurt/killed Physical assault Total
24 20 8 52
46.1 38.5 15.4 100.0
2 34 27 63
3.2 54.0 42.8 100.0
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types of violent traumatic events experienced (i.e., rape, physical assault, and seeing someone hurt or killed; see Table 1). Finally, a hierarchical multiple regression analysis was conducted to determine the relationship of history of PTSD, recency of PTSD symptoms, and the type of violent traumatic event to drug use severity. 4. Results 4.1. Demographic and drug use characteristics There were no significant differences between the groups with and without PTSD for any sociodemographic characteristics with the exception of marital status. Participants who did not meet DSM-III-R criteria for PTSD were more likely to never have been married, c2 (4) = 11.94, p = 0.016. In addition, there were no significant differences between men and women in the diagnosis of mild/moderate (14% vs. 15%) versus severe (86% vs. 85%) heroin dependence, P2 (1) = 0.03, n.s. 4.2. Diagnosis of posttraumatic stress disorder Of the 150 patients, 44 (29%) were classified as having had a DSM-III-R diagnosis of PTSD at some point in their life. A significantly higher percentage of women (53%; 31 out of 59) than men (14%; 13 out of 91) met diagnostic criteria for PTSD, c2 (1) = 25.27, p < 0.001. Fifty-five percent of the participants who had a history of PTSD also reported PTSD-related symptoms in the past 6 months. 4.3. Exposure to traumatic events A total of 219 traumatic events as defined by the DSMIII-R were reported by 108 of the patients (M = 2.0 events per participant). Seventy-two percent of the sample reported exposure to at least one traumatic event. Those meeting diagnostic criteria for PTSD reported a greater total number of traumatic events (M = 2.2, SD = 0.88 vs. M = 1.15, SD = 1.14, t (103) = 6.11, p < 0.001, than those who did not meet diagnostic criteria for the disorder. The C-DIS limits respondents' reporting to a maximum of three traumatic events. Therefore, for each of the three main traumatic events of interest (rape, physical assault, and seeing someone hurt or killed), the total number of reported occurrences was limited to three. Because only a small percentage of the sample experienced more than one of each of these (28 out of 150; 19%), we dichotomized the violent traumatic events of rape, physical assault, and seeing someone hurt or killed to examine differences between those who had or had not experienced such an event. Three separate logistic regression models were used to test the relationship between each of the three violent traumatic events and PTSD status, gender, and their interaction. The model predicting occurrence of rape versus not was not
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statistically significant ( ÿ 2Log Likelihood c2 (3) = 33.6, p = 0.001). Of the individual Wald c2 tests for each parameter, only the one for gender was significant ( p = 0.0031), with women more likely to experience rape than men. No independent associations were identified for physical assault or seeing someone hurt or killed. 4.4. PTSD status, depression, dysthymia, and suicide attempts Those with a history of PTSD also reported a history of depression, dysthymia, and suicide attempts. Participants with a history of PTSD were also more likely to be diagnosed with depression: 46% (20 out of 44) as compared with 14% (15 out of 106) of those who had not had PTSD, c2 (1) = 17.03, p < 0.001. Similarly, those diagnosed with PTSD (9 out of 44, 21%) were more likely to be diagnosed with dysthymia than those without a history of PTSD (7 of 106, 7%; c2 (1) = 6.26, p < 0.05). PTSD was also associated with suicide attempts among those who had experienced PTSD at some point in their life (64%, 16 out of 25) than among those without such a history: 36% (9 of 25), P2 (1) = 17.15, p < 0.001. These results suggest that methadone maintenance patients with PTSD are more likely to have comorbid disorders than those without. Corroborating evidence of psychiatric comorbidity between PTSD and depressive disorders was estimated with the BDI. A 2 2 ANOVA of BDI scores revealed a significant main effect for PTSD status, with higher BDI scores among participants with PTSD as compared to those without PTSD, F (1,140) = 3.76, p < 0.05. There was no main effect of gender [F (1,140) = 2.11, n.s.], nor did PTSD status interact with gender [F (1,140) = 1.39, n.s.]. 4.5. PTSD diagnosis and symptoms, types of traumatic events, and ASI drug use severity A hierarchical multiple regression analysis was estimated and tested to examine the effects of history of PTSD diagnosis, recency of PTSD symptoms, and the type of traumatic event on the severity of drug use (as measured by the ASI). Gender and BDI scores, which are known to be related to drug use severity, were first entered into the model. Because psychological distress is a risk factor for substance use and may produce vulnerability to greater drug use severity, diagnosis of PTSD was entered in step 3 before recency of PTSD-related symptoms and the types of traumatic events leading to PTSD. PTSD status did not have a significant effect on drug use severity, F < 1, once gender and depression were already in the model. Recency of PTSD symptoms was entered in the fourth step and produced a significant increase in the prediction of drug use severity scores, R2 change = 0.09, F (1,74) = 7.94, p < 0.01. These findings suggest that past experience of PTSD symptoms resulting from psychological trauma contributed to the severity of drug use after
PTSD status was statistically controlled. To estimate the contribution of the specific type of event on drug use severity, the three types of traumatic events (Rape, Physical Assault, and Seeing someone hurt or killed) were entered simultaneously on the fifth step. Together, these variables did not produce a significant effect, F change (3, 71) = 1.29, p > 0.05. There was no significant interaction of PTSD diagnosis with type of traumatic event in the final step of the regression analysis for the three interaction terms taken together, F change (3,68) = 0.39, p > 0.05, R2 change = 0.01. The final model accounted for 25% of the variance in drug use severity. 5. Discussion Violent trauma and psychological distress in the lives of drug abusers are associated with the severity of drug addiction. The occurrence of PTSD symptoms was strongly associated with the severity of drug use. The relationship suggests that psychological distress associated exposure to trauma may be a risk factor for the progression of more severe drug use. Chronic drug use may dampen negative emotional responses associated with exposure to trauma, thereby increasing the probability of future drug use (Stasiewicz & Maisto, 1993). Our findings are consistent with other evidence showing that substance abuse increases in parallel with PTSD symptoms (Bremner, Southwick, Darnell, & Charney, 1996). Although drug use may serve to reduce negative affect associated with exposure to violent trauma, alleviating more severe drug abuse may unmask PTSD-related symptoms and increase subjective distress. More research is needed to understand the natural course of PTSD in drug abusers as well as the impact of treatment on these two disorders. Nonetheless, the interrelationship among these variables provides additional support for the simultaneous treatment of drug abuse and PTSD (Najavits, Weiss, & Leise, 1996; Ouimette, Brown, & Najavits, 1998). 5.1. Violent traumatic events, PTSD, and gender Women and men often differ with respect to the type of traumatic events they are prone to experience, and the lifestyles of drug-abusing patients may lead to a greater risk for exposure to gender-specific trauma. In the present study, rape was more frequently reported by women than by men. In contrast, there were no gender differences in the occurrence of physical assault or seeing someone hurt or killed, suggesting that in methadone patients, men and women are equally likely to be exposed to these violent traumatic events. A reciprocal relationship may exist whereby active drug use increases the risk of future violent traumatic events and previous exposure to violence increases the risk of subsequent drug use (Kilpatrick, Acierno, Resnick, Saunders, & Best, 1997). Given the high rates of exposure to
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violent traumatic events and the self-perpetuating cycle in this population, a clearer understanding of the relationship between violent traumatic events, PTSD, and drug use severity is desirable. This knowledge may allow the development of interventions to break this complicated cycle and improve drug abuse treatment outcomes. 5.2. PTSD and depressive symptoms The strong association between PTSD and depressive symptomatology among substance-abusing populations suggests it could be useful to assess PTSD and comorbid psychiatric disorders upon entry into treatment for substance abuse (Dansky, Roitzsch, Brady, & Saladin, 1997). The PTSD rate of 29% in this sample of methadone patients was substantially higher than that observed in general population studies, which have ranged from 1% to 9% (Breslau et al., 1991; Helzer et al., 1987; Kessler et al., 1995). This rate of PTSD was also substantially higher than the 14.2% rate in methadone maintenance patients previously reported by Villagomez et al. (1995). The latter difference may be related to the fact that over half of the patient pool declined to participate in the Villagomez and colleagues study; thus, more disordered individuals may have been inadvertently excluded. Moreover, methadone patients in our study with a history of PTSD were more likely than those without PTSD to be diagnosed with depression and dysthymia and to have higher levels of depressive symptoms and a higher rate of suicide attempts. Depressive symptoms also contributed to the severity of drug abuse. When these results are considered with respect to the additional variance accounted for in drug use severity by the experience of PTSD symptoms, it lends credence to the argument that subjective psychological distress plays a role in contributing to continued drug use. 5.3. Implications for substance abuse treatment settings The finding that 55% of patients who had a history of PTSD experienced PTSD symptoms within the previous six months is notable. These findings underscore the need for careful evaluation of treatment-seeking substance-abusing individuals who report a history of exposure to traumatic stressors (Ouimette et al., 1998). Assessment of primary symptoms for PTSD as well as PTSD-associated symptoms (e.g., guilt about acts committed or omitted during the traumatic episode, dysphoria, suicidality, homicidality, and social phobia) may assist the clinician in developing an appropriate treatment plan and in gaining a better understanding of the interplay between these symptoms and substance use (Ouimette et al., 1998; Triffleman, 1998). The association between the recency of PTSD symptoms and drug abuse severity is particularly important because untreated symptoms of PTSD may lead to relapse to substance use. Although untreated symptoms of PTSD
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may improve during periods of abstinence from substance use, some symptoms of PTSD (e.g., flashbacks, intrusive thoughts, and nightmares) appear to be more persistent and less likely to change in response to substance abuse treatment alone (Dansky, Brady, & Saladin, 1998). Additionally, in patients with comorbid substance use and PTSD, remission from PTSD is associated with better substance use outcomes, but remission from substance use is not associated with improved PTSD (Ouimette et al., 1998). Given these findings, it is reasonable to suggest that PTSD may not improve without treatment interventions specifically designed to target PTSD symptoms (Dansky et al., 1998). Furthermore, because men and women may differ in the types of traumatic events that they experience and in their psychological responses to trauma, PTSD treatments designed especially for women are needed (Gil-Rivas, Fiorentine, & Anglin, 1996; O'Donohue & Elliott, 1992). Women with comorbid substance use disorder and PTSD may benefit from cognitive-behavioral treatment in which substance abuse and PTSD are simultaneously addressed. In a recent study of a 24-session manual-guided cognitivebehavioral therapy for women, Najavits, Gastfriend, et al. (1998) found significant reductions in substance use and trauma-related symptoms from intake to 3-month follow-up. Although there are no published controlled trials of concurrent treatment for substance use and PTSD comorbidity, preliminary evidence suggests that concurrent treatment is effective in reducing substance use and PTSD symptoms (Ouimette et al., 1998). However, the effectiveness of this treatment approach requires further evaluation to ensure generalizability to other treatment settings and patient populations. Results from controlled trials of integrated or concurrent treatments in adult and adolescent samples will enhance our current knowledge about how to best treat patients presenting with this comorbidity. 5.4. Limitations Limitations of the study included the nature of the sample, all of whom were required to meet inclusion criteria for this clinical trial. They may not be fully representative of methadone patients. Because diagnostic evaluations were conducted prior to patients entering methadone treatment, acute stress may have influenced reporting of psychiatric symptoms. However, when compared with the findings of other drug-using populations seeking treatment, our prevalence estimates of PTSD are similar (Dansky et al., 1997; Wasserman et al., 1997). Another limitation is the fact that the C-DIS restricts respondents' reporting to a maximum of three traumatic events; therefore, our findings may underestimate the prevalence of violent traumatic events in this population. Future studies are needed to replicate these findings in other settings and to further clarify the relationship between PTSD status and treatment process and outcome variables.
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6. Conclusions The high rate of PTSD and exposure to violent traumatic events in this sample of methadone patients is notable, given that PTSD may be underdiagnosed in substance abuse treatment settings (Dansky et al., 1997). Untreated PTSD may increase drug use severity over time and may contribute to worse substance abuse treatment outcomes. These findings underscore the value of screening methadone patients for traumatic stress experiences and PTSD and providing PTSD-focused treatments given that such patients may benefit from interventions designed to target PTSD (Ouimette et al., 1998; Ouimette, Moos, & Finney, 2000). Acknowledgments This research was supported by National Institute on Drug Abuse Grant P50 DA09253. We express our thanks to Susan Alber, who assisted in the statistical programming for data analysis. References Beck, A. T., Steer, R. A., & Garbin, M. G. (1989). Psychometric properties of the Beck Depression Inventory: twenty-five years of evaluation. Clinical Psychology Review, 8, 77 ± 100. Beck, A. T., Ward, C. H., Mendelsohn, M., Mock, J., & Erbaugh, J. (1961). An inventory for measuring depression. Archives of General Psychiatry, 4, 561 ± 571. Brady, K. T., Killeen, T., Saladin, M. E., Dansky, B., & Becker, S. (1994). Comorbid substance abuse and posttraumatic stress disorder: characteristics of women in treatment. American Journal of Addictions, 3, 160 ± 164. Bremner, D. J., Southwick, S. M., Darnell, A., & Charney, D. S. (1996). Chronic PTSD in Vietnam combat veterans: course of illness and substance abuse. American Journal of Psychiatry, 153, 369 ± 375. Breslau, N., Davis, G. C., Andreski, P., & Peterson, E. (1991). Traumatic events and posttraumatic stress disorder in an urban population of young adults. Archives of General Psychiatry, 48, 216 ± 222. Brown, P. J., Stout, R. L., & Mueller, T. (1996). Posttraumatic stress disorder and substance abuse relapse among women: a pilot study. Psychology of Addictive Behaviors, 10, 124 ± 128. Cottler, L. B., Compton, W. M., Mager, D., Spitznagel, E. L., & Janca, A. (1992). Posttraumatic stress disorder among substance abusers from a general population. American Journal of Psychiatry, 149, 664 ± 670. Dansky, B. S., Brady, K. T., & Saladin, M. E. (1998). Untreated symptoms of PTSD among cocaine-dependent individuals. Journal of Substance Abuse Treatment, 15, 499 ± 504. Dansky, B. S., Brady, K. T., Saladin, M. E., Killeen, T., Becker, S., & Roitzsch, J. (1996). Victimization and PTSD in individuals with substance use disorders: gender and racial differences. The American Journal of Drug and Alcohol Abuse, 22, 75 ± 93. Dansky, B. S., Roitzsch, J. C., Brady, K. T., & Saladin, M. E. (1997). Posttraumatic stress disorder and substance abuse: use of research in a clinical setting. Journal of Traumatic Stress, 10, 141 ± 148. Fullilove, M. T., Fullilove, R. E., Smith, M., Winkler, K., Michael, C., Panzer, P. G., & Wallace, R. (1993). Violence, trauma, and posttraumatic stress disorder among women drug users. Journal of Traumatic Stress, 6, 533 ± 543.
Gil-Rivas, V., Fiorentine, R., & Anglin, M. D. (1996). Sexual abuse, physical abuse, and posttraumatic stress disorder among women participating in outpatient drug abuse treatment. Journal of Psychoactive Drugs, 28, 95 ± 102. Helzer, J. E., Robins, L. N., & McEvoy, L. (1987). Post-traumatic stress disorder in the general population: findings from the Epidemiological Catchment Area Study. New England Journal of Medicine, 317, 1630 ± 1634. Kessler, R. C., Sonnega, A., Bromet, E., Hughes, M., & Nelson, C. B. (1995). Posttraumatic stress disorder in the National Comorbidity Survey. Archives of General Psychiatry, 52, 1048 ± 1060. Kilpatrick, D. G., Acierno, R., Resnick, H. S., Saunders, B. E., & Best, C. L. (1997). A 2-year longitudinal analysis of the relationships between violent assault and substance use in women. Journal of Consulting and Clinical Psychology, 65, 834 ± 847. Kilpatrick, D. G., Saunders, B. E., Amick-McMullan, A., Best, C. L., Veronen, L. J., & Resnick, H. S. (1989). Victim and crime factors associated with the development of crime-related post-traumatic stress disorder. Behavior Therapy, 20, 199 ± 214. Levitan, R. D., Bouin, A. G., Navarro, J. R., & Hill, J. (1991). Validity of the computerized DIS for diagnosing psychiatric inpatients. Canadian Journal of Psychiatry, 36, 728 ± 731. McLellan, A. T., Alterman, A. I., Cacciola, J., Metzger, D., & O'Brien, C. P. (1992). A new measure of substance abuse treatment: initial studies of the treatment services review. The Journal of Nervous and Mental Disease, 180, 101 ± 110. Miller, M., Paone, D., & Friedman, P. (1995). Sexual violence and drug use severity among opiate users. (Unpublished manuscript). Najavits, L. M., Gastfriend, D. R., Barber, J. P., Reif, S., Muenz, L. R., Blaine, J., Frank, A., Crits-Christph, P., Thase, M., & Weiss, R. D. (1998). Cocaine dependence with and without PTSD among subjects in the National Institute on Drug Abuse Collaborative Cocaine Treatment Study. American Journal of Psychiatry, 155, 214 ± 219. Najavits, L. M., Weiss, R. D., & Liese, B. S. (1996). Group cognitivebehavioral therapy for women with PTSD and substance use disorder. Journal of Substance Abuse Treatment, 13, 13 ± 22. Najavits, L. M., Weiss, R. D., & Shaw, S. R. (1997). The link between substance abuse and posttraumatic stress disorder in women. The American Journal on Addictions, 6, 273 ± 283. Najavits, L. M., Weiss, R. D., Shaw, S. R., & Muenz, L. R. (1998). ``Seeking safety'': outcome of a new cognitive-behavioral psychotherapy for women with posttraumatic stress disorder and substance dependence. Journal of Traumatic Stress, 11, 437 ± 456. O'Donohue, W., & Elliott, A. (1992). The current status of post-traumatic stress disorder as a diagnostic category: problems and proposals. Journal of Traumatic Stress, 5, 421 ± 439. Ouimette, P. C., Brown, P. J., & Najavits, L. M. (1998). Course and treatment of patients with both substance use and posttraumatic stress disorders. Addictive Behaviors, 23, 785 ± 795. Ouimette, P. C., Moos, R. H., & Finney, J. W. (2000). Two-year mental health service use and course of remission in patients with substance use and posttraumatic stress disorders. Journal of Studies on Alcohol, 61, 247 ± 253. Paone, D., Miller, M., & Friedman, P. (1995). Sexual violence may predict HIV seropositivity (Unpublished manuscript). Resnick, H. S., Kilpatrick, D. G., Dansky, B. S., Saunders, B. E., & Best, C. L. (1993). Prevalence of civilian trauma and posttraumatic stress disorder in a representative national sample of women. Journal of Consulting and Clinical Psychology, 61, 984 ± 991. Robins, L. N., Helzer, J. E., Croughan, J. L., & Ratcliff, K. S. (1981). National Institute on Mental Health Diagnostic Interview Schedule: its history, characteristics and validity. Archives of General Psychiatry 38, 381 ± 389. Root, M. (1989). Treatment failures: the role of sexual victimization in women's addictive behavior. American Journal of Orthopsychiatry, 59, 542 ± 549. Sees, K. L., Delucchi, K. L., Masson, C. L., Rosen, A., Clark, H. W., Robillard, H., Banys, P., & Hall, S. M. (2000). Methadone main-
H.W. Clark et al. / Journal of Substance Abuse Treatment 20 (2001) 121±127 tenance vs. 180-day psychosocially enriched detoxification treatment of opioid dependence: a randomized controlled trial. Journal of the American Medical Association 283, 1303 ± 1310. Stasiewicz, P. R., & Maisto, S. A. (1993). Two-factor avoidance theory: the role of negative affect in the maintenance of substance use and substance use disorders. Behavior Therapy, 24, 337 ± 356. Triffleman, E. (1998). An overview of trauma exposure, posttraumatic stress disorder, and addictions. In: H. R. Kranzler, & B. J. Rounsaville (Eds.), Dual diagnosis and treatment ( pp. 263 ± 316). New York: Marcel Dekker.
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Villagomez, R. E., Meyer, T. J., Lin, M. M., & Brown, L. S. (1995). Posttraumatic stress disorder among inner city methadone patients. Journal of Substance Abuse Treatment, 12, 253 ± 257. Wasserman, D. A., Havassy, B. E., & Boles, S. M. (1997). Traumatic events and post-traumatic stress disorder in cocaine users entering private treatment. Drug and Alcohol Dependence, 46, 1 ± 8. Zanis, D. A., McLellan, A. T., Cnaan, R. A., & Randall, M. (1994). Reliability and validity of the Addiction Severity Index with a homeless sample. Journal of Substance Abuse Treatment, 6, 541 ± 548.
Regular article
Violent traumatic events and drug abuse severity H. Westley Clark, M.D., J.D.a,b,*, Carmen L. Masson, Ph.D.a, Kevin L. Delucchi, Ph.D.a, Sharon M. Hall, Ph.D.a, Karen L. Sees, D.O.a,b a
Department of Psychiatry, Langley Porter Psychiatric Institute, University of California-San Francisco, 401 Parnassus Avenue, San Francisco, CA 94143, USA b Department of Psychiatry, San Francisco Veterans Affairs Medical Center, 4150 Clement Street, San Francisco, CA 94121, USA Received 19 April 1999; received in revised form 17 July 2000; accepted 25 August 2000
Abstract We examined the occurrence of violent traumatic events, DSM-III-R diagnosis of posttraumatic stress disorder (PTSD), and PTSD symptoms, and the relationship of these variables to drug abuse severity. One-hundred fifty opioid-dependent drug abusers who were participants in a randomized trial of two methadone treatment interventions were interviewed using the Diagnostic Interview Schedule, the Addiction Severity Index, and the Beck Depression Inventory. Twenty-nine percent met diagnostic criteria for PTSD. With the exception of rape, no gender differences in the prevalence of violent traumatic events were observed. The occurrence of PTSD-related symptoms was associated with greater drug abuse severity after controlling for gender, depression, and lifetime diagnosis of PTSD. The high rate of PTSD among these methadone patients, the nature of the traumatic events to which they are exposed, and subsequent violence-related psychiatric sequelae have important implications for identification and treatment of PTSD among those seeking drug abuse treatment. D 2001 Elsevier Science Inc. All rights reserved. Keywords: Posttraumatic stress disorder; Depression; Drug abuse severity; Violence
1. Introduction Hard drug users (e.g., opioid users, cocaine users) are at high risk for experiencing violence, but the nature of the traumatic events that lead to the development of Posttraumatic Stress Disorder (PTSD) among drug users, and their association with drug use severity, is not completely understood. Among victims of crime, experiencing events that are perceived as life-threatening (e.g., rape and physical assault) is associated with the development of PTSD and other psychiatric disorders (Kilpatrick et al., 1989; Resnick, Kilpatrick, Dansky, Saunders, & Best, 1993). Also, individuals exposed to violent traumatic events may be at increased risk of substance abuse and depressive symptoms (Kilpatrick et al., 1989; Villagomez, Meyer, Lin, & Brown, 1995). These associations are relevant for the treatment of substance abuse because untreated PTSD and psychiatric * Corresponding author. SAMHSA/CSAT, Rockwall II, Suite 615, 5600 Fishers Lane, Rockville, MD 20857, USA. Tel.: +1-301-443-5700; fax: +1-301-443-8751. E-mail address: [email protected] (H.W. Clark).
comorbidities may lead to poor treatment outcomes (Brady, Killeen, Saladin, Dansky, & Becker, 1994; Brown, Stout, & Mueller, 1996; Root, 1989). A greater understanding of the extent to which violence-related PTSD and psychiatric comorbidities contribute to increased substance use and to relapse after drug abuse treatment may assist in the development of treatment strategies for this high-risk group. This study examined the relationship among violent traumatic events, PTSD, and the severity of drug abuse. There is a strong association between violent assault, PTSD, and drug abuse (Breslau, Davis, Andreski, & Peterson, 1991; Fullilove et al., 1993; Kessler, Sonnega, Bromet, Hughes, & Nelson, 1995). In a general population study, Cottler, Compton, Mager, Spitznagel, and Janca (1992) found that opioid and cocaine abusers were three times more likely to meet DSM-III diagnostic criteria for PTSD, compared to individuals without a substance use disorder. Substance abusers were also more likely to report physical assault as the precipitating traumatic event leading to PTSD (Cottler et al., 1992). In one of the few studies examining the association of violent traumatic events and PTSD among patients presenting for methadone treatment, Villagomez et
0740-5472/01/$ ± see front matter D 2001 Elsevier Science Inc. All rights reserved. PII: S 0 7 4 0 - 5 4 7 2 ( 0 0 ) 0 0 1 5 6 - 2
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al. (1995) reported that 14.2% of the sample met diagnostic criteria for PTSD. Estimates of PTSD in general population samples have ranged from approximately 1% to 9%, which is substantially lower than rates reported in studies of drug abusers (Breslau et al., 1991; Dansky et al., 1996; Helzer, Robins, & McEvoy, 1987; Kessler et al., 1995; Wasserman, Havassy, & Boles, 1997). Investigations of PTSD among drug abusers reveal a high prevalence rate of depressive symptoms and diagnoses (Najavits et al., 1998; Villagomez et al., 1995; Wasserman et al., 1997). Villagomez et al. (1995) reported that opioiddependent patients who met diagnostic criteria for PTSD at some point in their life were more likely than those without PTSD to experience depression and suicidal thoughts, and to make suicide attempts (see also Najavits, Weiss, Shaw, & Muenz, 1998; Wasserman et al., 1997). A history of violent trauma is also associated with more severe drug use, and riskier drug use and sexual behaviors (Miller et al., 1995; Paone, Miller, & Friedman, 1995). Understanding the extent to which violence-related PTSD and co-occurring depression may contribute to increased substance use is important, because these risk factors can be ameliorated by treatment (Najavits, 1997). The central objective of the present study was to assess the extent to which violent traumatic events, PTSD, and recency of PTSD-related symptoms contribute to drug use severity above and beyond the contribution of depressive symptomatology in methadone treatment patients. It is hypothesized that exposure to violent traumatic events will affect drug abuse severity over time in one of two ways: (a) recent experience of PTSD symptoms may lead to increased drug use or (b) untreated PTSD and psychiatric sequelae may take time to exert their effects on drug abuse severity in which drug use progressively increases over time. Knowledge about the recency of traumatic events exposure and PTSD symptoms may have important implications for the development of treatment interventions for those with cooccurring PTSD and drug abuse disorders. 2. Method 2.1. Participants Participants were the first 150 patients (59 women, 91 men) enrolled in a randomized, clinical trial comparing long-term (180-day) methadone detoxification plus an intensive psychosocial treatment versus methadone maintenance with a standard psychosocial treatment (Sees et al., 2000). Potential participants were evaluated for appropriateness for methadone treatment based upon physical examination, medical history, and indicated laboratory findings. Participants provided an observed urine sample that was tested for the presence of opioids. All participants were required to meet the following inclusion criteria: (1) DSM-III-R diagnosis of opioid dependence and (2) initial urine toxicology
screen positive for an opioid other than methadone and negative for methadone. In addition, the following exclusion criteria were applied: (1) any acute medical illness which contraindicated initiating methadone treatment (e.g., acute hepatitis); (2) inaccessible veins for venipuncture; (3) current enrollment in substance abuse treatment elsewhere; (4) enrollment in a methadone treatment program within the previous seven days or in the follow-up phase from a previous methadone detoxification research protocol; (5) not expected to remain available in the study for 12 months; and (6) no evidence of opioid withdrawal to start on methadone (i.e., three attempts). If participants met criteria for inclusion in the study, they read and signed a copy of the university-review-board-approved consent form. The University of California, San Francisco, Committee on Human Research approved the study. Patients were predominantly Caucasian (52.6%), male (61%), never married (38%), and unemployed (50%). The mean age was 43.7 years (SD = 2.38). Most had histories of arrests or convictions (67.3%), but no current legal restraints, were not homeless (97.3%), and had a high school education or less (mean years of education = 11.9). A majority reported prior drug abuse treatment (139 out of 150; 93%). Approximately 85% met DSM-III-R criteria for severe heroin dependence, 14% for moderate dependence, and less than 1% for mild dependence. 3. Measures The measures examined in the current study were part of a larger battery of questionnaires administered in the clinical trial. Participants were interviewed at baseline and monthly for 12 months. Information on demographic characteristics, substance use, and psychiatric diagnoses and symptoms was obtained at treatment entry and all subsequent analyses are based on this baseline data. The Computerized Diagnostic Interview Schedule (CDIS) was used to assess substance use and psychiatric disorders as defined by DSM-III-R (Robbins et al., 1981; Levitan et al., 1991). The sections on substance use disorders, Posttraumatic Stress Disorder, Depression, and Dysthymia are included in this report. For each disorder, participants were given a diagnosis of PTSD if they met full diagnostic criteria at some point in their life. The recency of PTSD-related symptoms associated with each traumatic event was rated on a six-point scale: (1) within the last two weeks; (2) two weeks to less than a month ago; (3) one month to less than six months ago; (4) six months to less than a year ago; (5) sometime in the last twelve months; and (6) more than one year ago. The Beck Depression Inventory (BDI) (Beck, Ward, Mendelsohn, Mock, & Erbaugh, 1961) is a 21-item questionnaire designed to assess level of depressive symptoms. This instrument has been successfully used to screen depression in a variety of psychiatric and normal
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populations, including substance abusers (Beck, Steer, & Garbin, 1989). The Addiction Severity Index (ASI) (McLellan, Alterman, Cacciola, Metzger, & O'Brien, 1992) is a structured clinical interview that assesses current and lifetime drug and alcohol use. It provides severity ratings and composite scores in seven functional areas (medical, alcohol, drug, legal, social, employment, and psychological) commonly impaired among substance abusers. This instrument has been demonstrated to have acceptable levels of reliability and validity with several substance-abusing populations (McLellan et al., 1992; Zanis, McLellan, Cnaan, & Randall, 1994). 3.1. Procedure Participants who met eligibility criteria, gave informed consent, and completed the intake procedures were randomized to either long-term (180-day) methadone detoxification or methadone maintenance at the time that they presented in opioid withdrawal. The demographics questionnaire and standardized measures were administered before the participant was assigned to either treatment condition and received the first methadone dose. C-DIS questions were read aloud to participants. The C-DIS computer-scoring program was used to generate diagnoses and current PTSD-related symptoms. For each psychiatric disorder identified by the C-DIS, participants were given a diagnosis if they met full diagnostic criteria at any time in their life. Current PTSD-related symptoms were defined as having at least one symptom of the disorder in the past 6 months, once having met the full diagnostic criteria for PTSD, on the basis of DSM-III-R criteria. 3.2. Statistical analyses Analyses were conducted to estimate the rates of PTSD, violent traumatic events, and depression in this sample of methadone patients and to examine gender differences in the occurrence of violent traumatic events. Descriptive statistics were used to summarize sociodemographic and substance use characteristics of the sample. Groups were compared using independent t-tests or ANOVA for the continuous measures and chi-square tests for the categorical. In addition, separate logistic regression models were used to test the effects of PTSD status and gender on each of the three Table 1 Distribution of violent traumatic events by gender Women (n = 59)
Men (n = 91)
Events
No. of events
%
No. of events
%
Rape Seeing someone hurt/killed Physical assault Total
24 20 8 52
46.1 38.5 15.4 100.0
2 34 27 63
3.2 54.0 42.8 100.0
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types of violent traumatic events experienced (i.e., rape, physical assault, and seeing someone hurt or killed; see Table 1). Finally, a hierarchical multiple regression analysis was conducted to determine the relationship of history of PTSD, recency of PTSD symptoms, and the type of violent traumatic event to drug use severity. 4. Results 4.1. Demographic and drug use characteristics There were no significant differences between the groups with and without PTSD for any sociodemographic characteristics with the exception of marital status. Participants who did not meet DSM-III-R criteria for PTSD were more likely to never have been married, c2 (4) = 11.94, p = 0.016. In addition, there were no significant differences between men and women in the diagnosis of mild/moderate (14% vs. 15%) versus severe (86% vs. 85%) heroin dependence, P2 (1) = 0.03, n.s. 4.2. Diagnosis of posttraumatic stress disorder Of the 150 patients, 44 (29%) were classified as having had a DSM-III-R diagnosis of PTSD at some point in their life. A significantly higher percentage of women (53%; 31 out of 59) than men (14%; 13 out of 91) met diagnostic criteria for PTSD, c2 (1) = 25.27, p < 0.001. Fifty-five percent of the participants who had a history of PTSD also reported PTSD-related symptoms in the past 6 months. 4.3. Exposure to traumatic events A total of 219 traumatic events as defined by the DSMIII-R were reported by 108 of the patients (M = 2.0 events per participant). Seventy-two percent of the sample reported exposure to at least one traumatic event. Those meeting diagnostic criteria for PTSD reported a greater total number of traumatic events (M = 2.2, SD = 0.88 vs. M = 1.15, SD = 1.14, t (103) = 6.11, p < 0.001, than those who did not meet diagnostic criteria for the disorder. The C-DIS limits respondents' reporting to a maximum of three traumatic events. Therefore, for each of the three main traumatic events of interest (rape, physical assault, and seeing someone hurt or killed), the total number of reported occurrences was limited to three. Because only a small percentage of the sample experienced more than one of each of these (28 out of 150; 19%), we dichotomized the violent traumatic events of rape, physical assault, and seeing someone hurt or killed to examine differences between those who had or had not experienced such an event. Three separate logistic regression models were used to test the relationship between each of the three violent traumatic events and PTSD status, gender, and their interaction. The model predicting occurrence of rape versus not was not
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statistically significant ( ÿ 2Log Likelihood c2 (3) = 33.6, p = 0.001). Of the individual Wald c2 tests for each parameter, only the one for gender was significant ( p = 0.0031), with women more likely to experience rape than men. No independent associations were identified for physical assault or seeing someone hurt or killed. 4.4. PTSD status, depression, dysthymia, and suicide attempts Those with a history of PTSD also reported a history of depression, dysthymia, and suicide attempts. Participants with a history of PTSD were also more likely to be diagnosed with depression: 46% (20 out of 44) as compared with 14% (15 out of 106) of those who had not had PTSD, c2 (1) = 17.03, p < 0.001. Similarly, those diagnosed with PTSD (9 out of 44, 21%) were more likely to be diagnosed with dysthymia than those without a history of PTSD (7 of 106, 7%; c2 (1) = 6.26, p < 0.05). PTSD was also associated with suicide attempts among those who had experienced PTSD at some point in their life (64%, 16 out of 25) than among those without such a history: 36% (9 of 25), P2 (1) = 17.15, p < 0.001. These results suggest that methadone maintenance patients with PTSD are more likely to have comorbid disorders than those without. Corroborating evidence of psychiatric comorbidity between PTSD and depressive disorders was estimated with the BDI. A 2 2 ANOVA of BDI scores revealed a significant main effect for PTSD status, with higher BDI scores among participants with PTSD as compared to those without PTSD, F (1,140) = 3.76, p < 0.05. There was no main effect of gender [F (1,140) = 2.11, n.s.], nor did PTSD status interact with gender [F (1,140) = 1.39, n.s.]. 4.5. PTSD diagnosis and symptoms, types of traumatic events, and ASI drug use severity A hierarchical multiple regression analysis was estimated and tested to examine the effects of history of PTSD diagnosis, recency of PTSD symptoms, and the type of traumatic event on the severity of drug use (as measured by the ASI). Gender and BDI scores, which are known to be related to drug use severity, were first entered into the model. Because psychological distress is a risk factor for substance use and may produce vulnerability to greater drug use severity, diagnosis of PTSD was entered in step 3 before recency of PTSD-related symptoms and the types of traumatic events leading to PTSD. PTSD status did not have a significant effect on drug use severity, F < 1, once gender and depression were already in the model. Recency of PTSD symptoms was entered in the fourth step and produced a significant increase in the prediction of drug use severity scores, R2 change = 0.09, F (1,74) = 7.94, p < 0.01. These findings suggest that past experience of PTSD symptoms resulting from psychological trauma contributed to the severity of drug use after
PTSD status was statistically controlled. To estimate the contribution of the specific type of event on drug use severity, the three types of traumatic events (Rape, Physical Assault, and Seeing someone hurt or killed) were entered simultaneously on the fifth step. Together, these variables did not produce a significant effect, F change (3, 71) = 1.29, p > 0.05. There was no significant interaction of PTSD diagnosis with type of traumatic event in the final step of the regression analysis for the three interaction terms taken together, F change (3,68) = 0.39, p > 0.05, R2 change = 0.01. The final model accounted for 25% of the variance in drug use severity. 5. Discussion Violent trauma and psychological distress in the lives of drug abusers are associated with the severity of drug addiction. The occurrence of PTSD symptoms was strongly associated with the severity of drug use. The relationship suggests that psychological distress associated exposure to trauma may be a risk factor for the progression of more severe drug use. Chronic drug use may dampen negative emotional responses associated with exposure to trauma, thereby increasing the probability of future drug use (Stasiewicz & Maisto, 1993). Our findings are consistent with other evidence showing that substance abuse increases in parallel with PTSD symptoms (Bremner, Southwick, Darnell, & Charney, 1996). Although drug use may serve to reduce negative affect associated with exposure to violent trauma, alleviating more severe drug abuse may unmask PTSD-related symptoms and increase subjective distress. More research is needed to understand the natural course of PTSD in drug abusers as well as the impact of treatment on these two disorders. Nonetheless, the interrelationship among these variables provides additional support for the simultaneous treatment of drug abuse and PTSD (Najavits, Weiss, & Leise, 1996; Ouimette, Brown, & Najavits, 1998). 5.1. Violent traumatic events, PTSD, and gender Women and men often differ with respect to the type of traumatic events they are prone to experience, and the lifestyles of drug-abusing patients may lead to a greater risk for exposure to gender-specific trauma. In the present study, rape was more frequently reported by women than by men. In contrast, there were no gender differences in the occurrence of physical assault or seeing someone hurt or killed, suggesting that in methadone patients, men and women are equally likely to be exposed to these violent traumatic events. A reciprocal relationship may exist whereby active drug use increases the risk of future violent traumatic events and previous exposure to violence increases the risk of subsequent drug use (Kilpatrick, Acierno, Resnick, Saunders, & Best, 1997). Given the high rates of exposure to
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violent traumatic events and the self-perpetuating cycle in this population, a clearer understanding of the relationship between violent traumatic events, PTSD, and drug use severity is desirable. This knowledge may allow the development of interventions to break this complicated cycle and improve drug abuse treatment outcomes. 5.2. PTSD and depressive symptoms The strong association between PTSD and depressive symptomatology among substance-abusing populations suggests it could be useful to assess PTSD and comorbid psychiatric disorders upon entry into treatment for substance abuse (Dansky, Roitzsch, Brady, & Saladin, 1997). The PTSD rate of 29% in this sample of methadone patients was substantially higher than that observed in general population studies, which have ranged from 1% to 9% (Breslau et al., 1991; Helzer et al., 1987; Kessler et al., 1995). This rate of PTSD was also substantially higher than the 14.2% rate in methadone maintenance patients previously reported by Villagomez et al. (1995). The latter difference may be related to the fact that over half of the patient pool declined to participate in the Villagomez and colleagues study; thus, more disordered individuals may have been inadvertently excluded. Moreover, methadone patients in our study with a history of PTSD were more likely than those without PTSD to be diagnosed with depression and dysthymia and to have higher levels of depressive symptoms and a higher rate of suicide attempts. Depressive symptoms also contributed to the severity of drug abuse. When these results are considered with respect to the additional variance accounted for in drug use severity by the experience of PTSD symptoms, it lends credence to the argument that subjective psychological distress plays a role in contributing to continued drug use. 5.3. Implications for substance abuse treatment settings The finding that 55% of patients who had a history of PTSD experienced PTSD symptoms within the previous six months is notable. These findings underscore the need for careful evaluation of treatment-seeking substance-abusing individuals who report a history of exposure to traumatic stressors (Ouimette et al., 1998). Assessment of primary symptoms for PTSD as well as PTSD-associated symptoms (e.g., guilt about acts committed or omitted during the traumatic episode, dysphoria, suicidality, homicidality, and social phobia) may assist the clinician in developing an appropriate treatment plan and in gaining a better understanding of the interplay between these symptoms and substance use (Ouimette et al., 1998; Triffleman, 1998). The association between the recency of PTSD symptoms and drug abuse severity is particularly important because untreated symptoms of PTSD may lead to relapse to substance use. Although untreated symptoms of PTSD
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may improve during periods of abstinence from substance use, some symptoms of PTSD (e.g., flashbacks, intrusive thoughts, and nightmares) appear to be more persistent and less likely to change in response to substance abuse treatment alone (Dansky, Brady, & Saladin, 1998). Additionally, in patients with comorbid substance use and PTSD, remission from PTSD is associated with better substance use outcomes, but remission from substance use is not associated with improved PTSD (Ouimette et al., 1998). Given these findings, it is reasonable to suggest that PTSD may not improve without treatment interventions specifically designed to target PTSD symptoms (Dansky et al., 1998). Furthermore, because men and women may differ in the types of traumatic events that they experience and in their psychological responses to trauma, PTSD treatments designed especially for women are needed (Gil-Rivas, Fiorentine, & Anglin, 1996; O'Donohue & Elliott, 1992). Women with comorbid substance use disorder and PTSD may benefit from cognitive-behavioral treatment in which substance abuse and PTSD are simultaneously addressed. In a recent study of a 24-session manual-guided cognitivebehavioral therapy for women, Najavits, Gastfriend, et al. (1998) found significant reductions in substance use and trauma-related symptoms from intake to 3-month follow-up. Although there are no published controlled trials of concurrent treatment for substance use and PTSD comorbidity, preliminary evidence suggests that concurrent treatment is effective in reducing substance use and PTSD symptoms (Ouimette et al., 1998). However, the effectiveness of this treatment approach requires further evaluation to ensure generalizability to other treatment settings and patient populations. Results from controlled trials of integrated or concurrent treatments in adult and adolescent samples will enhance our current knowledge about how to best treat patients presenting with this comorbidity. 5.4. Limitations Limitations of the study included the nature of the sample, all of whom were required to meet inclusion criteria for this clinical trial. They may not be fully representative of methadone patients. Because diagnostic evaluations were conducted prior to patients entering methadone treatment, acute stress may have influenced reporting of psychiatric symptoms. However, when compared with the findings of other drug-using populations seeking treatment, our prevalence estimates of PTSD are similar (Dansky et al., 1997; Wasserman et al., 1997). Another limitation is the fact that the C-DIS restricts respondents' reporting to a maximum of three traumatic events; therefore, our findings may underestimate the prevalence of violent traumatic events in this population. Future studies are needed to replicate these findings in other settings and to further clarify the relationship between PTSD status and treatment process and outcome variables.
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6. Conclusions The high rate of PTSD and exposure to violent traumatic events in this sample of methadone patients is notable, given that PTSD may be underdiagnosed in substance abuse treatment settings (Dansky et al., 1997). Untreated PTSD may increase drug use severity over time and may contribute to worse substance abuse treatment outcomes. These findings underscore the value of screening methadone patients for traumatic stress experiences and PTSD and providing PTSD-focused treatments given that such patients may benefit from interventions designed to target PTSD (Ouimette et al., 1998; Ouimette, Moos, & Finney, 2000). Acknowledgments This research was supported by National Institute on Drug Abuse Grant P50 DA09253. We express our thanks to Susan Alber, who assisted in the statistical programming for data analysis. References Beck, A. T., Steer, R. A., & Garbin, M. G. (1989). Psychometric properties of the Beck Depression Inventory: twenty-five years of evaluation. Clinical Psychology Review, 8, 77 ± 100. Beck, A. T., Ward, C. H., Mendelsohn, M., Mock, J., & Erbaugh, J. (1961). An inventory for measuring depression. Archives of General Psychiatry, 4, 561 ± 571. Brady, K. T., Killeen, T., Saladin, M. E., Dansky, B., & Becker, S. (1994). Comorbid substance abuse and posttraumatic stress disorder: characteristics of women in treatment. American Journal of Addictions, 3, 160 ± 164. Bremner, D. J., Southwick, S. M., Darnell, A., & Charney, D. S. (1996). Chronic PTSD in Vietnam combat veterans: course of illness and substance abuse. American Journal of Psychiatry, 153, 369 ± 375. Breslau, N., Davis, G. C., Andreski, P., & Peterson, E. (1991). Traumatic events and posttraumatic stress disorder in an urban population of young adults. Archives of General Psychiatry, 48, 216 ± 222. Brown, P. J., Stout, R. L., & Mueller, T. (1996). Posttraumatic stress disorder and substance abuse relapse among women: a pilot study. Psychology of Addictive Behaviors, 10, 124 ± 128. Cottler, L. B., Compton, W. M., Mager, D., Spitznagel, E. L., & Janca, A. (1992). Posttraumatic stress disorder among substance abusers from a general population. American Journal of Psychiatry, 149, 664 ± 670. Dansky, B. S., Brady, K. T., & Saladin, M. E. (1998). Untreated symptoms of PTSD among cocaine-dependent individuals. Journal of Substance Abuse Treatment, 15, 499 ± 504. Dansky, B. S., Brady, K. T., Saladin, M. E., Killeen, T., Becker, S., & Roitzsch, J. (1996). Victimization and PTSD in individuals with substance use disorders: gender and racial differences. The American Journal of Drug and Alcohol Abuse, 22, 75 ± 93. Dansky, B. S., Roitzsch, J. C., Brady, K. T., & Saladin, M. E. (1997). Posttraumatic stress disorder and substance abuse: use of research in a clinical setting. Journal of Traumatic Stress, 10, 141 ± 148. Fullilove, M. T., Fullilove, R. E., Smith, M., Winkler, K., Michael, C., Panzer, P. G., & Wallace, R. (1993). Violence, trauma, and posttraumatic stress disorder among women drug users. Journal of Traumatic Stress, 6, 533 ± 543.
Gil-Rivas, V., Fiorentine, R., & Anglin, M. D. (1996). Sexual abuse, physical abuse, and posttraumatic stress disorder among women participating in outpatient drug abuse treatment. Journal of Psychoactive Drugs, 28, 95 ± 102. Helzer, J. E., Robins, L. N., & McEvoy, L. (1987). Post-traumatic stress disorder in the general population: findings from the Epidemiological Catchment Area Study. New England Journal of Medicine, 317, 1630 ± 1634. Kessler, R. C., Sonnega, A., Bromet, E., Hughes, M., & Nelson, C. B. (1995). Posttraumatic stress disorder in the National Comorbidity Survey. Archives of General Psychiatry, 52, 1048 ± 1060. Kilpatrick, D. G., Acierno, R., Resnick, H. S., Saunders, B. E., & Best, C. L. (1997). A 2-year longitudinal analysis of the relationships between violent assault and substance use in women. Journal of Consulting and Clinical Psychology, 65, 834 ± 847. Kilpatrick, D. G., Saunders, B. E., Amick-McMullan, A., Best, C. L., Veronen, L. J., & Resnick, H. S. (1989). Victim and crime factors associated with the development of crime-related post-traumatic stress disorder. Behavior Therapy, 20, 199 ± 214. Levitan, R. D., Bouin, A. G., Navarro, J. R., & Hill, J. (1991). Validity of the computerized DIS for diagnosing psychiatric inpatients. Canadian Journal of Psychiatry, 36, 728 ± 731. McLellan, A. T., Alterman, A. I., Cacciola, J., Metzger, D., & O'Brien, C. P. (1992). A new measure of substance abuse treatment: initial studies of the treatment services review. The Journal of Nervous and Mental Disease, 180, 101 ± 110. Miller, M., Paone, D., & Friedman, P. (1995). Sexual violence and drug use severity among opiate users. (Unpublished manuscript). Najavits, L. M., Gastfriend, D. R., Barber, J. P., Reif, S., Muenz, L. R., Blaine, J., Frank, A., Crits-Christph, P., Thase, M., & Weiss, R. D. (1998). Cocaine dependence with and without PTSD among subjects in the National Institute on Drug Abuse Collaborative Cocaine Treatment Study. American Journal of Psychiatry, 155, 214 ± 219. Najavits, L. M., Weiss, R. D., & Liese, B. S. (1996). Group cognitivebehavioral therapy for women with PTSD and substance use disorder. Journal of Substance Abuse Treatment, 13, 13 ± 22. Najavits, L. M., Weiss, R. D., & Shaw, S. R. (1997). The link between substance abuse and posttraumatic stress disorder in women. The American Journal on Addictions, 6, 273 ± 283. Najavits, L. M., Weiss, R. D., Shaw, S. R., & Muenz, L. R. (1998). ``Seeking safety'': outcome of a new cognitive-behavioral psychotherapy for women with posttraumatic stress disorder and substance dependence. Journal of Traumatic Stress, 11, 437 ± 456. O'Donohue, W., & Elliott, A. (1992). The current status of post-traumatic stress disorder as a diagnostic category: problems and proposals. Journal of Traumatic Stress, 5, 421 ± 439. Ouimette, P. C., Brown, P. J., & Najavits, L. M. (1998). Course and treatment of patients with both substance use and posttraumatic stress disorders. Addictive Behaviors, 23, 785 ± 795. Ouimette, P. C., Moos, R. H., & Finney, J. W. (2000). Two-year mental health service use and course of remission in patients with substance use and posttraumatic stress disorders. Journal of Studies on Alcohol, 61, 247 ± 253. Paone, D., Miller, M., & Friedman, P. (1995). Sexual violence may predict HIV seropositivity (Unpublished manuscript). Resnick, H. S., Kilpatrick, D. G., Dansky, B. S., Saunders, B. E., & Best, C. L. (1993). Prevalence of civilian trauma and posttraumatic stress disorder in a representative national sample of women. Journal of Consulting and Clinical Psychology, 61, 984 ± 991. Robins, L. N., Helzer, J. E., Croughan, J. L., & Ratcliff, K. S. (1981). National Institute on Mental Health Diagnostic Interview Schedule: its history, characteristics and validity. Archives of General Psychiatry 38, 381 ± 389. Root, M. (1989). Treatment failures: the role of sexual victimization in women's addictive behavior. American Journal of Orthopsychiatry, 59, 542 ± 549. Sees, K. L., Delucchi, K. L., Masson, C. L., Rosen, A., Clark, H. W., Robillard, H., Banys, P., & Hall, S. M. (2000). Methadone main-
H.W. Clark et al. / Journal of Substance Abuse Treatment 20 (2001) 121±127 tenance vs. 180-day psychosocially enriched detoxification treatment of opioid dependence: a randomized controlled trial. Journal of the American Medical Association 283, 1303 ± 1310. Stasiewicz, P. R., & Maisto, S. A. (1993). Two-factor avoidance theory: the role of negative affect in the maintenance of substance use and substance use disorders. Behavior Therapy, 24, 337 ± 356. Triffleman, E. (1998). An overview of trauma exposure, posttraumatic stress disorder, and addictions. In: H. R. Kranzler, & B. J. Rounsaville (Eds.), Dual diagnosis and treatment ( pp. 263 ± 316). New York: Marcel Dekker.
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Villagomez, R. E., Meyer, T. J., Lin, M. M., & Brown, L. S. (1995). Posttraumatic stress disorder among inner city methadone patients. Journal of Substance Abuse Treatment, 12, 253 ± 257. Wasserman, D. A., Havassy, B. E., & Boles, S. M. (1997). Traumatic events and post-traumatic stress disorder in cocaine users entering private treatment. Drug and Alcohol Dependence, 46, 1 ± 8. Zanis, D. A., McLellan, A. T., Cnaan, R. A., & Randall, M. (1994). Reliability and validity of the Addiction Severity Index with a homeless sample. Journal of Substance Abuse Treatment, 6, 541 ± 548.