Here is the design of a clinical trial:

Official Title: Treatment of Major Depressive Disorder With Bilateral Theta Burst Stimulation

Included conditions:
- Major Depressive Disorder

Study Armgroups:
- {'label': 'combined iTBS/cTBS', 'type': 'ACTIVE_COMPARATOR', 'description': 'Combined theta burst stimulation (TBS) of the left (intermittent TBS, iTBS) and right (continuous TBS, cTBS) dorsolateral prefrontal cortex (dlPFC; F3 and F4 according to EEG10/20 system). Each stimulation session will comprise 2 trains of 600 stimuli each applied in bursts of three pulses at 50 Hz given every 200 ms. iTBS will be applied 20 times for 2 s every 10 s. In the same session, stimulation with cTBS will be applied continuously for 40 s. Intensity of iTBS/cTBS will be standardized at 80 % of the resting motor threshold (rMT).\n\nAdditionally, patients receive an electrical co-stimulation of the forehead. One electrode is fixed to FZ and the 2nd one is either fixed to the left forehead (iTBS) or the right forehead (cTBS), rectangular aligned to the upper edge of the FZ-electrode with a distance of 0.5 cm. Intensity of the co-stimulation is applied with 50% of TBS-intensity.', 'interventionNames': ['Device: Transcranial Magnetic Stimulation']}
- {'label': 'sham stimulation', 'type': 'SHAM_COMPARATOR', 'description': 'Setup is identical to combined active iTBS/cTBS but TBS is not actively delivered', 'interventionNames': ['Device: Sham Transcranial Magnetic Stimulation']}

Interventions:
- {'type': 'DEVICE', 'name': 'Transcranial Magnetic Stimulation', 'description': 'MagVenture Coil Cool B70 A/P', 'armGroupLabels': ['combined iTBS/cTBS']}
- {'type': 'DEVICE', 'name': 'Sham Transcranial Magnetic Stimulation', 'description': 'MagVenture Coil Cool B70 A/P without TMS being actively delivered', 'armGroupLabels': ['sham stimulation']}

Primary Outcomes:
- {'measure': 'Response rate of Montgomery-Asberg Depression Rating Scale (MADRS)', 'description': 'MADRS reduction of at least 50% of baseline value after end of treatment period between active combined iTBS / cTBS and the sham condition.\n\n(rater questionnaire; MADRS raw score ranges between 0 and 60; the higher the score, the more severe depression)', 'timeFrame': '6 weeks'}

Please estimate the sample size based on the assumption: 
Chi-square test, alpha = 0.05 two-sided, beta = 0.2, and a 10% dropout rate.
Sample size calculation
        In an own pilot study (nâ=â32) we found 9/16 (56%) responders (MADRSââ¤â50% of baseline) in the verum group and 4/16 (25%) responders in the sham group [28]. In a second pilot study (nâ=â60) of another group [29] response rates (HDRS-17ââ¤â50% of baseline) were 66.7% vs. 13.3% after 2Â weeks treatment and 4/15 (27%) vs. 1/15 (7%) after week 14. In the third pilot study (nâ=â56) [30] response rates (HDRS-17ââ¤â50% of baseline) were 55% (bilateral TBS) and 30% (sham TBS), 7Â weeks after initiation of a 3Â weeks treatment. In a recent large (total nâ=â385) clinical trial [18] comparing iTBS (nâ=â193) with 10Â Hz rTMS (nâ=â192) the outcome criterion of HDRS-17ââ¤â50% of baseline was achieved by 49% of patients treated with iTBS. Based on these studies, we conservatively assume a response rate of 49% vs. 30% (combined bilateral TBS vs. sham TBS) using the criterion MADRS reduction of at least 50% compared to baseline. This leads to a sample size of 103 subjects per group (Chi-square test, alphaâ=â0.05 two-sided, betaâ=â0.2), totally 206 evaluable subjects. As we will recruit in seven centers we increase the sample size by nâ=â6 to compensate for degrees of freedom in a stratified analysis which leads to 212 patients. The analysis will be done on the full set of patients except for those refusing consent during the study or not receiving at least one treatment. We expect a low dropout rate and therefore, we increase the sample size by 24 subjects to adjust for 10% dropouts, which leads to a total n of 236 patients.