Contrary to our hypotheses, we did not find that a therapy developed to provide a dual focus on a range of PDs and substance dependence retained or reduced symptoms better for this group of participants or that a therapy focused mostly on addiction was better for those without those PDs. Quite the opposite, we found that IDC provided more sustained reduction of psychiatric symptoms or dysphoric affect than did DFST for three of the four PDs evaluated. The superiority of IDC could not be attributed to differences in therapist skill between the conditions. In fact, PD participants receiving DFST improved less despite independent fidelity ratings that they were being treated by more competent psychotherapists.
Although our prior trial of DFST with methadone maintained PD patients (Ball, 2007
) had promising substance use outcomes, it was less effective in reducing dysphoria than a 12-step facilitation therapy that has overlap with IDC. Our trial with homeless substance using PD clients (Ball et al, 2005
) suggested that DFST was less effectively utilized by some clients with more severe PDs than group counseling using IDC topics. These two trials and our current findings suggest that PD patients with significant paranoia, affect instability, impulsivity, rigidity, and avoidance may find addiction-focused discussions more stabilizing than an insight- and change-oriented focus on their maladaptive schemas and coping styles. An alternative explanation is that the addiction-focused topics discussed in IDC were more similar to what patients had been exposed in prior treatments, the standard care in their current program, or self-help meetings. The greater familiarity of the IDC material may allow better consolidation of therapeutic content and skills. In contrast, the newness (and possibly anxiety provoking nature) of the schema material may interfere with the cognitive-affective integration necessary for symptom improvement.
This study had several limitations. First, the substance-free status of most participants on admission and the controlled residential environment made substance use an irrelevant outcome variable. This is important to note because this was the one outcome that DFST outperformed the standard addiction counseling approach in the first clinical trial involving methadone maintained patients (Ball, 2007
). In addition, the three outcomes assessed in the current study were all self-report measures of personality-related symptoms or problems and did not involve more objective, expert, or observational behavior ratings. Finally, it should be noted that neither IDC nor DFST were particularly effective as once weekly individual psychotherapies in preventing the very high drop out that is seen in a challenging 24 hour/7 day residential addiction treatment environment.
Related to this issue, the most significant limitations related to treatment exposure, duration, and focus. Our low rates of successful treatment completion and research assessment follow-ups are common problems in PD clinical trials (Blum et al, 2008
; Verheul et al, 2003
). For reasons related to what happened (i.e., relapse, re-arrest) when most patients dropped out of residential treatment, significant symptom improvement can only be assumed for participants who completed most of their assigned therapy. On a related note, 6 months of weekly therapy is probably insufficient to result in sustained changes in maladaptive personality or psychological indicators. We chose this duration because: 1) 6-months is the minimum necessary for substance use and psychosocial improvements in long-term residential programs (Hubbard et al, 1997
); 2) a meta-analysis of PD treatments (Perry et al, 1999
) found a median of 28 weeks of intensive treatment was associated with significant symptom improvement; 3) both DFST and IDC manuals were designed as 6-month interventions. Given the above noted differences in familiarity with therapy content, acute psychiatric symptom reduction may be more achievable in 6 months of IDC than DFST. A clinical trial that found schema therapy more effective than transference focused therapy for Borderline PD (Geisen-Bloo et al, 2006
) involved 2-year duration therapies, and the treatments for Borderline PD with the most empirical support (Bateman & Fonagy, 1999
; Linehan et al, 1991
) have durations exceeding one year, an intensive outpatient focus, and integrate different orientations or modalities. Finally with regard to therapeutic focus, the developers of schema therapy (Young et al, 2003
) have argued that the original model may not be effective for Borderline and other PDs characterized by very high avoidance or rigidity, which may describe our sample of patients. A revised schema-based approach called mode therapy has been proposed and was found to be effective in a clinical trial with Borderline PD (Geisen-Bloo et al, 2006
Clinicians and experts believe there is a the need for highly specialized, integrative, or dual focus therapies for substance abuse and PDs despite very limited empirical evidence (Conrod & Stewart, 2005
; Ekleberry, 2009
; Kienas & Foerster, 2008
; van den Bosch & Verheul, 2007
). Our findings do little to support such beliefs, at least for the severely compromised substance users we have tested in three service settings. The majority of evidence supporting the use of integrative or dual focus cognitive behavioral treatment models (Conrod & Stewart, 2005
) has come either from studies involving no comparison group or an uncontrolled treatment-as-usual typically of unknown quality and variable quantity. The delivery of an evidence-based therapy by an experienced psychotherapist who specifically targets substance dependence may provide acute symptom management over which a dual focus model cannot improve significantly. Further research on both addiction-focused and dual-focused therapies is needed to improve outcomes for this challenging population and to determine if the increased time and cost for training and implementing a complex, integrative therapy model for Axis I-II patients is justified. In addition to the numerous treatment models tested for Borderline PD (Bateman & Fonagy, 1999
; Blum et al, 2008
; Clarkin et al, 2007
; Davidson et al, 2006
; Giesen-Bloo et al, 2006
; Gregory et al, 2008
; Hoglend, 1993
; Linehan et al, 1991
; Ryle & Golynkina, 1990), several randomized trials have suggested that once or twice weekly outpatient psychodynamic or cognitive behavioral models may be effective for the broader group of PDs (Arnevik et al, 2010
; Leichsenring & Leibing, 2003
; Svartberg et al, 2004
; Verheul & Herbrink, 2007
). It remains an empirical question whether these models can be adapted more effectively than schema therapy for use with substance dependent patients.