Single Session of tACS in a Depressive Episode

Purpose: Investigating the effects of non-invasive transcranial alternating current stimulation (tACS) on healthy participants and participants with mood disorders. Participants: 40 males and females, ages 18-65, with depressed mood; 40 healthy males and females, ages 18-65, free of neurological or psychiatric conditions. Procedures: This is a single visit study with two stimulation conditions (tACS and sham tACS). The session will begin with clinical assessments (including confirmation of diagnosis), followed by an interactive EEG task, then a 7 minute resting state EEG (2 minutes eyes closed, 5 minutes eyes open), followed by the stimulation session (40 minutes of tACS or sham tACS), followed by an additional 5 minute resting state EEG. The stimulation will involved 40 minutes of transcranial alternating current stimulation, 2 mA in amplitude and at individualized alpha frequency (determined by the 2 minutes eyes closed EEG recording; between 8 and 12Hz).