Here is the design of a clinical trial:

Official Title: Augmentation of EMDR With Transcranial Direct Current Stimulation in the Treatment of Fibromyalgia: a Randomized Controlled Trial

Included conditions:
- Fibromyalgia
- Psychological Trauma
- Depressive Symptoms
- Anxiety

Study Armgroups:
- {'label': 'EMDR plus MtCS', 'type': 'ACTIVE_COMPARATOR', 'description': 'MtCS stimulation will consist of 1mA MtDCS for 20 minutes applied immediately before EMDR sessions.', 'interventionNames': ['Behavioral: Eye Movement Desensitization and Reprocessing therapy', 'Other: Multifocal transcranial Current Stimulation']}
- {'label': 'EMDR plus sham-MtCS', 'type': 'PLACEBO_COMPARATOR', 'description': 'Sham stimulation will consist of inactive MtDCS for 20 minutes applied immediately before EMDR sessions', 'interventionNames': ['Behavioral: Eye Movement Desensitization and Reprocessing therapy']}
- {'label': 'Treatment as Usual', 'type': 'NO_INTERVENTION', 'description': 'Patients in this condition will not receive EMDR nor MtCS sessions, and will continue to attend their regular visits with rheumatology and psychiatry. The patients from the TAU group will have the choice to attend 10 sessions of EMDR group therapy when the research project finishes.'}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'Eye Movement Desensitization and Reprocessing therapy', 'description': 'EMDR is a psychotherapeutic approach using a standardized 8-phase protocol to alleviate the distress associated with traumatic memories, facilitating the access to and processing of traumatic memories. Patients will receive 20 individual EMDR sessions of 60 minutes each using the standard protocol, as well as a specific pain protocol and the fibromyalgia protocol. EMDR is an integrative psychotherapy that uses standardized protocols and elements of cognitive-behavioral, interpersonal, and body-centered therapies, as well as dual stimulation (e.g., side-to-side eye movements).\n\nThe current standard protocol includes eight phases:\n\nPatient history. Patient preparation. Patient assessment. Memory desensitization. Installing the positive cognition. Body scan. Closure. Reevaluation.', 'armGroupLabels': ['EMDR plus MtCS', 'EMDR plus sham-MtCS'], 'otherNames': ['EMDR']}
- {'type': 'OTHER', 'name': 'Multifocal transcranial Current Stimulation', 'description': 'MtCS represents a promising intervention option, given its capacity to modulate cerebral excitability in a simple, safe manner. F3 anodal; AF3, FC1, FC3, FC5, F5, return montage will be used with the anode over the left DLPFC. Half of the patients will receive active stimulation and the other half sham stimulation. Active stimulation will consist of 1mA MtDCS for 20 minutes applied immediately before EMDR sessions. The same protocol and montage will be used for sham stimulation.', 'armGroupLabels': ['EMDR plus MtCS'], 'otherNames': ['MtCS']}

Primary Outcomes:
- {'measure': 'Change in pain assessed with the Visual Analogic Scale Questionnaire.', 'description': 'Severity and changes in pain intensity will be assessed with the Visual Analogic Scale (rated in a continuum from 0 to 10).', 'timeFrame': 'Change from baseline to visits at 6 and 12 months'}
- {'measure': 'Change in pain assessed with the Pain Dissability Index.', 'description': 'Severity and changes in pain intensity will be assessed with the Pain Disability Index (7 items rated from 0 to 10, making a total score from 0 to 70).', 'timeFrame': 'Change from baseline to visits at 6 and 12 months'}
- {'measure': 'Change in pain assessed with the Fibromyalgia Impact Questionnaire.', 'description': 'Severity and changes in pain intensity will be assessed with the Fibromyalgia Impact Questionnaire (the first items is rated from 0 to 4, the second from 0 to 7 and the third from 0 to 5; whereas the other 7 items are rated from 0 to 10, with a cut-off score of 50).', 'timeFrame': 'Change from baseline to visits at 6 and 12 months'}
- {'measure': 'Change in depressive symptoms assessed by with the Hospital Anxiety and Depression Scale', 'description': 'Severity and changes in depressive symptoms will be evaluated with the Hospital Anxiety and Depression Scale. Items are rated on a 4-point Likert scale from 0 and 3, yielding a total score ranging from 0 to 21 and a cut-off score of 8 indicating probable clinical symptoms.', 'timeFrame': 'Change from baseline to visits at 6 and 12 months'}
- {'measure': 'Change in anxious symptoms evaluated with the Hospital Anxiety and Depression Scale.', 'description': 'Severity and changes in anxious symptoms will be evaluated with the Hospital Anxiety and Depression Scale. Items are rated on a 4-point Likert scale from 0 and 3, yielding a total score ranging from 0 to 21 and a cut-off score of 8 indicating probable clinical symptoms.', 'timeFrame': 'Change from baseline to visits at 6 and 12 months'}
- {'measure': 'Change in trauma associated symptoms assessed with the Impact of Events Scale-Revised.', 'description': "Psychological trauma will be evaluated using the Impact of Events Scale-Revised. This scale consists in 22-item to determine frequency and impact of posttraumatic symptoms experienced, with subscales of intrusion, avoidance and hyperarousal, each scored on a 5-point Likert scale, yielding a score for each subscale and a total score. This scale has a scoring range of 0 to 88. On this test, scores that exceed 24 can be quite meaningful. High scores have the following associations: 24 or more PTSD is a clinical concern. Those with scores this high who do not have full PTSD will have partial PTSD or at least some of the symptoms; 33 and above represents the best cutoff for a probable diagnosis of PTSD; 37 or more this is high enough to suppress your immune system's functioning (even 10 years after an impact event).", 'timeFrame': 'Change from baseline to visits at 6 and 12 months'}

Please estimate the sample size based on the assumption: 
significance level of 0.05, statistical power of 80%, 15% dropout rate
Sample size calculation
        The main tests of the study will consist of assessing whether patients assigned to EMDR show different levels in the pain intensity variable using a standard formula for two-tailed t-tests. The total sample size required to detect large to very large effect size differences (Cohenâs dââ¥â1) between three groups with a significance level of 0.05 and statistical power of 80% is 28. Assuming 15% dropouts, we will aim to randomize 96 patients, meaning 32 per group.