2.2 Study design and participants
depression, bipolar depression, psychiatric, depressive
This study uses data from a randomized parallel double-blind sham-controlled trial that was pre-registered at the U.S. National Library of Medicine (i.e., ClinicalTrials.gov), with the registration ID of NCT02905604. In the current work, the sample size was based on a previous study with a similar design, in which the response rate was indicated as 17% for sham treatment and 52% for active treatment in the depression cohort [The 42 age-eligible (18–59 years old) patients (mean age: 29 ± 9.4, 21 women) who were included in the current study were recruited from the psychiatric outpatient clinic at the Uppsala University Hospital, Sweden. This data collection started in September 2016 and ended in January 2020. The experiment came to an end after collecting the required amount of data from the intended number of patients, as determined by the sample size assessment. All patients were diagnosed with either uni- or bipolar depression (n = 3) and fulfilled the criteria of an ongoing depressive episode determined through the Mini International Neuropsychiatric Interview [