Eficacia del EMDR
El EMDR tiene una amplia base de reportes de casos publicados e investigación controlada que soportan a esta metodología como un tratamiento validado empíricamente para tratar trauma.
Las directrices de Práctica Clínica para el Tratamiento de Pacientes con Trastorno por Estrés Agudo y Trastorno por Estrés Postraumático de la American Psychiatric Association Han designado al EMDR como un Tratamiento Efectivo para dichos trastornos (17)
Las directrices de Práctica Clínica para el manejo de Estrés Postraumático del Departamento de Asuntos para Veteranos del Departamento de Defensa de los Estados Unidos han designado al EMDR como un Tratamiento Efectivo para tratar el Estrés Postraumático. Con nivel de recomendación "A": Fuerte recomendación de que la intervención con esta metodología es siempre indicada y aceptable. (1)
Las directrices de actuales del Instituto Nacional de Salud e Investigación Médica de Francia han designado al EMDR como un Tratamiento Efectivo para tratar a las víctimas de trauma. (2)
Las recomendaciones regionales de tratamiento para trastornos de ansiedad de Suecia han designado al EMDR como un Tratamiento Efectivo para tratar TEPT (3)
Las directrices de actuales de Cuidados en Salud Mental de Holanda han designado al EMDR como un Tratamiento Efectivo para tratar el TEPT. (4)
Las directrices actuales de tratamiento del Departamento de Salud de Irlanda han designado al EMDR como un Tratamiento Efectivo para tratar a las víctimas de Trauma.(5)
Las directrices actuales de tratamiento del Departamento de Salud del Reino Unido 6 y el Consejo Nacional Israelí de Salud Mental 7 han designado al EMDR como un Tratamiento Efectivo para tratar el TEPT y a víctimas del terror.
Las directrices actuales de tratamiento de la International Society for Traumatic Stress Studies (ISTSS) han designado al EMDR como un Tratamiento Efectivo para tratar el Trastorno por Estrés Postraumático (TEPT). (8)
1998. Meta-análisis de todos los tratamientos psicológicos y de farmacoterapia para tratar el TEPT. Van Etten & Taylor revisan 59 estudios. Concluyen: "EMDR es efectivo para el tratamiento del TEPT, y es más eficiente que otros tratamientos." (9)
De acuerdo a la Fuerza de Trabajo de la División Clínica de la American Psychological Association, el EMDR es una metodología validada empíricamente para tratar TEPT (10)
Nota Importante: En el año de 1997, el Consejo Directivo de la ISTSS inició el proyecto de desarrollar un grupo de directrices para tratamiento, basadas en una extensiva revisión de la literatura clínica e investigaciones, preparada por expertos en el campo. Así como en estudios bien controlados que cumplieran con los criterios de la Agency of Health Care Policy and Research Classification of Level of Evidence.
En el años 2000 se publicaron dichas directrices(11), con la intención de informar a los clínicos de todo el mundo de cuales eran las mejores metodologías para tratar individuos con el diagnóstico de TEPT (niños, adolescentes y adultos), que es una condición psicológica seria que puede ocurrir como resultado de experienciar un evento traumático.
Los pacientes con TEPT usualmente tienen al menos otro trastorno psiquiátrico. El departamento de epidemiología de los Estados Unidos, encontró que el 80 % de los pacientes con TEPT sufren de depresión, otro trastorno de ansiedad o dependencia/abuso químico.
Por lo que en el desarrollo de estas directrices, la fuerza de trabajo de la ISTSS reconoció que el TEPT es frecuentemente acompañado de otras condiciones psicológicas y que esa comorbidad requiere de sensibilidad clínica, atención, y evaluación diagnóstica durante todo el proceso del tratamiento.
Las aproximaciones terapéuticas que obtuvieron las más altas calificaciones (niveles A y B) *on EMDR y Terapia Cognitiva Conductualen su modalidad de exposición(exposure): inundación/imaginal/envivo/prolongada/dirigida.
Tres estudios(12) (13) (14) han indicado la eliminación del Diagnóstico de TEPT en un rango del 77 al 99% de los pacientes después de 3 a7 sesiones de 90 min.
Otros estudios han mostrado decrementos significativos en un amplio rango de los síntomas del TEPT después de 2-3 sesiones. (15)
Los efectos del tratamiento con EMDR se mantienen. Un estudio reporta 84% de remisión del diagnóstico de TEPT en un seguimiento a 15 meses. (16)
1 Department of Veterans Affairs & Department of Defense (2004). VA/DoD CLINICAL PRACTICE GUIDELINES FOR THE MANAGEMENT OF POST- TRAUMATIC STRESS. www.oqp.med.va.gov/cpg/ptsd
2 INSERM (2004). Psychotherapy: An evaluation of three approaches. French National Institute of Health and Medical Research. Paris, France.
3 Sjoblom, P.O., Andréewitch, S. Bejerot, S., Mortberg, E (2003). Regional treatment recommendation for anxiety disorders. Stockholm: Medical Program Commmmittee/Stockholm City Council, Sweden.
4 Dutch National Steering Committee Guidelines Mental Health Care (2003). Multidisciplinary Guidelines Anxiety Disorders. Quality Institute Health Care CBO/Trimbos Institute. Utrecht, Netherlands.
5 CREST (2003). The management of PTSD in adults. A publication of the Clinical Resource Efficiency Support team of the Northern Ireland Department of Health, Social Services and Public Safety, Belfast.
6 United Kingdom Department of Health. (2001). Treatment choice in psychological therapies and counseling evidence based clinical practice guidelines. London: Author WEB:
7 Bleich, A. Kotler, M., Kutz, E., & Shaley, A. (2002). A position paper of the (Israeli) National Council for Mental Health: Guidelines for the assessment and professional intervention with terror victims in the hospital and in the community.
8 Chemtob, Tolin, van der Kolk & Pitman (2000). EMDR in Edna A. Foa, Terence M. Keane & Matthew J. Friedman [Eds.]. Effective treatments for PTSD: Practice Guidelines from the ISTSS. New York: Guilford Press, p.139-155, 155, 333-335.
9 Van Etten, M.L. & Taylor, S. (1998). Comparative efficacy of treatments for posttraumatic stress disorder: A meta- analysis. Clinical Psychology & Psychotherapy, 5, 126-144.
10 Chambless, D.L., et al. (1998). Update of empirically validated therapies, II. The Clinical Psychologist, 51, 3-16.
11 Effective treatments for PTSD: Practice Guidelines from the ISTSS. New York: Guilford Press, p.139-155, 155, 333-335.
12 Lee, C & Gavriel, H., Drummond, P., Richards, J. & Greenwald, R. (2002). Treatment of post-traumatic stress disorder: A comparison of stress inoculation training with prolonged exposure and EMDR. Journal of Clinical Psychology, 58, 1071-1089.
13 Marcus, S., Marquis, P. & Sakai, C. (1997). Controlled study of treatment of PTSD using EMDR in an HMO setting. Psychotherapy, 34, 307-315.
14 Rothbaum, B.O. (1997). A controlled study of EMDR for PTSD sexual assault victims.Bulletin of the Menninger Clinic, 61, 317-334.
15 Ironson, G.I., Freund, B., Strauss, J.L., & Williams, J. (2002) A comparison of two treatmentsfor traumatic stress: A community based study of EMDR and prolonged exposure. Journal of Clinical Psychology, 58, 113-128.
16 Wilson, S.A., Becker, L.A., & Tinker, R.H. (1995) Fifteen-month follow-up of EMDR treatment for PTSD and psychological trauma. Journal of Consulting and Clinical Psychology, 65, 928-937.
17. APA: Practice Guidelines for the Treatment od Patients with Acute Stress Disorder and PTSD (November 2004)
Poblaciones Tratadas con EMDR en Estudios Controlados
Estudios de Neurofisiología
Rauch, van der Kolk, y colegas (1996) condujeron estudios con la metodología de emisión de positrones en pacientes con TEPT.
Los pacientes fueron expuestos a narrativas vívidas y detalladas de lo que ellos habían escrito acerca de sus propias experiencias traumáticas.
Los pacientes mostraron un aumento de la actividad solo en el hemisferio derecho, en las áreas más involucradas con la excitación emocional.
También mostraron aumento de la actividad en la corteza visual derecha, cuando reportaban sus flashbacks (vívidas memorias).
Quizá lo más significativo fue que el área de Broca – la parte del hemisferio izquierdo responsable de convertir las experiencias personales en lenguaje “se apagó”. Estos hallazgos indican que los síntomas del TEPT se reflejan en cambios de la actividad cerebral.(1)
En un estudio publicado en 1999, los doctores Levin, Lazrove y van der Kolk notaron cambios neurofisiológicos, utilizando el método SPECT para escanear el funcionamiento del cerebro de pacientes antes y después de recibir EMDR.
Esta es una evidencia preliminar de que puede haber cambios en los patrones de activación cerebral después de un tratamiento efectivo.
Se llevó a cabo un escaneo con el método SPECT antes y después de recibir tratamiento con EMDR.
Los hallazgos indicaron cambios metabólicos después de EMDR en dos regiones específicas del cerebro.
Primero, hubo un incremento en la actividad bilateral de la circunvolución cingular anterior .
Esta área modera la experiencia de amenazas reales contra percibidas.
Después del tratamiento con EMDR los pacientes diagnosticados clínicamente con TEPT dejaron de estar hipervigilantes.
Segundo, hubo un incremento en el metabolismo del lóbulo frontal, lo que puede indicar una mejoría en la habilidad de dar sentido a la estimulación sensorial recibida.(2)
Para mayor información sobre la evidencia científica de EMDR visitar:
Secciones de: Efficacy. Research y Trauma Research
1 Rauch, S., van der Kolk, B. A., Fisler, R., Alpert, N. M., Orr, S. P., Savage, C.R., Fischman, A. J., Jenike, M. A., & Pitman, R. K. (1996). Symptom provocation study of post traumatic stress disorder using positron emission tomography and script-drive imagery. Archives of General Psychiatry, 53, 380-387.
2 (Levin, Patti, Lazrove, Steven y van der Kolk, Bessel, 1999. “What psychological testing and neuroimaging tell us about the treatment of posttraumatic stress disorder by eye movement desensitization and reprocessing.” Journal of Anxiety Disorders, Vol. 13, No. 1-2, pp. 159-172.)
Investigaciones y lecturas
International Treatment Guidelines
EMDR is recommended as an effective treatment for trauma.
EMDR was listed as an effective and empirically supported treatment for PTSD, and was given an AHCPR "A" rating for adult PTSD. This guideline specifically rejected the findings of the previous Institute of Medicine report, which stated that more research was needed to judge EMDR effective for adult PTSD. With regard to the application of EMDR to children, an AHCPR rating of Level B was assigned. Since the time of this publication, three additional randomized studies on EMDR have been completed (see below).
EMDR and CBT were stated to be the treatments of choice for trauma victims.
Trauma-focused CBT and EMDR were stated to be empirically supported treatments for choice for adult PTSD
Best evidence of efficacy was reported for EMDR, exposure, and stress inoculation
EMDR has been compared to numerous exposure therapy protocols, with and without CT techniques. It should be noted that exposure therapy uses one to two hours of daily homework and EMDR uses none. The most recent meta-analyses are listed here.
"Trauma focused cognitive behavioural therapy and eye movement desensitisation and reprocessing have the best evidence for efficacy at present and should be made available to PTSD sufferers."
EMDR is equivalent to exposure and other cognitive behavioral treatments and all "are highly efficacious in reducing PTSD symptoms."
EMDR is equivalent to exposure and other cognitive behavioral treatments.
A comprehensive meta-analysis reported the more rigorous the study, the larger the effect.
"Results indicate efficacy of EMDR when effect sizes are based on comparisons between EMDR and non-established trauma treatment or no-treatment control groups, and incremental efficacy when effect sizes are based on comparisons between EMDR and established (CBT) trauma treatment."
"Results suggest that in the treatment of PTSD, both therapy methods tend to be equally efficacious."
Randomized Clinical Trials
Twelve sessions of EMDR eliminated post-traumatic stress disorder in 77.7% of the multiply traumatized combat veterans studied. There was 100% retention in the EMDR condition. Effects were maintained at follow-up. This is the only randomized study to provide a full course of treatment with combat veterans. Other studies (e.g., Boudewyns/Devilly/Jensen/Pitman et al./Macklin et al.) evaluated treatment of only one or two memories, which, according to the International Society for Traumatic Stress Studies Practice Guidelines (2000), is inappropriate for multiple-trauma survivors. The VA/DoD Practice Guideline (2004) also indicates these studies (often with only two sessions) offered insufficient treatment doses for veterans.
"EMDR is effective in reducing earthquake anxiety and negative emotions (e.g. PTSD, grief, fear, intrusive thoughts, depression, etc) resulting from earthquake experience. Furthermore, results show that, improvement due to EMDR was maintained at a one month follow up."
EMDR was found to be an effective treatment for children with disaster-related PTSD who had not responded to another intervention.
EMDR treatment of disturbing life events (small "t" trauma) was compared to active listening, and wait list. EMDR produced significantly lower scores on the Impact of Event Scale (mean reduced from "moderate" to "subclinical") and a significantly smaller increase on the STAI after memory recall.
EMDR treatment resulted in lower scores (fewer clinical symptoms) on all four of the outcome measures at the three-month follow-up, compared to those in the routine treatment condition. The EMDR group also improved on all standardized measures at 18 months follow up (Edmond & Rubin, 2004, Journal of Child Sexual Abuse).
Combination of qualitative and quantitative analyses of treatment outcomes with important implications for future rigorous research. Survivors' narratives indicate that EMDR produces greater trauma resolution, while within eclectic therapy, survivors more highly value their relationship with their therapist, through whom they learn effective coping strategies.
Employees who had experienced "person-under-train accident or had been assaulted at work were recruited." Six sessions of EMDR resulted in remission of PTSD in 67% compared to 11% in the wait list control. Significant effects were documented in Global Assessment of Function (GAF) and Hamilton Depression (HAM-D) score. Follow-up: Högberg, G. et al. (2008). Treatment of post-traumatic stress disorder with eye movement desensitization and reprocessing: Outcome is stable in 35-month follow-up. Psychiatry Research. 159, 101-108.
Both EMDR and prolonged exposure produced a significant reduction in PTSD and depression symptoms. This is the only research comparing EMDR and exposure therapy that equalized homework. The study found that 70% of EMDR participants achieved a good outcome in three active treatment sessions, compared to 29% of persons in the prolonged exposure condition. EMDR also had fewer dropouts.
Both EMDR and CBT produced significant reduction in PTSD and behavior problems. EMDR was significantly more efficient, using approximately half the number of sessions to achieve results.
"An effect for EMDR was identified on primary outcome and process measures including the Child Post-Traumatic Stress – Reaction Index, clinician rated diagnostic criteria for PTSD, Subjective Units of Disturbance and Validity of Cognition scales. All participants initially met two or more PTSD criteria. After EMDR treatment, this decreased to 25% in the EMDR group but remained at 100% in the wait-list group."
Funded by Kaiser Permanent, follow-up evaluation indicates that a relatively small number of EMDR sessions result in substantial benefits that are maintained over time.
Both EMDR and exposure therapy plus cognitive restructuring (with daily homework) produced significant improvement. EMDR was more beneficial for depression, and social functioning, and required fewer treatment sessions. Subsequent reevaluation of the data indicated that "For pre- to post-treatment IES mean change score, EMDR patients also appeared to have had better treatment outcome than E+CR patients" and EMDR therapy was a predictor of positive outcome: Karatzias, A., Power, K. McGoldrick, T., Brown, K., Buchanan, R., Sharp, D. & Swanson, V. (2006). Predicting treatment outcome on three measures for post-traumatic stress disorder. Eur Arch Psychiatry Clin Neuroscience, 20, 1-7.
Three 90-minute sessions of EMDR eliminated post-traumatic stress disorder in 90% of rape victims.
In this NIMH funded study both treatments were effective: "An interesting potential clinical implication is that EMDR seemed to do equally well in the main despite less exposure and no homework. It will be important for future research to explore these issues."
Seminal study appeared the same year as first controlled studies of CBT treatments. Three-month follow-up indicated substantial effects on distress and behavioral reports. Marred by lack of standardized measures and the originator serving as sole therapist.
The addition of three sessions of EMDR resulted in large and significant reductions of memory-related distress, and problem behaviors at 2-month follow-up.
The only randomized study to show exposure statistically superior to EMDR on two subscales (out of 10). This study used therapist assisted "in vivo" exposure, where the therapist takes the person to previously avoided areas, in addition to imaginal exposure and one hour of daily homework (@ 50 hours). The EMDR group used only standard sessions and no homework.
EMDR was superior to both control conditions in the amelioration of both PTSD symptoms and depression. Upon termination of therapy, the EMDR group continued to improve while the Fluoxetine participants again became symptomatic.
All treatments led to significant decreases in PTSD symptoms for subjects in the treatment groups as compared to those on a waiting list, with a greater reduction in the EMDR group, particularly with respect to intrusive symptoms. In the 2-3 weeks of the study, 40-60 additional minutes of daily homework were part of the treatment in the other two conditions.
Twenty-six children (average age 10.4 years) with behavioral problems were randomly assigned to receive either 4 sessions of EMDR or CBT. Both were found to have significant positive effects on behavioral and self-esteem problems, with the EMDR group showing significantly larger changes in target behaviors.
Follow-up at 15 months showed maintenance of positive treatment effects with 84% remission of PTSD diagnosis.
A comprehensive group intervention with 124 children, who experienced disaster related trauma during a massive flood utilizing a one session group protocol. Significant differences were obtained and maintained at 3-month follow up.
This field study explores the effectiveness of EMDR and the level of post-traumatic reactions in a post-emergency context on 22 children victims of an earthquake. The results show that EMDR contributed to the reduction or remission of PTSD symptoms and facilitated the processing of the traumatic experience
A group intervention of EMDR was provided to 236 schoolchildren exhibiting PTSD symptoms 30 days post-incident. At four-month follow up, teachers reported that all but two children evinced a return to normal functioning after treatment.
A study of Hurricane Andrew survivors found significant differences on the Impact of Event Scale and subjective distress in a comparison of EMDR and non-treatment condition.
36 children and adolescents ranging in age from 1 year 9 months to 18 years 1 month were assessed at intake, post-waitlist/pretreatment, and at follow up. EMDR treatment resulted in significant improvement, demonstrating that children younger than 4 years of age showed the same benefit as the school-age children.
A study of 200 children treated with a group protocol after a flood in Mexico indicates that one session of treatment reduced trauma symptoms from the severe range to low (subclinical) levels of distress. Data from successful treatment at other disaster sites are also reported.
"In this study the EMDR-IGTP was used with 16 bereaved children after a human provoked disaster in the Mexican State of Coahuila in 2006. Results showed a significant decrease in scores on the Child's Reaction to Traumatic Events Scale that was maintained at 3-month follow-up."
Data reported on a representative sample of 1500 earthquake victims indicated that five sessions of EMDR successfully eliminated PTSD in 92.7% of those treated, with a reduction of symptoms in the remaining participants.
In this delayed treatment comparison, over half of the participants moved from clinical to normal levels on the Impact of Events Scale, and all but 3 showed at least partial symptom relief on several measures at 1-3 m following a single EMDR session.
Clients made highly significant positive gains on a range of outcome variables, including validated psychometrics and self-report scales. Analyses of the data indicate that EMDR is a useful treatment intervention both in the immediate aftermath of disaster as well as later.
60 railroad employees who had experienced fatal grade crossing accidents were evaluated for workshop outcomes, and for the additive effects of EMDR treatment. Although the workshop was successful, in this setting, the addition of a short session of EMDR (5-40 minutes) led to significantly lower, sub clinical, scores which further decreased at follow up.
In a multi-site study, EMDR significantly reduced symptoms more often than the CBT treatment on behavioral measures, and on four of five psychosocial measures. EMDR was more efficient, inducing change at an earlier stage and requiring fewer sessions. Positive recall of the deceased was significantly greater post treatment in the EMDR condition.
Results indicate that the EMDR approach can be effective in a group setting, and in an acute situation, both in reducing symptoms of posttraumatic and peritraumatic stress and in "inoculation" or building resilience in a setting of ongoing conflict and trauma.
Adaptive Information Processing, and EMDR Procedures, The Adaptive Information Processing model (Shapiro, 2001, 2002, 2007) is used to explain EMDR's clinical effects and guide clinical practice. This model is not linked to any specific neurobiological mechanism since the field of neurobiology is as yet unable to determine this in any form of psychotherapy (nor of most medications). This section includes literature to provide an overview of the model and procedures, as well as selected research and case reports that demonstrate the predictive value of the model in the treatment of life experiences that appear to underlie a variety of clinical complaints.
Processing of etiological disturbing memories, triggers and templates resulted in complete remission of Major Depressive Disorder in two teenagers. Treatment duration was 3-7 sessions and effects were maintained at follow-up.
20 EMDR sessions that focused on reprocessing the memories seemingly at the foundation of the pathology, along with triggers and future templates resulted in a complete remission of BPD, including symptoms of affect dysregulation, as measured on the Inventory of Altered Self Capacities.
Seven consecutive cases were treated with up to three sessions of EMDR. Complete remission of BDD symptoms were reported in five cases with effects maintained at one- year follow-up.
As predicted by AIP, the processing of etiological events, triggers and memory templates was sufficient to alleviate the diagnosis without the use of therapist-assisted in vivo exposure.
Four subjects were evaluated using a single case design with multiple baselines Results indicate that subsequent to targeting the experiential contributors, at posttreatment and at 2 months follow-up, all four participants no longer presented with GAD diagnosis.
EMDR processing of experiential contributors to bonding disruption, in addition to current triggers, and a memory template of an alternative/problem free pregnancy and birth resulted in the repair of maternal bonding, analogous to the positive findings with the repair of disrupted attachment.
EMDR treatment of four consecutive cases of ORS whose pathological symptoms had endured for 8–48 years resulted in a complete resolution of symptoms in all four cases, which was maintained at follow-up.
Supports a basic tenet of the Adaptive Information Processing model that "Life events can generate at least as many PTSD symptoms as traumatic events." In a survey of 832 people, "For events from the past 30 years the PTSD scores were higher after life events than after traumatic event."
Reviews common errors and misperceptions of the procedures, research, and theory.
Specifically citing the hypothesis that EMDR induces processing effects similar to REM sleep (see also Stickgold, 2002, 2008), polysomnograms indicated a change in sleep patterns post treatment, and improvement on all measures including anxiety, depression, and quality of life after a mean of five sessions.
The authors note that the application of EMDR guided by the Adaptive Information Processing model appears to afford benefits to chronic pain patients not found in other treatments.
As predicted by the Adaptive Information Processing model the EMDR treatment of the molesters' own childhood victimization resulted in a decrease in deviant arousal as measured by the plethysmograph, a decrease in sexual thoughts, and increased victim empathy. Effects maintained at one year follow up.
10 consecutive cases of phantom limb pain were treated with EMDR resulting in the reduction or elimination of pain in all but two cases. Results were maintained at 2.8-year follow-up.
"Since September 2006, over 725 service-members from the global war on terrorism have survived combat-related traumatic amputations that often result in phantom limb pain (PLP) syndrome. . . . Four sessions of Eye Movement Desensitization and Reprocessing (EMDR) led to elimination of PLP, and a significant reduction in PTSD, depression, and phantom limb tingling sensations."
As predicted by the Adaptive Information Processing model the EMDR treatment of the event involving the limb loss, and the stored memories of the pain sensations, resulted a decrease or elimination of the phantom limb pain which maintained at 1-year follow-up.
Detailed presentation of case treated by EMDR that resulted in complete elimination of PTSD, depression and phantom limb pain with effects maintained at 18-month follow-up.
EMDR is an eight-phase psychotherapy with standardized procedures and protocols that are all believed to contribute to therapeutic effect. This text provides description and clinical transcripts and an elucidation of the guiding Adaptive Information Processing model.
EMDR is an integrative approach distinct from other forms of psychotherapy. Experts of the major psychotherapy orientations identify and highlight various procedural elements.
Overview of EMDR treatment based upon an Adaptive Information Processing case conceptualization. Early life experiences are viewed as the basis of pathology and used as targets for processing. The three-pronged protocol includes processing of the past events that have set the foundation for the pathology, the current triggers, and templates for appropriate future functioning to address skill and developmental deficits.
Overview of Adaptive Information Processing model, including how the principles are reflected in the procedures, phases and clinical applications of EMDR. Comprehensive worksheets for client assessment, case formulation, and treatment as well as scripts for various procedures.
Using an Adaptive Information Processing conceptualization a wide range of family problems and impasses can be addressed through the integration of EMDR and family therapy techniques. Family therapy models are also useful for identifying the targets in need of processing for those engaged in individual therapy.
This article provides a brief overview of some of the major precepts of the Adaptive Information Processing model, a comparison and contrast to extinction-based information processing models and treatment and a discussion of a variety of mechanisms of action.
The study evaluated the impact of EMDR treatment on bias mechanisms in depressed subjects in regard to negative emotional valence evaluation. "The results indicated that it generated important cognitive emotional changes in such mechanisms." Priming tests indicated changes in the negative valence evaluation of emotional information indicative of recovery with decreased reaction times in the neutral and positive stimuli processing."
Subsequent to EMDR treatment "all three patients made positive changes in attachment status as measured by the [Adult Attachment Inventory], and all three reported positive changes in emotions and relationships."
"Five consecutive cases of phantom limb pain were treated with EMDR. Four of the five clients completed the prescribed treatment and reported that pain was completely eliminated, or reduced to a negligible level. . . The standard EMDR treatment protocol was used to target the accident that caused the amputation, and other related events."
Mechanism of Action
EMDR contains many procedures and elements that contribute to treatment effects. While the methodology used in EMDR has been extensively validated (see above), questions still remain regarding mechanism of action. However, since EMDR achieves clinical effects without the need for homework, or the prolonged focus used in exposure therapies, attention has been paid to the possible neurobiological processes that might be evoked. Although the eye movements (and other dual attention stimulation) comprise one only one procedural element, this element has come under greatest scrutiny. Randomized controlled studies evaluating mechanism of action of the eye movement component follow this section.
Changes in heart rate, skin conductance and LF/HF-ratio, finger temperature, breathing frequency, carbon dioxide and oxygen levels were documented during the eye movement condition. It was concluded the "eye movements during EMDR activate cholinergic and inhibit sympathetic systems. The reactivity has similarities with the pattern during REM sleep."
EMDR treatment of autobiographic worries causing moderate distress resulted in an "increase in the smoothness of pursuit [which] presumably reflects an improvement in the use of visual attention needed to follow the target accurately. Perhaps EMDR reduces distress thereby activating a cholinergic effect known to improve ocular pursuit."
This study tested whether the content of participants' responses during EMDR is similar to that thought to be effective for traditional exposure treatments (reliving), or is more consistent with distancing which would be expected given Shapiro's proposal of dual focus of attention. Greatest improvement on a measure of PTSD symptoms occurred when the participant processed the trauma in a more detached manner, which indicates the underlying mechanisms of EMDR and exposure therapy are different.
Tested patients awaiting PTSD treatment and demonstrated that the eye movement condition had a significant effect on vividness of trauma memory and emotionality compared to counting and exposure only. In addition, "the counting task had no effect on vividness compared to exposure only, suggesting that the eye-movement task had a specific effect rather than serving as a general distractor" (p. 317)
One of a variety of articles positing an orienting response as a contributing element (see Shapiro, 2001 for comprehensive examination of theories and suggested research parameters). This theory has received controlled research support (Barrowcliff et al., 2003, 2004).
"Specifically, the EM manipulation used in the present study, reported previously to facilitate episodic memory, resulted in decreased interhemispheric EEG coherence in anterior prefrontal cortex. Because the gamma band includes the 40 Hz wave that may indicate the active binding of information during the consolidation of long-term memory storage (e.g., Cahn and Polich, 2006), it is particularly notable that the changes in coherence we found are in this band. With regard to PTSD symptoms, it may be that by changing interhemispheric coherence in frontal areas, the EMs used in EMDR foster consolidation of traumatic memories, thereby decreasing the memory intrusions found in this disorder."
Theoretical, clinical, and procedural differences referencing two decades of CBT and EMDR research.
This study was designed as primarily a process report to compare EMDR and exposure therapy. A different recovery pattern was observed with the EMDR group demonstrating a more rapid decline in self-reported distress.
During-session changes in autonomic tone were investigated in 10 patients suffering from single-trauma PTSD. Results indicate that information processing during EMDR is followed by during-session decrease in psychophysiological activity, reduced subjective disturbance and reduced stress reactivity to traumatic memory.
The psycho-physiological correlates of EMDR were investigated during treatment sessions of trauma patients. The initiation of the eye movements sets resulted in immediate changes that indicated a pronounced de-arousal.
Twenty-one patients with single-event PTSD (average IES: 49.5) received three consecutive sessions of EMDR with three different types of auditory and kinesthetic stimulation. All were clinically useful. However, alternating stimulation appeared to confer an additional benefit to the EMDR procedure.
Stickgold, R. (2008). Sleep-dependent memory processing and EMDR action. Journal of EMDR Practice and Research, 2, 289-299.
Comprehensive explanations of mechanisms and the potential links to the processes that occur in REM sleep. Controlled studies have evaluated these theories (see next section; Christman et al., 2003; Kuiken et al. 2001-2002).
The article explores the differences between memory reconsolidation and extinction. This new area of investigation is worthy of additional attention. Reconsolidation may prove to be the underlying mechanism of EMDR, as opposed to extinction caused by prolonged exposure therapies. "Memory reconsolidation after retrieval may be used to update or integrate new information into long-term memories . . . Brief exposure … seems to trigger a second wave of memory consolidation (reconsolidation), whereas prolonged exposure . . leads to the formation of a new memory that competes with the original memory (extinction)."
Study involving biofeedback equipment has supported the hypothesis that the parasympathetic system is activated by finding that eye movements appeared to cause a compelled relaxation response. More rigorous research with trauma populations is needed.
Randomized Studies of Hypotheses Regarding Eye Movements
A number of International Practice Guideline committees have reported that the clinical component analyses reviewed by Davidson & Parker (2001) are not well designed (International Society for Traumatic Stress Studies/ISTSS (2000); DoD/DVA, 2004). Davidson & Parker note that there is a trend toward significance for eye movements when the studies conducted with clinical populations are examined separately. Unfortunately even these studies are methodologically flawed. As noted in the ISTSS guidelines (Chemtob et al., 2000), since these clinical populations received insufficient treatment doses to obtain substantial main effects, they are inappropriate for component analyses. However, as noted in the DoD/DVA (2004) guidelines, numerous memory researchers have evaluated the eye movements used in EMDR. These studies have found a direct effect on emotional arousal, imagery vividness, attentional flexibility, and memory association. In addition, a new study has examined the hypothesis that the eye movements cause a "distancing effect" (Lee & Drummond, 2008) and is listed below as well.
Tested the working memory theory. Eye movements were superior to control conditions in reducing image vividness and emotionality.
Tested the reassurance reflex model. Eye movements were superior to control conditions in reducing image vividness and emotionality.
Tested the reassurance reflex model. Eye movements were superior to control conditions in reducing arousal provoked by auditory stimuli.
Tested cortical activation theories. Results provide indirect support for the orienting response/REM theories suggested by Stickgold (2002, 2008). Saccadic eye movements, but not tracking eye movements were superior to control conditions in episodic retrieval.
"This study examined whether eye movements reduce vividness and emotionality of visual distressing images about feared future events. . . Relative to the no-dual task condition, eye movements while thinking of future-oriented images resulted in decreased ratings of image vividness and emotional intensity."
Three studies were done that cumulatively support a working-memory account of the eye movement benefits in which the central executive is taxed when a person performs a distractor task while attempting to hold a memory in mind.
Tested the working memory theory. Eye movements were superior to control conditions in reducing within-session image vividness and emotionality. There was no difference one-week post.
Tested the orienting response theory related to REM-type mechanisms. Indicated that the eye movement condition was correlated with increased attentional flexibility. Eye movements were superior to control conditions.
"There was no significant effect of therapist's instruction on the outcome measures. There was a significant reduction in distress for eye movement at post-treatment and at follow-up. . . . The results were consistent with other evidence that the mechanism of change in EMDR is not the same as traditional exposure."
In two experiments participants focused on negative memories while engaging in three dual-attention eye movement tasks of increasing complexity. Results support a working memory explanation for the effects of eye movement dual-attention tasks on autobiographical memory.
Bilateral saccadic eye movements were compared to vertical and no eye movements. "It was found that bilateral eye movements increased true memory for the event, increased recollection, and decreased the magnitude of the misinformation effect." This study supports hypotheses regarding effects of interhemispheric activation and episodic memory.
Eye movements were superior to control conditions in reducing image vividness.
Tested their theory that eye movements change the somatic perceptions accompanying retrieval, leading to decreased affect, and therefore decreasing vividness. Eye movements were superior to control conditions in reducing image vividness. Unlike control conditions, eye movements also decreased emotionality.
Additional Psychophysiological and Neurobiological Evaluations of EMDR Treatment
All psychophysiological studies have indicated significant de-arousal. Neurobiological studies have indicated significant effects, including changes in cortical, and limbic activation patterns, and increase in hippocampal volume.
Combat Veteran Treatment
As noted in the American Psychiatric Association Practice Guidelines (2004, p.18), in EMDR "traumatic material need not be verbalized; instead, patients are directed to think about their traumatic experiences without having to discuss them." Given the reluctance of many combat veterans to divulge the details of their experience, this factor is relevant to willingness to initiate treatment, retention and therapeutic gains. It may be one of the factors responsible for the lower remission and higher dropout rate noted in this population when CBT techniques are used.
As described previously, Carlson et al. (1998) reported that after twelve treatment sessions, 77.7% of the combat veterans no longer met criteria for PTSD. There were no dropouts and effects were maintained at 3- and 9-month follow-up. In addition, the Silver et al., (1995) analysis of an inpatient veterans' PTSD program (n = 100) found EMDR to be superior to biofeedback and relaxation training on seven of eight measures. All other randomized studies of veterans have used insufficient treatment doses to assess PTSD outcomes (e.g., two sessions; see ISTSS, 2000; DVA/DoD, 2004). Sufficient treatment time must be used for multiply traumatized veterans (e.g., see below: Russell et al., 2007). However, in a process analysis, Rogers et al. (1999) compared one session of EMDR and exposure therapy with inpatient veterans, and a different recovery pattern was observed. The EMDR group demonstrated a more rapid decline in self-reported distress (e.g., SUD levels decreased with EMDR and increased with exposure).
As stated in the American Psychiatric Practice Guidelines (2004, p. 36), if viewed as an exposure therapy, "EMDR employs techniques that may give the patient more control over the exposure experience (since EMDR is less reliant on a verbal account) and provides techniques to regulate anxiety in the apprehensive circumstance of exposure treatment. Consequently, it may prove advantageous for patients who cannot tolerate prolonged exposure as well as for patients who have difficulty verbalizing their traumatic experiences. Comparisons of EMDR with other treatments in larger samples are needed to clarify such differences."
Such research is highly recommended. In addition, since EMDR utilizes no homework to achieve its effects it may be particularly suited for front line alleviation of symptoms (see Russell, 2006; Wesson & Gould, 2009). Further, the prevalent somatic and chronic pain problems experienced by combat veterans indicate the need for additional research based upon the reports of Russell (2008), Schneider et al., (2007, 2008) and Wilensky (2007), which demonstrate EMDR's capacity to successfully treat phantom limb pain (see also Ray & Zbik, 2001). The ability of EMDR to simultaneously address PTSD, depression, and pain can have distinct benefits for DVA/DoD treatment.
The following contain clinically relevant information for the treatment of veterans, including therapy parameters.
IMPORTANTE: Con este entrenamiento usted cumplirá con la Norma Oficial Mexicana 046-SSA2-2005, referente a la atención para los usuarios de los Servicios de Salud. Esta Norma es de observancia obligatoria para las instituciones del Sistema Nacional de Salud, así como para los y las prestadoras de servicios de salud de los sectores público, social y privado que componen el Sistema Nacional de Salud. Su incumplimiento dará origen a sanción penal, civil o administrativa que corresponda, conforme a las disposiciones legales aplicables.
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