Bipolar Transcranial Alternating Current Stimulation (tACS)

Not Applicable

Completed

Conditions: Bipolar Disorder

Interventions: Device: Sham stimulation treatment
Device: tACS brain stimulation treatment

Registration Number: NCT05480124

Lead Sponsor: University of Michigan

Brief Summary: The purpose of this clinical trial is to measure the safety and effectiveness of a non-invasive brain stimulation device called Transcranial Alternating Current Stimulation (tACS) in participants with bipolar disorder (BD).

Participants will be asked to come in for 3 sessions. If participants qualify at the screening visit (session 1) then enrolled participants will complete sessions 2 and 3 as well as have a 30-day follow-up phone call.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 18

Inclusion Criteria

Confirmed diagnosis of BD based on Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV) criteria being met from previous enrollment in the Prechter Bipolar Longitudinal Study
This study will select BD patients that scored above published norms (upper 50th percentile) on the NEO-PI impulsivity facet to ensure that the recruited patients exhibit the network dysfunction targeted by the tACS paradigm and therefore have the potential to benefit from this neuromodulation technique.
Patients must be on a stable dose of medication for two weeks prior to Sessions 2 and 3.

Exclusion Criteria

Significant neurological abnormalities, such as seizure disorder, mass lesions, etc.
Known Mendelian disorder
Active problematic substance use in the past 30 days (as determined by the Substance Use Disorder module of SCID)
Evidence of suicidal intentions or behaviors in the past month, as judged by affirmative responses to question number 4 or number 5 on the Columbia Suicide Severity Rating Scale (CSSRS) or report of suicidal behaviors in the last 6 months
Pregnant or trying to become pregnant, or currently lactating.

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Sham stimulation treatment	Sham stimulation treatment	Sham stimulation during a computerized task and electroencephalogram (EEG) recording.
tACS brain stimulation treatment	tACS brain stimulation treatment	tACS brain stimulation during a computerized task and EEG recording. Participants will receive tACS using individualized peak Phase-amplitude coupling (PAC) frequency pairs determined in Session 1.

Primary Outcome Measures

Name	Time	Method
Severity of Side Effects Reported at End of Stimulation Session as Reported by the Participant on the Stimulation Side Effects Questionnaire.	Up to 3 weeks	The score was calculated by summing the severity score of items that were rated by the participant as related to stimulation on the Stimulation Side Effects Questionnaire. There was a total of 14 symptoms listed on the questionnaire. Participants rated each item rated on a scale of 0-4, with 0 meaning no relation and 4 meaning definitely related. The total possible range of the questionnaire was 0-56.
Accuracy Signal Detection Theory Metric Response Bias Derived From the Behavioral Responses to Go and NoGo Trials on the Cognitive Control Task.	Up to 3 weeks	The Go/NoGo task was a cognitive task, where participants were shown "go" stimuli (i.e., go trials) and "no-go" stimuli and responded by pressing a button when seeing "go" stimuli and not responding when seeing the "no-go" stimuli. Response bias was measured using beta, such that more negative beta values indicated a stronger tendency to respond to all stimuli, regardless of "go" or "no-go" status. Response bias is indexed by taking the average between the Z-score of the False Alarm Rate and the Z-scores of the Hit Rate. A higher response bias indicates that the participant is more likely to respond "signal absent" (favors avoiding false alarms but increases misses). A response bias of 0 means the individual equally weighs the costs of misses and false alarms. A more negative response bias indicated that the participant is more likely to respond "signal present" (favors hits but increases false alarms).
Reaction Time (in Milliseconds) of Go Trials on the Cognitive Control Task	Up to 3 weeks	Participants' reaction time to responding to the "Go" signal during the Go/NoGo task was measured.
Participants Who Withdrew During or After the Stimulation Session	Up to 3 weeks	Results reflect the number of participants who withdrew from the trial during or after a stimulation session with either the tACS or the sham stimulation treatment.
Accuracy Signal Detection Theory Metric Sensitivity (d') Derived From the Behavioral Responses to Go and NoGo Trials on the Cognitive Control Task.	Up to 3 weeks	The Go/NoGo task was a cognitive task, where participants were shown "go" stimuli (i.e., go trials) and "no-go" stimuli and responded by pressing a button when seeing "go" stimuli and not responding when seeing the "no-go" stimuli. Accuracy was measured by calculating D' (D prime), which provided a measure of perceptual sensitivity to the differing stimuli. Larger values of D' indicated greater discernability (i.e., accuracy) between the Go and NoGo trials. D-prime, also called the sensitivity index represents how well someone can detect a signal amidst background noise. At its core, D-prime is the standardized difference between the means of the Signal Present and Signal Absent distributions, which can be calculated by taking the difference between the Z-score of the False Alarm Rate and the Z-scores of the Hit Rate. A D-prime of 0 means no sensitivity. Negative D-prime values are rare and may indicate errors or reversed interpretations of hits and false alarms.
Theta-gamma Phase Amplitude Coupling (PAC) (Kullback-Leibler Modulation Index) During the Rest EEG Blocks Interleaved Between Stimulation Blocks.	Up to 3 weeks	Theta-gamma phase-amplitude coupling (PAC) is a neural phenomenon observed in the brain, where the phase of slower theta oscillations modulates the amplitude of faster gamma oscillations. This type of coupling is thought to play a critical role in various cognitive control. For the trial, higher PAC values indicated higher levels of coupling or connection between the two frequencies (i.e., increased cognitive control).