Does CBT have lasting effects in the treatment of PTSD after one year of follow-up ? A systematic review of randomized controlled trials

Introdução: Várias meta-análises anteriores documentaram a eficácia a curto prazo da terapia cognitivo-comportamental (TCC). No entanto, sua eficácia a longo prazo permanece desconhecida. O transtorno de estresse pós-traumático (TEPT) é uma doença crônica grave, debilitante e incapacitante. Objetivo: Estimar a eficácia a longo prazo da TCC no tratamento do TEPT, avaliando a manutenção do efeito após um ano de seguimento. Métodos: Realizamos uma revisão sistemática através de pesquisas nas bases de dados eletrônicas ISI Web of Science, PubMed, PsycInfo e Pilots. Incluímos estudos randomizados nos quais a TCC foi comparada com um grupo controle (lista de espera ou tratamento usual) em adultos com TEPT que relataram pelo menos um ano de seguimento da TCC. Resultados: A pesquisa identificou 2.324 estudos e 8 foram selecionados. A TCC mostrou-se eficaz no tratamento do TEPT no período pós-tratamento. A melhora nos sintomas de TEPT foi estatisticamente significativa em relação ao grupo controle. A melhora observada no grupo de tratamento ou grupo único (formado por ambos os grupos de tratamento e controle, que foi submetido à intervenção após algumas semanas na lista de espera) foi mantida no seguimento. Conclusão: Devido à ausência de grupo controle no período de follow-up em 6 dos 8 estudos incluídos nesta revisão, ainda não há base metodológica adequada para afirmar que a TCC tem efeitos duradouros no tratamento do TEPT. Nosso estudo encontrou graves deficiências metodológicas e a necessidade de preencher essa lacuna na literatura através de estudos com delineamentos robustos e sofisticados. Descritores: Transtorno de estresse pós-traumático, terapia cognitivo-comportamental, seguimento, efeitos duradouros. Abstract


Introduction
Post-traumatic stress disorder (PTSD) has a lifetime prevalence of about 6.8% in the general population. 1 It is a serious, debilitating, and when untreated, often chronic and disabling disease, severely compromising the quality of life of the individual. No anxiety disorder generates as many costs for the health systems and economies of so many countries as PTSD. 2 PTSD occurs in trauma-exposed individuals who present core symptoms of re-experiencing (e.g., intrusive thoughts or nightmares about the trauma), avoidance of traumarelated reminders, negative alterations in cognitions and mood (e.g., exaggerated blame of self or others for causing the trauma and difficulty experiencing positive affect), and alterations in arousal and reactivity (e.g., sleep disturbance and irritability or aggression). 3 Cognitive-behavioral therapy (CBT) is the most extensively tested form of psychotherapy. 4 Most guidelines for PTSD treatment consider psychological treatments with a focus on trauma, including CBT, as a first treatment option, and pharmacological treatment as an adjunct or second option. 5 The short-term efficacy of CBT in the treatment of PTSD is well documented in several meta-analyses. 6,7 Yet, as far as we know, no meta-analysis has evaluated whether the effects of CBT in the treatment of PTSD are long-lasting. The development and dissemination of effective treatments that have lasting effects is imperative. 8 Generally, for the effects of a treatment to be considered long-lasting, it is necessary that the changes produced are stable over the long term, extending beyond the end of the intervention period. 9 Regarding anxiety disorders, we found only one metaanalysis evaluating the effect of long-term psychotherapies.

Literature search
We performed electronic searches in four large databases: ISI Web of Science, PubMed, PsycInfo and Pilots. The following terms were combined: (PTSD OR "stress disorder") AND ("cognitive behavio* therap*" OR CBT OR "behavio* therap*" OR "cognitive therap *") AND ("follow-up" OR followup OR "follow up"). We also performed manual searches of the references of previous meta-analyses and the articles selected for the study. Searches were carried out until July 10, 2016. No filters were used to limit languages or years.

Inclusion and exclusion criteria
Randomized studies of adults with PTSD, in which CBT was compared to a control group (waiting list or usual care) and that reported at least one year of CBT follow-up, were selected. In addition, the following inclusion criteria were adopted: 1) studies in which the subjects recruited fulfilled the diagnostic criteria for PTSD according to a structured diagnostic interview; 2) studies in which cognitive restructuring was a To keep heterogeneity as low as possible, we followed the methodological recommendations of Cuijpers et al. 4 and included only studies that used as a control group a waiting list or TAU group. TAU was defined as any treatment that patients would normally receive, provided it was not considered a structured type of psychotherapy.

Evaluation of the methodological quality of the studies
We assessed the methodological quality of the followup period of the included studies using an adaptation of the Cochrane Collaboration bias risk assessment tool. 11 In addition to the original proposed criteria, we added the following criteria: treatment description (or reference). Each study included in the review was classified as either low risk, high risk or unclear risk of bias in each of the criteria used.
The assessment of methodological quality did not consider the data reported after treatment, but was based on the data reported in the follow-up period, as this was the focus of this review. We performed a critical analysis of these studies but did not use the findings as an exclusion criterion, so even if we found a study classified as having a "high risk" of bias, it was included anyway. Figures were produced to illustrate the outcome of the review using the software Review Manager 5. 12

Results
Our search identified 2,324 studies. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart, 13 which describes the inclusion process and the reasons for exclusion of the studies, is presented in Figure 1. A total of 8 studies [14][15][16][17][18][19][20][21] met the inclusion criteria for this systematic review.
The studies were altered between their initial design and the period when the follow-up assessment began, so that six of the eight studies failed to have a control group at some point in the follow-up period. For this reason, we chose to present the characteristics of the selected studies in two stages: post-treatment period (Table 1) and follow-up period ( Table 2). Follow-up less than 12 monts (17) No follow-up (2) No focus on PTSD (4) Non-randomized controlled study (9) Control group was not waiting list or TAU (12) Other reasons therapy. [16][17][18][19]21 Two studies used only exposure therapy, 14,20 and one study used cognitive processing therapy. 15 In five studies, the control group comprised a waiting list, [15][16][17][18]21 while two studies used TAU. 14,20 Nacasch et al. 20 defined TAU as psychodynamic therapy and/or medication or counseling, and Asukai et al. 14 as pharmacotherapy and supportive counseling. One study used brief treatment, 19 which offered the same breathing and psychoeducation training components as the CBT program, but without the cognitive restructuring.
The CBT groups showed a more significant reduction in PTSD symptoms in the post-treatment period   The significant reduction in PTSD symptoms observed in the intervention group (and in the control group receiving the intervention) after treatment was also observed in the single group created in the follow-up period. to obtain the random sequence, and used procedures so that the person in charge of selecting the participants did not know, a priori, the allocation group. In the case of Nacasch et al., 20 this information was not available.
All the other six studies that did not use a control group in the follow-up period were considered as having a high risk of bias in respect to losses for the outcome of interest in this review. Considering the two studies with control groups in the follow-up period, only Mueser et al. 19 presented results for all primary outcomes of interest. All studies provided a good description of the treatment or provided references to it.

Discussion
To our knowledge, this is the first systematic review   Only one study 17 reports the rate of relapse after the intervention. Given that PTSD is a chronic, long-lasting disorder, 2 studies should include not only a longer followup (at least greater than 12 months), but also reports on the rate of relapse after the intervention. Thus, the real effects over time as well as the cost-benefit of the interventions could be better evaluated.
There is no data in the literature yet on the relapse and recurrence of PTSD after psychotherapy.
In depression, there are some preliminary data evaluating and discussing relapse and recurrence of the disorder. 25 Beshai et al. 25

Limitations
The present systematic review included only four databases, although those selected are the key ones.
In addition, only one review author carried out the selection of the articles; doubts were discussed with the three other authors, and any disagreements were settled by consensus. Also, no experts were contacted to identify unpublished articles.

Conclusion
It is imperative to consider whether a treatment has sustained efficacy. A treatment that produces an initial response or even a response that lasts for about six months after its completion may still not be an effective treatment in a disorder such as PTSD, 22

Disclosure
No conflicts of interest declared concerning the publication of this article.