Contingency management is especially efficacious in engendering long durations of abstinence in patients with sexual abuse histories.

Contingency management (CM) treatments provide positive reinforcers upon evidence of objective behavioral change. Typically, they involve reinforcing abstinence or other positive treatment behaviors with vouchers exchangeable for retail goods or services or the chance to win prizes of varying magnitudes. CM can be provided as an adjunct to usual care procedures in any type of substance abuse treatment program, and its efficacy has been firmly established in randomized trials (Peirce et al., 2006; Petry & Martin, 2002; Petry, Alessi, Marx, Austin, & Tardif, 2005a; Petry, Martin, Cooney, & Kranzler, 2000; Petry, Martin, & Simcic, 2005b; Petry et al., 2004; 2005c; 2006a; Stanger, Budney, Kamon, & Thostensen, 2009) as well as meta-analyses (Dutra et al., 2008; Lussier, Heil, Mongeon, Badger, & Higgins, 2006; Prendergast, Podus, Finney, Greenwell, & Roll, 2006). Individuals seeking substance abuse treatment who have histories of sexual abuse often present with severe psychiatric symptoms (e.g., dissociation, affect dysregulation, somatization, unstable and conflictual relationships) (Schafer, Schnack, & Soyka, 2000) that are negative prognostic factors for substance abuse treatment (Cohen & Hien, 2006; Hien, Cohen, & Campbell, 2005; Shane, Diamond, Mensinger, Shera, & Wintersteen, 2006). Estimates of the prevalence of sexual abuse in substance abuse treatment samples range from 11% to 84% (Evran et al., 2006; Freeman et al., 2002; Medrano et al., 1999). CM interventions may be particularly well suited to helping patients with histories of sexual abuse, because they have been shown to be efficacious in treating dual-diagnosis patients, particularly those with more severe psychopathology. Studies reporting benefits of CM with dual-diagnosis patients have been conducted with military veterans (Drebing et al., 2005; 2007), homeless individuals (McNamara, Schumacher, Milby, Wallace, & Usdan, 2001; Milby et al., 2000; Tracy et al., 2007), and patients with schizophrenia (Roll, Higgins, Steingard, & McGinley, 1998; Shaner et al., 1997; Tidey, Higgins, Bickel, & Steingard, 1999; Tidey, O’Neill, & Higgins, 2002). Further, some reports note that behavioral treatments such as CM are especially effective in dual-diagnosis patients. For example, in a sample of cocaine-abusing buprenorphine maintained patients, Gonzalez, Feingold, Oliveto, Gonsai, and Kosten (2003) found that CM increased drug-negative urine submission rates to a greater extent among patients with a history of major depressive disorder than among those with no history of major depression. Two studies provide indirect evidence that CM may be particularly efficacious with patients who have histories of abuse and related psychiatric symptoms. Lester and colleagues (2007) found that among 118 homeless cocaine-dependent adults, those with trauma exposure and posttraumatic stress disorder (PTSD) symptoms had significantly greater reductions in trauma-related symptoms when assigned to CM treatments than when assigned to less intensive treatment. Although PTSD is a common sequela of sexual abuse, that study did not investigate the role of abuse history specifically as a predictor of substance abuse treatment outcome. In another study, Ford, Hawke, Alessi, Ledgerwood, and Petry (2007a) examined treatment outcomes of 142 substance abusers randomized to standard care or standard care plus CM. History of sexual abuse was not associated with treatment outcome per se, but patients with high levels of PTSD symptoms were more likely to be abstinent at a 9-month follow-up than those with less severe PTSD symptoms in the CM condition only. Thus, patients with trauma-induced symptoms were particularly responsive to CM in terms of long-term abstinence outcomes. The null finding regarding sexual abuse as a general prognostic factor may be due to the limited statistical power in the relatively small sample included in that study, in which only 48 participants reported histories of sexual abuse. The present study examined the association of a history of sexual abuse with treatment outcomes within a larger sample of cocaine abusing patients recruited in three studies (Petry et al., 2004; 2005a; 2006a) conducted in community-based clinics in which standard care was provided with and without CM. We anticipated that sexual abuse histories would be associated with more severe psychiatric and social problems. Because of CM’s focus on concrete, frequent positive reinforcement and its efficacy in reducing PTSD symptoms (Lester et al., 2007), we hypothesized that patients with histories of sexual abuse would show greater improvements with CM treatments than patients with no history of sexual abuse.