Single Session of tACS in a Depressive Episode
Condition: Depression; Major Depressive Disorder; Premenstrual Dysphoric Disorder; Depressive Episode
MeSH terms: Premenstrual Dysphoric Disorder; Depression; Depressive Disorder; Depressive Disorder, Major
Study type: Interventional

Summary: 
      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).
    

Detailed description: 
      Participants will report for a study visit and will review and sign a consent form.

      Participants will complete several clinical assessments and also take a urine drug test and
      urine pregnancy test (if applicable). Eligibility will be re-assessed by the investigators
      before the participant moves on to the next phase.

      If the participant still qualifies, the participant will first be fitted with two 5x5cm
      electrodes placed over F3/F4 (10-20 measurement system) and one 5x7cm electrode placed over
      Cz. In addition, the participant will have a 128-channel EEG net placed on their head.
      Participants will provide a saliva sample to assess for brain-derived neurotrophic factor
      (BDNF), which may affect how the participant's brain responds to stimulation. Once the
      participant is fitted with this equipment, the participant will complete two interactive EEG
      tasks, then 2-minute resting state EEG with the participant's eyes closed, then a 5-minute
      resting state EEG with the participant's eyes open.

      Following these recordings, participants will respond to additional questionnaires.
      Immediately following this, the participant will receive 40 minutes of stimulation (tACS or
      sham tACS). During this stimulation, participants will sit comfortably upright and awake.

      After stimulation has completed, participants will respond to additional questionnaires. Once
      completed, participants will then complete an additional 5-minute resting state EEG with the
      participant's eyes open, as well as complete one of the additional interactive EEG tasks.

      Finally, participants will respond to a blinding questionnaire to assess if the participant
      thought that the participant received stimulation. Once complete, the participant will leave.
      This session is estimated to last about 4 hours.
    

Intervention name(s): XCSITE100 Stimulator Sham; XCSITE100 Stimulator tACS
Intervention type(s): Device; Device
Intervention description(s): The participant will receive up to one minute of tACS stimulation until the stimulation fades. Sham stimulation mimics the skin sensations a participant would experience during a tACS session.; Transcranial alternating current stimulation (tACS) is a method of noninvasive brain stimulation in which weak electrical current are applied to the scalp in a sine wave pattern to induce cortical oscillations at the frequency at which they are applied.
Other intervention name(s): Sham tACS; tACS
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: This study recruits both participants currently experiencing a depressive episode (regardless of diagnosis) and those with no history of neurological or psychiatric illness. Randomization will occur in a 1:1 ratio for both of these groups, with half of each group receiving transcranial alternating current stimulation (tACS) at 10 Hz and the other half receiving placebo (or sham) stimulation.
Masking: Double (Participant, Investigator)
Primary purpose: Basic Science
Keywords: tACS; transcranial alternating current stimulation; stimulation; heart rate variability; electroencephalogram; EEG