Transcranial Direct Current Stimulation (tDCS) as an Adjunctive Treatment for Treatment Resistant Depression (TRD)

A Feasibility Study of Transcranial Direct Current Stimulation (tDCS) as an Adjunctive Treatment for Treatment Resistant Depression (TRD) in Hospitalized Patients

The researchers are trying to test the feasibility and acceptability of using transcranial Direct Current Stimulation (tDCS) in hospitalized adult patients with Treatment Resistant Depression (TRD), assess for any preliminary effect on depressive and cognitive symptoms, and explore the utility of biomarkers to assess response to tDCS.

In this feasibility study the researchers propose to conduct a 5-day tDCS treatment protocol in hospitalized adult patients with TRD, with each treatment session lasting for 30 minutes, delivered twice daily, for a total of 10 stimulations over 5 days. Before and after the 5-day tDCS treatment protocol, assessments will include Montgomery-Asberg Depression Rating Scale (MADRS) to measure depressive symptoms, Snaith-Hamilton Pleasure Scale (SHAPS) to measure anhedonia, Stroop Test to measure memory and executive function, Revised Hopkins Verbal Learning Test (HVLT-R) to test verbal learning and memory, and Digital Symbol Coding Test (DSCT) to measure working memory. Electroencephalography (EEG) for objective electrophysiologic data will also be collected before and after tDCS. A wireless EEG unit (CGX, Cognionic, Inc.) will be used to collect EEG and peak alpha frequency (PAF) as potential target engagement marker for tDCS. The PAF measures the highest magnitude within the alpha range of brain oscillations, thought to reflect cognitive performance. Other potential predictors of treatment response measures collected at baseline include Adverse Childhood Experiences (ACE), premorbid intelligence quotient (pIQ), Wide Range Achievement Reading Test (WRART), and Socioeconomic Status (SES).

Inclusion Criteria

• 18 years and older
• Clinical diagnosis of treatment-resistant depression (defined as depression that does not remit following two or more treatment attempts of an adequate dose and duration of a minimum duration of 4 weeks)
• Hospitalized in psychiatric units
• Voluntary admission status
• Moderate or severe depression, defined by PHQ-9 ≥ 15
• Ability to provide informed consent
• Ability to adhere to protocol

Exclusion Criteria

• Bipolar disorder
• Active primary psychotic or substance use disorders (except nicotine dependence) within the past year
• Any active neurological condition (including seizure disorder, traumatic brain injury, stroke)
• Contraindications to tDCS (including pacemaker, metallic implants in the head or neck [except orthodontic hardware], skin disease causing irritation)
• Current pregnancy or positive urine pregnancy test (clinical)
• Any neuromodulation therapy (including ECT, rTMS, DBS, VNS, TES) within the last 3 months