A Multicenter Phase II Rater-Blinded Randomized Controlled Trial to Compare the Effectiveness of Eye Movement Desensitization Reprocessing Therapy vs. Treatment as Usual in Patients With Substance Use Disorder and History of Psychological Trauma

Background:

Substance use disorders (SUD) represent an important social and public health problem due to their negative consequences in terms of delinquency, family disintegration, academic and occupational disengagement, mental illness, transmission of infectious diseases, intoxication and mortality rates. As with other mental disorders, the evolution of this disorder depends on many biological and sociodemographic variables, such as the age of onset of consumption, access to drugs, one's living environment, race, and the presence of stressors. Of all these variables, adverse events are being increasingly investigated, due to the strong negative impact they have on the onset, course and prognosis of psychiatric disorders, especially when psychological trauma is present. Traumatic events, especially in childhood or adolescence, are considered to be a robust risk factor for developing post-traumatic stress disorder (PTSD), with or without further comorbid severe mental disorders such as depression, bipolar disorder, psychosis or SUD. A recent meta-analysis published in the Lancet found multiple adverse childhood events to be a significant risk factor for problematic alcohol and substance use, highlighting the impact of adverse childhood events even when not associated with a diagnosis of PTSD. Although there is currently no available data about the prevalence of traumatic events in SUD patients population, it is estimated that is likely high presumed to be high. The results of different studies estimate that the prevalence of PTSD in inpatients with SUD to ranges from 25% -51%, which is two to four times higher than the prevalence range found in the general population (1.3% -12.3%). In addition, evidence suggests that PTSD and traumatic events are correlated with addiction severity, with a worse disease prognosis, with a greater number of hospitalizations, with a poorer response to treatment, with shorter periods of abstinence and with greater craving. Thus, an integral model with an individualized treatment plan is indicated in SUD, including psychological trauma as a specific objective to address.

A possible candidate for this is Eye Movement Desensitization and Reprocessing (EMDR) therapy, which is considered to be a first line treatment for PTSD, being recommended by different international bodies, such as the American Psychiatric Association (APA) and World Health Organization (WHO). EMDR is a psychotherapeutic approach designed to alleviate the distress associated with traumatic memories, facilitating the access to and processing of traumatic memories and other adverse life experiences and bringing these to an adaptive resolution using standardized protocols and elements of cognitive behavioral, interpersonal, and body-centered therapies in conjunction with bilateral stimulation (e.g. horizontal eye movements from side to side). In recent years, the use of EMDR has increased exponentially in clinical practice due its effectiveness and safety and that has resulted in investigations in additional populations beyond PTSD, such as in those with depression, anxiety, chronic pain, bipolar disorder, or psychosis. Of note, three small randomized controlled trials (RCT) of EMDR versus Treatment As Usual (TAU) have also been performed in patients with SUD. The results suggest that EMDR, compared to the control group, significantly improved craving, depression, anxiety, self-esteem and dissociative symptoms, but samples were small. A large scale RCT is currently underway, which aims to determine the efficacy of EMDR in reducing PTSD symptoms in an inpatient sample with comorbid PTSD or subthreshold PTSD and SUD. In view of the above, we consider that a further large RCT of EMDR in the treatment of psychological trauma in outpatients with SUD, including psychological trauma related to adverse events not covered by DSM-V diagnostic criteria, is crucial and clinically necessary due to the negative impact it has on the course and prognosis of these illnesses, and in order to confirm or reject prior first positive evidence. Our study is also important in including patients with dual pathology and measuring impact on psychopathological symptoms, which will help facilitate the application of EMDR in a real world setting if it is shown to be efficacious.

Design:

This is a single-blind RCT with two parallel branches, EMDR and TAU, in patients diagnosed with SUD who have suffered from comorbid psychological trauma. The patients will be matched by center, age, sex and diagnosis. One group will consist of TAU + 20 individual EMDR sessions, 60 minutes each, during 6 months, the other group will receive TAU only. Patients will be evaluated at baseline, at 3 months, post-treatment at 6 months and at 12 months as follow-up.