The Efficacy of Adding Short-Term Psychodynamic Psychotherapy to Antidepressants in the Treatment of Depression
** ABRIDGED **
Clinical Psychology Review · June 2020
Ellen Driessena,b,⁎, Jack J.M. Dekkerc, Jaap Peenc, Henricus L. Vand, Giuseppe Mainae,f, Gianluca Rossoe,f, Sylvia Rigardettof, Francesco Cunibertie,f, Veronica G. Vitriolg, Ramon U. Florenzanoh, Antonio Andreolii, Yvonne Burnandi, Jaime López-Rodríguezj,Valerio Villamil-Salcedoj, Jos W.R. Twiskk, Pim Cuijpersb
Highlights
Short-term psychodynamic psychotherapy (STPP) is a treatment for depression.
This effect can be related to STPP's specific treatment components.
Keywords: Depression, Short-term psychodynamic psychotherapy (STPP), Antidepressant medication, Combined treatment, Efficacy, Individual participant data meta-analysis
Abstract
Purpose: We examined the efficacy of adding short-term psychodynamic psychotherapy (STPP) to anti- depressants in the treatment of depression by means of a systematic review and meta-analysis of individual participant data, which is currently considered the most reliable method for evidence synthesis.
Results: A thorough systematic literature search resulted in 7 studies comparing combined treatment of anti- depressants and STPP versus antidepressant mono-therapy (n = 3) or versus antidepressants and brief supportive psychotherapy (n = 4). Individual participant data were obtained for all these studies and totaled 482 participants. Across the total sample of studies, combined treatment of antidepressants and STPP was found significantly more efficacious in terms of depressive symptom levels at both post-treatment (Cohen's d = 0.26, SE = 0.10, p = .01) and follow-up (d = 0.50, SE = 0.10, p < .001). This effect was most apparent at follow-up and in studies examining STPP's specific treatment efficacy. Effects were still apparent in analyses that controlled for risk of bias and STPP quality in the primary studies.
Conclusions: These findings support the evidence-base of adding STPP to antidepressants in the treatment of depression. However, further studies are needed, particularly assessing outcome measures other than depression and cost-effectiveness, as well as examining the relative merits of STPP versus other psychotherapies as added to antidepressants.
Introduction
Depression is a highly prevalent and potentially disabling disorder associated with major personal and societal costs (Kessler, 2012). Affecting more than 300 million people worldwide, depression is ranked as the single largest contributor to global disability by the World Health Organization (2017). Given the tremendous burden of disease, there is a great need for effective and efficient treatments for depression. Anti- depressant medications and different psychological therapies constitute the predominant treatments for depressive disorders (Marcus & Olfson, 2010). Concerning psychological treatments, there is a clinical tradition of short-term psychodynamic psychotherapies (STPPs) being used to treat depression. STPP is an empirically supported treatment for depression (Driessen et al., 2015).
Findings from ‘conventional’ meta-analyses suggest that combined treatment of antidepressant medication and psychotherapy in general is more efficacious than antidepressant mono-therapy in terms of depressive symptom reduction (Cuijpers et al., 2014; Karyotaki et al., 2016) and a review concludes that this might also be the case for STPP specifically (Fonagy, 2015). However, conventional meta-analyses, which are based on results extracted from published trial reports, are limited as they depend on the quality of the information in publications in which treatment effects can be overestimated. Therefore, their results can be biased (Stewart & Parmar, 1993).
Alternatively, individual participant data meta-analysis is a tech- nique to examine treatment effects by combining participant-level data of multiple trials. Individual participant data meta-analysis uses the same basic approach as any other well-conducted systematic review and meta-analysis. However, it involves collection of the original data from as many of the relevant trials worldwide as can be accessed. Individual participant data meta-analysis has several advantages over conventional meta-analysis, including the possibility to 1) account for missing data at the individual participant level, so that for instance intent-to-treat analyses can be conducted even though the original study reported completers-only analyses, 2) use the same statistical methods for imputing missing data and for conducting statistical analyses, thereby facilitating standardization across studies, 3) standardize outcomes across studies, for instance by using equal cut-off points on a depression outcome measure when the primary studies used different cut-offs, and 4) verify the results presented in the original studies, also by means of more sophisticated statistical techniques that were not available at time of publication in the case of older studies (Riley, Lambert, & Abo-Zaid, 2010). For these reasons, individual participant data meta-analysis provides the least biased and most reliable means of evidence synthesis and is considered the ‘gold standard’ in this regard (Stewart & Parmar, 1993).
To the best of our knowledge, to date, only one individual participant data meta-analysis has examined the efficacy of adding psychotherapy to antidepressants in the treatment of depression (Furukawa et al., 2018). This network meta-analysis specifically focused on the Cognitive-Behavioural Analysis System of Psychotherapy (CBASP) for persistent depression. It included two studies comparing combined treatment of antidepressants and CBASP versus antidepressant mono- therapy and reported a mean difference in depression severity at 12 weeks of 2.6 (1.6 to 4.3) Hamilton Depression Rating Scale (HAMD) points, favoring combined treatment.
We, therefore, conducted a systematic review and meta-analysis of individual participant data to examine the efficacy of adding STPP to antidepressants in the treatment of depression. We aimed to examine two types of comparisons: 1) combined treatment of antidepressants and STPP versus antidepressant mono-therapy, and 2) combined treatment of antidepressants and STPP versus combined treatment of antidepressants and brief supportive psychotherapy. The first comparison relates to the overall additional benefits of STPP added to anti- depressants in terms of both specific and non-specific treatment effects. Assuming that the efficacy of brief supportive psychotherapy is mainly determined by non-specific treatment factors as being empathically understood by a therapist or general advises how to deal with depressive symptoms, the second contrast relates to the specific treatment effects of STPP. We aimed to examine the efficacy of adding STPP to antidepressants in the treatment of depression at post-treatment as well as at follow-up.
Results
Included studies
For detailed results of the 2007 and 2014 literature searches, we refer the reader to Driessen et al. (2010, 2015). These searches identified 7 randomized comparisons of combined treatment of anti- depressants and STPP versus antidepressants with or without brief supportive psychotherapy (Burnand, Andreoli, Kolatte, Venturini, & Rosset, 2002; de Jonghe, Kool, van Aalst, Dekker, & Peen, 2001; Lopez Rodriguez, Lopez Butron, Vargas Terrez, & Villamil Salcedo, 2004; Maina, Rosso, Crespi, & Bogetto, 2007; Maina, Rosso, Rigardetto, Chiadò Piat, & Bogetto, 2010; Martini, Rosso, Chiodelli, De Cori, & Maina, 2011; Vitriol, Ballesteros, Florenzano, Weil, & Benadorf, 2009). Results of the literature search update that was performed June 19th, 2017 using the same search strategy are presented in Fig. 1. After re- moving duplicates, this literature search update resulted in 3641 re- cords, of which the majority (3233) was excluded in the first screening phase. A total of 408 titles were reviewed in full-text. Of these, none met the inclusion criteria for the present review. Finally, the database included 166 randomized clinical trials examining the efficacy of psychological treatments for depression published between January 1st, 2017 and January 1st, 2020. These were all reviewed in full-text, but none were identified as randomized comparisons of combined treatment of antidepressants and STPP versus antidepressants with or without brief supportive psychotherapy.
Thus, 7 studies met the inclusion criteria for the present review. Individual participant data were obtained for all these 7 studies (100.0%). The characteristics of the 7 included studies are described in Table 1. Three (42.9%) studies compared combined treatment of anti- depressants and STPP with antidepressant mono-therapy, while the other four studies (57.1%) compared combined treatment of anti- depressants and STPP with combined treatment of antidepressants and brief supportive psychotherapy. In all studies, participants were recruited from clinical samples (who actively sought help for depression first and were then asked to participate in the study). Depression inclusion criteria typically consisted of a DSM or ICD-10 depression diagnosis combined with an elevated HAMD score, though in one study an elevated HAMD score constituted the sole inclusion criterion for depression. In four studies (57.1%), the target group was adults with depression in general, while three studies (42.9%) included participants with specific anxiety disorder comorbidities. The study samples ranged from 20 to 167 participants. Follow-up assessments were conducted in 6 (85.7%) studies, with follow-up periods ranging from 6 months to 1 year post-baseline. All studies used the HAMD as primary outcome measure, with 6 (85.7%) studies assessing the 17-item version and 1 (14.3%) study assessing the 21-item version.
STPP was based on the principles described by Safran and Muran (2000), Andreoli (1999), de Jonghe, Rijnierse, and Janssen (1994),
Bellak (1993, 1994), Malan (1963, 1976), and Vitriol (2005). Treatment periods ranged from 10 to 26 weeks. Antidepressants included various selective serotonin reuptake inhibitors, though one study focused on a tricyclic antidepressant. In terms of the STPP quality criteria, therapists were adequately trained and treatment integrity was verified in all of the included studies. STPP was conducted according to a treatment manual in all but one study (85.7%; Lopez Rodriguez et al., 2004).
The 7 included studies totaled 482 participants, 238 (49.4%) in the combined antidepressants and STPP treatment conditions and 244 (50.6%) in the comparison conditions. The majority of the participants (70.0%) was female, with a mean age of 35.3 (SD = 9.9) years. The mean baseline 17-item HAMD score was 22.9 (SD = 7.9), indicating moderate symptom levels.
An overview of the risk of bias assessment is provided in Table 2. As can be seen in this table, all studies employed adequate random sequence generation and allocation concealment procedures. However, outcome assessors were not blind to treatment condition in two studies (28.6%) and for one other study (14.3%) the complete intent-to-treat data were not retained. Four studies (57.1%) scored negative on all four risk of bias criteria assessed.
Discussion
Findings
We conducted a systematic review and meta-analysis of individual participant data to examine the efficacy of adding STPP to anti- depressants in the treatment of depression. Across the total sample of seven studies that were identified by a thorough literature search, combined treatment of antidepressants and STPP was found to be significantly more efficacious than antidepressants with/without brief supportive psychotherapy. The size of this effect was small at post- treatment and moderate at follow-up. These results are in line with previous reviews suggesting increased treatment efficacy when adding psychotherapy in general (Cuijpers et al., 2014; Karyotaki et al., 2016) as well as STPP specifically (Fonagy, 2015) to antidepressant medication.
The overall findings appeared to be mostly driven by the subset of studies that contrasted combined treatment of antidepressants and STPP with combined treatment of antidepressants and brief supportive psychotherapy. Assuming that the efficacy of brief supportive psychotherapy is mainly determined by non-specific treatment factors as being empathically understood by a therapist or general advises how to deal with depressive symptoms, this contrast relates to STPP's specific treatment effects. In this set of studies, combined treatment of anti- depressants and STPP was found to be significantly more efficacious than combined treatment of antidepressants and brief supportive psy- chotherapy with a small effect size at post-treatment and a large effect size at follow-up.
The effect of adding STPP to antidepressants at follow-up was less apparent in the set of studies that contrasted combined treatment of antidepressants and STPP with antidepressant mono-therapy. In this subset of studies, small effects were found at both post-treatment and follow-up that were significantly superior to antidepressant mono- therapy when using unstandardized 17-item HAMD scores as outcome measure, but not when using HAMD z-scores as outcome measure. We think that this effect difference at follow-up is the consequence of the different studies that constitute the two subsets. For example, one of the studies comparing combined treatment of antidepressants and STPP versus antidepressant mono-therapy found no effect of adding STPP at both post-treatment (d = −0.04, SE = 0.24, p = .88) and follow-up (d = 0.04, SE = 0.20, p = .83; Maina et al., 2010). This study focused on comorbid major depression and obsessive-compulsive disorder and concluded that supplemental STPP has no significant clinical effect on such patients who are receiving adequate medications.
Strengths and limitations
This study has a number of strengths. First, individual participant data were obtained for all included studies. Thus, this meta-analysis did not suffer from data availability bias. Similarly, selection bias appeared to be limited as all studies employed adequate sequence generation and allocation concealment procedures. Second, by using individual participant data meta-analytic methods, we were able to improve the quality of the data and the analyses when compared to conventional meta- analysis methods. For instance, we worked with intent-to-treat samples that were not always reported on in the original study publications, and we facilitated standardization across studies by using the same statistical method for data-analysis, appropriately adjusting for baseline levels of depression in all studies (Twisk et al., 2018). Third, the included studies shared similarities in terms of sample recruitment, depression inclusion criteria, treatment format, and primary outcome measure.
However, this study also has a number of limitations. First, even though individual participant data could be obtained for all studies, the total number of participants included in this meta-analysis is modest (n = 482). Relatively few studies examined the efficacy of adding STPP to antidepressants. We think this reflects that psychodynamic therapy in general has been studied less extensively than other forms of psychotherapy for depression, such as cognitive behavioural therapy (CBT; e.g., Cuijpers et al., 2014). Second, and related, we cannot rule out the possibility that we have missed additional studies meeting the inclusion criteria, although we have tried to minimize this possibility by using an extensive search strategy and we were able to include a study that did not report the requisite data for effect size calculation in its publication and was therefore excluded from previous conventional meta-analyses (Driessen et al., 2010, 2015). Third, not all studies were free from detection bias and attrition bias. However, effects were still apparent in the sensitivity analyses that controlled for risk of bias in the primary studies. Fourth, although the studies shared similarities, they also differed, for instance, with regard to the STPP model used, the type of antidepressant examined, length of follow-up, and their focus on specific comorbidities. Therefore, this meta-analysis' results might not generalize to all STPP modes, antidepressant types, and participant groups. Fifth, this meta-analysis used depression level as the sole out- come measure. Although depression symptom level was specified a priori as the primary outcome measure (Driessen et al., 2018), examining additional outcome measures (e.g., anxiety, interpersonal functioning, quality of life) would have been desirable as these are important aspects of participant functioning too. In addition, examining cost-effectiveness would have been desirable as well to investigate whether the benefits in terms of efficacy outweigh the costs of adding STPP to antidepressant medication. However, this was not possible as outcome measures other than depression were not assessed consistently across the trials.
Clinical and research implications
The findings of this study suggest that people suffering from depression and their clinicians might expect lower depressive symptom levels when adding STPP to antidepressant medication. These benefits might be small at post-treatment and the largest benefits might be expected at follow-up. The finding that these benefits might be related to STPP's specific treatments effects as opposed to non-specific treatment factors, implicate the need for proper therapist training and supervision in order to capitalize on these specific STPP treatment effects. Collectively, these findings add to the evidence-base of adding STPP to antidepressants in the treatment of depression.
However, the findings of this study cannot be taken to imply that combined treatment of antidepressants and STPP should be considered the first choice treatment for individuals with depression, as this study does not speak to comparative efficacy with other depression treatments. Examining the relative merits of STPP versus other psychotherapies as added to antidepressants requires randomized comparisons of combined treatment of antidepressants and STPP versus combined treatment of antidepressants and another psychotherapy. The literature searches for our larger STPP for depression individual participant data meta-analysis project identified only one such study. This was a pilot study comparing combined treatment of antidepressants and STPP versus combined treatment of antidepressants and CBT, which pooled the two treatment conditions in its report because of the small sample size (n = 12; Perry, Banon, & Bond, 2020). One other study compared STPP and CBT as mono-therapies, but offered additional treatment with antidepressants to severely depressed participants (n = 129; Driessen et al., 2013). No significant treatment differences were found in this subgroup of severely depressed participants receiving combined treatment (post-treatment: Cohen's d = 0.21, 95% CI = −0.23 to 0.64, follow-up: d = 0.32, 95% CI = −0.15 to 0.79), but favored combined treatment with CBT and were large enough to be significant if replicated in a larger sample.
Considering the limitations of this study mentioned previously and the clinical importance of the research question, the field would benefit from further study of the efficacy of adding STPP to antidepressants in the treatment of depression. In our opinion, comparisons of combined treatment of antidepressants and STPP versus combined treatment of antidepressants and brief supportive psychotherapy are most relevant in this regard as they relate to STPP's specific treatment effects. Comparisons of combined treatment of antidepressants and STPP versus combined treatment of antidepressants and other psychotherapies (e.g., CBT) are also needed. Preferably, future study constitutes large-scale rigorously conducted randomized clinical trials that also assess out- come measures other than depression, including measures that facilitate cost-effectiveness analyses. As STPP might not be available for all people with depression due to scarcity of treatment resources and be- cause the addition of psychotherapy to antidepressant medication re- quires a financial investment, future research examining which participants benefit specifically from adding STPP to antidepressants in the treatment of depression is also needed.
Conclusion
We examined the efficacy of adding STPP to antidepressants in the treatment of depression by means of a systematic review and meta- analysis of individual participant data, which is currently considered the most reliable method for evidence synthesis. Across the total sample of seven studies that were identified by a thorough systematic literature search, adding STPP to antidepressants was found to be significantly more efficacious than antidepressants with/without brief supportive psychotherapy in terms of depressive symptom level at both post- treatment and follow-up. Effects were most apparent at follow-up and in studies that assessed STPP's specific treatment effects by including brief supportive psychotherapy in the comparison condition. Effects were still apparent in analyses that controlled for risk of bias and STPP quality in the primary studies. Although further study is needed, par- ticularly assessing cost-effectiveness and outcome measures other than depression, these findings support the evidence-base of adding STPP to antidepressants in the treatment of depression.
References
Andreoli, A. (1999). What we have learned about emergency psychiatry and the acute treatment of mental disorders. In M. De Clercq,, A. Andreoli,, & S. Lamarre, (Eds.). Emergency psychiatry in a changing world. Amsterdam: Elsevier.
Bellak, L. (1993). Manual de Psicoterapia Breve, Intensiva y de Urgencia. México: Manual Moderno.
Bellak, L. (1994). Manual para la Evaluación de las Funciones del Yo. México, Manual
Burke, D. L., Ensor, J., & Riley, R. D. (2017). Meta-analysis using individual participant data: One-stage and two-stage approaches, and why they may differ. Statistics in Medicine, 36, 855–875.
Burnand, Y., Andreoli, A., Kolatte, E., Venturini, A., & Rosset, N. (2002). Psychodynamic
psychotherapy and clomipramine in the treatment of major depression. Psychiatric Services, 53, 585–590.
Cuijpers, P., Karyotaki, E., Weitz, E., Andersson, G., Hollon, S. D., & van Straten, A. (2014). The effects of psychotherapies for major depression in adults on remission, recovery and improvement: A meta-analysis. Journal of Affective Disorders, 159, 118–126.
Cuijpers, P., Sijbrandij, M., Koole, S. L., Andersson, G., Beekman, A. T., & Reynolds, C. F.,
3rd. (2014). Adding psychotherapy to antidepressant medication in depression and anxiety disorders: A meta-analysis. World Psychiatry, 13, 56–67.
Cuijpers, P., van Straten, A., Warmerdam, L., & Andersson, G. (2008). Psychological treatment of depression: A meta-analytic database of randomized studies. BMC Psychiatry, 8, Article 36.
Driessen, E., Abbass, A. A., Barber, J. P., Connolly Gibbons, M. B., Dekker, J. J. M., ... Cuijpers, P. (2018). Which patients benefit specifically from short-term psychody-
namic psychotherapy (STPP) for depression? Study protocol of a systematic review and meta-analysis of individual participant data. BMJ Open, 8, Article e018900.
Driessen, E., Cuijpers, P., de Maat, S. C. M., Abbass, A. A., de Jonghe, F., & Dekker, J. J. M.
(2010). The efficacy of short-term psychodynamic psychotherapy for depression: A meta-analysis. Clinical Psychology Review, 30, 25–36.
Driessen, E., Hegelmaier, L. M., Abbass, A. A., Barber, J. P., Dekker, J. J. M., Van, H. L., ...
Cuijpers, P. (2015). The efficacy of short-term psychodynamic psychotherapy for depression: A meta-analysis update. Clinical Psychology Review, 42, 1–15.
Driessen, E., Van, H. L., Don, F. J., Peen, J., Kool, S., Westra, D., ... Dekker, J. J. M. (2013).
The efficacy of cognitive behavioral therapy and psychodynamic therapy in the outpatient treatment of major depression: A randomized clinical trial. American Journal of Psychiatry, 170, 1041–1050.
Fonagy, P. (2015). The effectiveness of psychodynamic psychotherapies: An update.
World Psychiatry, 14, 137–150.
Furukawa, T. A., Efthimiou, O., Weitz, E. S., Cipriani, A., Keller, M. B., Kocsis, J. H., ...
Schramm, E. (2018). Cognitive-behavioral analysis system of psychotherapy, drug, or their combination for persistent depressive disorder: Personalizing the treatment
choice using individual participant data network metaregression. Psychotherapy and Psychosomatics, 87, 140–153.
Higgins, J. P. T., Altman, D. G., & Sterne, J. A. C. (2011). Assessing risk of bias in included studies. In J. P. T. Higgins, & S. Green (Eds.). Cochrane Handbook for Systematic Reviews of Interventions [Version 5.1.0]https://handbook-5-1.cochrane.org/chapter_8/
8_assessing_risk_of_bias_in_included_studies.htm (accessed May 29th, 2019).
Higgins, J. P. T., Thompson, S. G., & Spiegelhalter, D. J. (2009). A re-evaluation of random-effects meta-analysis. Journal of the Royal Statistical Society, Series A, Statistics in Society, 172, 137–159.
Higgins, J. P., Whitehead, A., Turner, R. M., Omar, R. Z., & Thompson, S. G. (2001). Meta-
analysis of continuous outcome data from individual patients. Statistics in Medicine, 20, 2219–2241.
de Jonghe, F., Kool, S., van Aalst, G., Dekker, J., & Peen, J. (2001). Combining psy- chotherapy and antidepressants in the treatment of depression. Journal of Affective Disorders, 64, 217–229.
de Jonghe, F., Rijnierse, P., & Janssen, R. (1994). Psychoanalytic supportive psy-
chotherapy. Journal of the American Psychoanalytic Association, 42, 421–446.
Karyotaki, E., Smit, Y., Holdt Henningsen, K., Huibers, M. J., Robays, J., de Beurs, D., & Cuijpers, P. (2016). Combining pharmacotherapy and psychotherapy or monotherapy
for major depression? A meta-analysis on the long-term effects. Journal of Affective Disorders, 194, 144–152.
Kessler, R. C. (2012). The costs of depression. Psychiatric Clinics of North America, 35, 1–14.
Lopez Rodriguez, J., Lopez Butron, M. A., Vargas Terrez, B. E., & Villamil Salcedo, V. (2004). Double blind study with antidepressant, brief psychotherapy and placebo in patients with mild to moderate depression. Salud Mental, 27, 53–61.
Twisk, J., Bosman, L., Hoekstra, T., Rijnhart, J., Welten, M., & Heymans, M. (2018).
Different ways to estimate treatment effects in randomised controlled trials. Contemp. Clin. Trials Commun. 10, 80–85.
Maina, G., Rosso, G., Crespi, C., & Bogetto, F. (2007). Combined brief dynamic therapy
and pharmacotherapy in the treatment of major depressive disorder: A pilot study.
Psychotherapy and Psychosomatics, 76, 298–305.
Maina, G., Rosso, G., Rigardetto, S., Chiadò Piat, S., & Bogetto, F. (2010). No effect of adding brief dynamic therapy to pharmacotherapy in the treatment of obsessive- compulsive disorder with concurrent major depression. Psychotherapy and
Malan, D. H. (1963). A study of brief psychotherapy. London, Tavistock.
Malan, D. H. (1976). Toward a validation of dynamic psychotherapy. A replication. New York: Plenum.
Marcus, S. C., & Olfson, M. (2010). National trends in the treatment of depression from 1998 to 2007. Archives of General Psychiatry, 67, 1265–1273.
Martini, B., Rosso, G., Chiodelli, D. F., De Cori, D., & Maina, G. (2011). Brief dynamic therapy combined with pharmacotherapy in the treatment of panic disorder with concurrent depressive symptoms. Clinical Neuropsychiatry, 8, 204–211.
Perry, J. C., Banon, E., & Bond, M. (2020). Change in defense mechanisms and depression in a pilot study of antidepressive medications plus 20 sessions of psychotherapy for
recurrent major depression. The Journal of Nervous and Mental Disease. https://doi. org/10.1097/NMD.0000000000001112 (Epub ahead of print).
Riley, R. D., Lambert, P. C., & Abo-Zaid, G. (2010). Meta-analysis of individual participant data: Rationale, conduct, and reporting. BMJ, 340, c221.
Safran, J. D., & Muran, J. C. (2000). Negotiating the therapeutic alliance: A relational
treatment guide. New York: Guilford.
Stewart, L. A., & Parmar, M. K. B. (1993). Meta-analysis of the literature or of individual patient data: Is there a difference? Lancet, 341, 418–422.
Vitriol, V. (2005). In R. Florenzano,, K. Weil,, & C. Carvajal, (Eds.). Specialized program for
patients with trauma history at the mental health unit of Curicó hospital, in early devel- opmental trauma and adult psychopathology [in Spanish]. Santiago, Chile: Editorial Corporación de Promoción Universitaria.
Vitriol, V. G., Ballesteros, S. T., Florenzano, R. U., Weil, K. P., & Benadorf, D. F. (2009). Evaluation of an outpatient intervention for woman with severe depression and a history of childhood trauma. Psychiatric Services, 60, 936–942.