Abnormal brain oscillations persist after recovery from bipolar depression

Publication date: March 2017 Source:European Psychiatry, Volume 41 Author(s): P. Canali, S. Casarotto, M. Rosanova, G. Sferrazza-Papa, A.G. Casali, O. Gosseries, M. Massimini, E. Smeraldi, C. Colombo, F. Benedetti When directly perturbed in healthy subjects, premotor cortical areas generate electrical oscillations in the beta range (20–40Hz). In schizophrenia, major depressive disorder and bipolar disorder (BD), these oscillations are markedly reduced, in terms of amplitude and frequency. However, it still remains unclear whether these abnormalities can be modulated over time, or if they can be still observed after treatment. Here, we employed transcranial magnetic stimulation (TMS) combined with EEG to assess the frontal oscillatory activity in eighteen BD patients before/after antidepressant treatments (sleep deprivation and light therapy), relative to nine healthy controls. In order to detect dominant frequencies, event related spectral perturbations (ERSP) were computed for each TMS/EEG session in all participants, using wavelet decomposition. The natural frequency at which the cortical circuit oscillates was calculated as the frequency value with the largest power across 300ms post-stimulus time interval. Severity of depression markedly decreased after treatment with 12 patients achieving response and nine patients achieving remission. TMS/EEG resulted in a significant activation of the beta/gamma band response (21–50Hz) in healthy controls. In patients,...
Source: European Psychiatry - Category: Psychiatry Source Type: research