Investigating Transcranial Ultrasound as a Potential Intervention for Depression

Participants will first complete the online screening and those who qualify to complete the study will be contacted via telephone (see above for telephone recruitment and consent procedure). After providing informed consent, on the first day, participants will be randomly assigned to either a TUS treatment or a TUS sham condition (placebo), and the study will be double blind. Participants in the TUS treatment condition (with sham or treatment unknown to both participant and experimenter) will have TUS stimulation at the right fronto-temporal area five times within seven days or ten times within fourteen days. Participants will sign up for the first five sessions first but will be reminded participants may withdraw from the study at any time. Should participants choose to continue with the second week of treatment, participants will be scheduled for another five sessions. In other words, participants will have the option of completing 10 days of the procedure. The procedure does not differ between week 1 and week 2. However, participants will be compensated less for week 2. Participants will have the option to continue into week 2, as participants may find that the treatment is benefiting them. The first, fifth, and tenth days of the study will take approximately 2 hours and the second, third, fourth, sixth, seventh, eighth, and ninth will take only one hour. In the sham condition, the ultrasound probe will be placed at the right fronto-temporal area five times over the course of seven days or ten times over the course of fourteen days without the stimulation. Prior research has shown that stimulation at this area induces positive mood change and is implicated in positive mood. On the first, middle, and last day of the procedure (day 1, 5, 10), EEG data will be collected. On the second, third, and fourth day as well as sixth through ninth days of the procedure EEG data will not be collected and only TUS stimulation will occur. Collecting EEG data at these points will allow for comparison of resting electrical brain profiles from the beginning of the study to the end of the study. Additionally, the investigators will assess state mood and rumination before and after TUS, as well as depressive and anxiety symptoms at the end of each day. The state mood and rumination will allow us to examine the mood effects of TUS, whereas the depressive and anxiety symptoms questionnaires will allow us to examine any changes in these important profiles over the course of the study.