John P. O’reardon, MD

Identification of atypical features is important in the treatment of depression for both treatment selection and prognosis, especially when initial measures prove ineffective. The concept of atypical depression has evolved over many years, and now it appears timely for a further revision.

Transcranial magnetic stimulation (TMS) is noninvasive focused brain stimulation that uses pulsed magnetic fields. The underlying mechanism depends on the principle of electromagnetic induction, the process (discovered by Faraday in 1839) by which electrical energy is converted into a magnetic field and vice versa.1