Testing a neurobiological model of depersonalization with Transcraneal Magnetic Stimulation.
Why are we doing this research?
Depersonalization disorder (DPD) is a poorly understood condition characterised by a chronic, distressing and often incapacitating alteration in the perception or experience of the self. The aim of this project is to refine and test our neuropsychological model of DPD which will open up a translational pathway to neurobiologically informed treatments. Our work has established that DPD is characterized by attenuated skin conductance responses (SCR), which are functionally related to reduced activation in brain areas underpinning affective responses, and by increased activation in prefrontal areas involved in emotion regulation.
What are we doing?
We are testing the hypothesis that DPD stems from dysfunctionally increased fronto-insula/limbic inhibitory regulation. We using MRI-guided repetitive transcranial magnetic stimulation (rTMS) in two, contrasting, participant-blind interventions (low and high frequency stimulation) in DPD patients and healthy volunteers. We will measure responses to emotional pictures, both objective – autonomic SCRs, and subjective - self-report arousal ratings, and these will be our co-primary outcomes. We predict that:
1. in DPD patients, low frequency (1 Hz) rTMS induced suppression of prefrontal activity will result in: increased SCRs to arousing pictures (i.e. emotional responses will be released from dysfunctional frontal inhibition) and increased subjective ratings of emotional arousal and reduced symptoms;
2. in healthy volunteers, high frequency (10 Hz) rTMS stimulation will activate the same prefrontal regions which will result in blunted subjective and autonomic responses resembling those of depersonalized patients.
Who is involved?
The study is being carried out by the following researchers of the depersonalization disorder Unit: Mauricio Sierra-Siegert, Emma-Louise Hanif, Anthony S. David
Who funds the study?
Psychiatry Research Trust
Mauricio Sierra-Siegert or Emma-Louise Hanif