None listed
Conditions
Brief summary
Working memory difficulties are commonly experienced by individuals with schizophrenia and schizoaffective disorder. These difficulties have been shown to negatively influence patients’ psychosocial functioning. Any technique that may enhance working memory would therefore be very useful. Recent research has suggested that brain stimulation, and in particular transcranial Electrical Stimulation (TES) techniques such as transcranial Direct Current Stimulation (tDCS) and transcranial Alternating Current Stimulation (tACS), may have a role to play in improving cognition. TES techniques have been shown to be a safe and non-invasive way of modulating brain activity, by applying a very weak electrical current (1-2mA) to the cortex via electrodes that are placed on the scalp. While tDCS has been shown to improve working memory in a number of conditions, to date there have been no tDCS or tACS studies looking at the enhancement of working memory in schizophrenia. The current study will investigate whether working memory can be improved using tDCS and tACS in healthy participants and patients with schizophrenia or schizoaffective disorder. Further, the study aims to establish the most effective stimulation parameters for optimal working memory enhancement. Twenty healthy controls and 20 individuals with schizophrenia or schizoaffective disorder will attend 3 sessions at The Alfred hospital, each session involving a different type of TES (1mA tACS, 2ma tDCS, or sham stimulation). Participants' performance on a working memory task will be assessed following application of the stimulation, and brain activity will be monitored throughout the tasks using electroencephalography (EEG).
Interventions
Anodal transcranial direct current stimulation (tDCS) at 2mA intensity, and anodal transcranial Alternating Current Stimulation (tACS) at 1mA intensity with gamma frequency range of 30-40Hz. This will be applied to the left dorsolateral prefrontal cortex for 20 minutes using a neuroConn GBH/Eldith DC Stimulator. tDCS will be delivered during three sessions (one tDCS, one tACS, and one sham tDCS) that will be one week apart.
Sponsors
Dr. Kate Hoy
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used)
Eligibility
Sex/Gender
All
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
Participants with schizophrenia will be included if they: - are voluntary and competent to consent - have a diagnosis of Schizophrenia or Schizoaffective Disorder as confirmed by the Structure Clinical Interview for the DSM-IV (SCID-IV) Healthy individuals will be included if they: - have capacity to consent - have no personal history of psychiatric illness (lifetime) - based on self report.
Exclusion criteria
Patients with schizophrenia will be excluded if they: - have a a DSM-IV history of substance abuse or dependence in the last 6 months - have a concomitant major and/or unstable medical or neurologic illness - are currently taking carbamazepine - are currently pregnant or lactating - have metal anywhere in the head, except the mouth (this includes metallic objects such as screws and clips from surgical procedures) Healthy participants will be excluded if they: - have an unstable medical condition, neurological disorder or are currently pregnant or lactating - have metal in the cranium, a pacemaker, cochlear implant medication pump or other electronic device
Outcome results
None listed