Transcranial Direct Current Stimulation (tDCS) as a Treatment for Cognitive Deficits in Schizophrenic
Condition: Schizophrenia
MeSH terms: Schizophrenia; Cognition Disorders; Cognitive Dysfunction
Study type: Interventional

Summary: 
      This trial attempts to evaluate the effects of intensive transcranial direct-current
      stimulation (tDCS) on improving cognition in schizophrenia patients and changes in resting
      state brain network connectivity, especially increasing connectivity in the tasks related
      network, and increasing activation the DLPFC in a working memory task. Half of the
      participants will be randomized to tDCS group, while the other half will be randomized to
      receive sham tDCS.
    

Detailed description: 
      Schizophrenia patients (SZ) show profound and persistent cognitive deficits in attention,
      executive processing, and verbal and visuospatial memory, which persist even after psychotic
      symptoms are ameliorated. Cognitive deficits may be more important in preventing functional,
      occupational, and social recovery in SZ than other symptom domains and are not effectively
      treated by current pharmacological approaches. Transcranial direct-current stimulation (tDCS)
      is less expensive than other modalities (e.g. repetitive transcranial magnetic stimulation;
      rTMS), easily available, and has a good safety profile in healthy controls (HC) and SZ.
      However, these prior studies did not make use of a validated measure such as the MATRICS
      consensus battery (MCCB), which is now established as the standard for assessing cognitive
      improvement in SZ. Despite these promising preliminary results, this effect of tDCS in SZ
      needs to be confirmed and the underlying biological mechanism elucidated. Therefore, the
      investigators employed MCCB to evaluate the effects on improving cognition and functional MRI
      to explore the underlying mechanism.

      Half of the participants will be randomized to tDCS group, while the other half will be
      randomized to receive sham tDCS. Active vs. sham treatment will be randomly using computer
      generated lists. Subjects and researcher-administrators of tDCS and testers or evaluators
      will be blind to treatment.The main cognitive outcome measure, the MCCB, will be administered
      at baseline and 1 day after the last tDCS session.Participants will be scanned once prior to
      tDCS sessions, and within one day after the 10th tDCS sessions using our Siemens 3T Verio MRI
      scanner.
    

Intervention name(s): tDCS; Sham tDCS
Intervention type(s): Device; Device
Intervention description(s): Electrodes for tDCS will have the anode placed over the left DLPFC (F3) and the cathode over the contralateral (right) supraorbital ridge. The exact location of electrodes will be determined by the 10/20 EEG method with EEG cap. Subjects will have tDCS sessions on consecutive days (weekends and holidays excluded). The tDCS group will have 10 active or sham tDCS sessions. The active group will be stimulated with a 2 mA current for 20 minutes.; Electrodes for tDCS will have the anode placed over the left DLPFC (F3) and the cathode over the contralateral (right) supraorbital ridge. The exact location of electrodes will be determined by the 10/20 EEG method with EEG cap. Subjects will have tDCS sessions on consecutive days (weekends and holidays excluded). The sham tDCS group will have 10 active or sham tDCS sessions. The sham group will have stimulation lasting only 40 seconds though the electrodes will remain in place for 20 min.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: tDCS; schizophrenia; cognition; fMRI