مواجهه طولانی مدت با بیماران مبتلا به PTSD مزمن: پیش بینی نتیجه درمان و ترک تحصیل

The present study investigated predictors of treatment outcome and dropout in two samples of PTSD-patients with mixed traumas treated using prolonged imaginal exposure. Possible predictors were analysed in both samples separately, in order to replicate in one sample findings found in the other. The only stable finding across the two groups was that patients who showed more PTSD-symptoms at pre-treatment, showed more PTSD-symptoms at post-treatment and follow-up. Indications were found that benzodiazepine use was related to both treatment outcome and dropout, and alcohol use to dropout. Demographic variables, depression and general anxiety, personality, trauma characteristics, feelings of anger, guilt, and shame and nonspecific variables regarding therapy were not related to either treatment outcome or dropout, disconfirming generally held beliefs about these factors as contra-indications for exposure therapy. It is concluded that it is difficult to use pre-treatment variables as a powerful and reliable tool for predicting treatment outcome or dropout. Clinically seen, it is therefore argued that exclusion of PTSD-patients from prolonged exposure treatment on the basis of pre-treatment characteristics is not justified.

In several controlled studies, prolonged exposure techniques have been demonstrated to be effective in the treatment of post-traumatic stress disorder (PTSD; Boudewyns & Hyer, 1990, Cooper & Clum, 1989, Foa et al., 1999 and Keane, Fairbank, Caddell, & Zimering, 1989; Marks, Lovell, Noshirvani, Livanou, & Thrasher, 1998; Tarrier et al., 1999). Foa and Meadows (1997) concluded that “given the state of art (…), prolonged exposure might be considered the treatment of choice for PTSD”. Nevertheless, studies show that a considerable number of PTSD patients, about 25 to 45%, still fulfil diagnostic criteria for PTSD at the end of treatment, indicating that exposure therapy may lead to improvement, but not to recovery in all cases. Enhancing knowledge of the prognostic features which affect treatment outcome is important for several reasons. First, this knowledge can be helpful in indicating treatments of choice, especially since other effective treatments, such as cognitive restructuring therapy, are available (Foa et al., 1999, Marks et al., 1998 and Tarrier et al., 1999). Second, increased knowledge about the factors associated with exposure treatment failure may lead to insight into the fundamental processes underlying exposure, and eventually to adaptations in the exposure treatment procedures, in order to improve the patients' prognosis. Third, an early identification of possible treatment dropouts enables the therapist to adjust treatment delivery and planning, in order to prevent dropout. Before presenting our study, an overview is offered of research findings regarding prognostic factors of development or maintenance of PTSD-symptoms. With regard to (1) demographic variables, several studies revealed that younger people were more prone to develop PTSD than older people ( Norris, 1992 and Van der Kolk, 1987; Wolfe, Erickson, Sharkansky, King, & King, 1999). It is assumed that younger people have more trouble recovering from a trauma, due to their underdevelopment in neurological paths ( McFarlane, 1989 and Van der Kolk, 1987). In treatment outcome studies, age and outcome tended to be unrelated ( Ehlers et al., 1998; Foa, Rothbaum, Riggs, & Murdock, 1991; Jaycox, Foa, & Morral, 1998; Marks et al., 1998; Munley, Bains, Frazee, & Schwartz, 1994; Tarrier, Sommerfield, Pilgrim, & Faragher, 2000). Several studies indicated that the risk of developing PTSD following exposure to a traumatic event was greater in women than in men ( Breslau, Davis, Andreski, & Peterson, 1991, Norris, 1992 and Wolfe et al., 1999). This finding may have resulted partly from the fact that women are more prone to sexual assault, traumas known to have a high risk for subsequent pathology development. Tarrier et al. (2000) found females to have better treatment outcomes. In other treatment outcome studies, however, no sex differences were found ( Jaycox et al., 1998 and Marks et al., 1998). Other demographic variables such as marital status, employment, level of education ( Ehlers et al., 1998, Foa et al., 1991 and Tarrier et al., 2000), and IQ ( Munley et al., 1994) were found to be unrelated to treatment outcome. In one study, people who did not work were more liable to drop out of treatment than those who did ( Foa et al., 1999), but in other studies no differences were found in demographic variables between dropouts and completers ( Marks et al., 1998 and Tarrier et al., 1999). Several studies found (2) substance abuse (alcohol, marihuana, benzodiazepines or heroine) to be associated with the development of PTSD ( Fischer, 1991, Reifmann & Windle, 1996 and Ruzek, Polusny, & Abueg, 1998). Pitman et al. (1991) found that alcohol abuse may cause severe complications during exposure therapy. It is assumed that alcohol or drugs abuse interferes with treatment outcome or is predictive of noncompliance and eventually of dropout ( Perconte & Griger, 1991). Nevertheless, Tarrier et al. (2000) found no relationship between the use of psychotropic medication and treatment outcome. With regard to (3) severity of symptoms, conflicting results are reported. One study ( Perconte & Griger, 1991) found a relationship between a greater number of PTSD symptoms at pre-treatment and poor treatment outcome, whilst another ( Foa, Riggs, Massie, & Yarczower, 1995) found that this related to a better outcome. In the latter study, patients with severe symptoms showed more fear activation during exposure sessions, and thus better outcome. Marks et al. (1998) found that dropouts had slightly more PTSD-symptoms at baseline in comparison with completers, while others ( Foa et al., 1999 and Tarrier et al., 1999) found no differences at baseline. In other studies, no relationship between severity of symptoms and treatment outcome was reported ( Jaycox et al., 1998 and Munley et al., 1994). Also, no relationships between depression and treatment outcome were found ( Ehlers et al., 1998 and Jaycox et al., 1998), though a low suicide risk predicted better outcome ( Tarrier et al., 2000). In addition, a comorbid general anxiety disorder was found to be negatively related to treatment outcome ( Tarrier et al., 2000). (4) Neuroticism or personality pathology was related to the development or maintenance of PTSD ( Burgess & Holmstrom, 1979, Crocq & Crocq, 1987, McFarlane, 1988a and Noy, 1987) but was unrelated to treatment outcome ( Tarrier et al., 2000).