This study is a research trial of an outpatient, non-medication, non-invasive investigational treatment called Transcranial Magnetic Stimulation (TMS). TMS is a noninvasive tool for the study of the human brain that has been approved by the FDA for use in depression, but it is also being investigated as a potential therapeutic agent for other symptoms, such as those seen in Depersonalization Disorder (DPD).

TMS applies a magnetic field to the brain for a brief period of time. TMS is a procedure that involves 30 minute-long daily sessions every weekday for a series of weeks. The investigators are testing whether TMS can treat Depersonalization Disorder (DPD).

In this trial, 32 adult outpatients with DPD, that have been only partially responsive to conventional therapies, will be treated with active or sham low frequency (1 Hz) rTMS applied to the right temporo-parietal junction (TPJ) daily for up to six weeks.

DPD symptoms will be monitored through weekly self-report questionnaires as well clinical ratings with a doctor.