Schizophrenia
Conditions
Brief summary
This is a double-blind sham-controlled study to evaluate the effects of the combination of non-invasive brain stimulation, i.e. transcranial direct current stimulation (tDCS), with brief cognitive training (CT) on cognition in patients with schizophrenia. All participants will practice the same cognitive training tasks and will be randomised to either real tDCS or sham stimulation. Patients with schizophrenia will undergo the study interventions while maintaining their standard treatment with antipsychotic medications.
Interventions
Sponsors
King's College London
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
No
Inclusion criteria
* DSM-IV diagnosis of schizophrenia or schizoaffective disorder * Treatment with stable doses of antipsychotic medications. For the purpose of this study stability is defined as a not more than 50% change in the dose of their antipsychotic medication 3 months preceding the screening visit. * Age between 18 and 55 years * Written and witnessed informed consent * Participants must read and write in English at a level sufficient to understand and complete study-related procedures
Exclusion criteria
DSM-IV diagnosis of alcohol or drug dependence in the 6 months, current treatment with benzodiazepines or hypnotics * Current or past skin disease * History of a neurological disorder or a systemic illness with known neurological complications; including epilepsy * History of seizures * Head injury, accompanied with loss of consciousness or/and required hospitalization * Unwillingness or inability to follow or comply with the procedures outlined in the protocol
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| The change in neuronal activity during an executive functioning task response to real tDCS vs sham stimulation. | 1 day | A comparison of neural blood oxygen level-dependent (BOLD) response during an executive function task in the real tDCS vs sham stimulation. |
| Does the combination of tDCS with brief working memory training will enhance the learning capacity of the research participants compared to sham stimulation, and whether the learning rates will be retained in the longer-term | 56 days | The change in learning on a working memory training tasks will be analyzed using a full maximum likelihood-random effect multilevel models (MLREM). The MLREM will include the working memory outcome measure during the tDCS, next day retention at the session following tDCS administration and longer-term retention; controlled for baseline performance with fixed categorical effects for group (real tDCS vs sham stimulation) and time (0-4); an interaction of time and group. |
| Does the combination of tDCS with brief stochastic learning training will enhance the learning capacity of the research participants compared to sham stimulation, and whether the learning rates will be retained in the longer-term | 56 days | The change in learning on a stochastic training tasks will be analyzed using a full maximum likelihood-random effect multilevel models (MLREM). The MLREM will include the stochastic learning task outcome measure during the tDCS, next day retention at the session following tDCS administration, and longer-term retention; controlled for baseline performance with fixed categorical effects for group (tDCS vs sham stimulation) and time (0-4); an interaction of time (0-4) and group. |
| Does the combination of tDCS with brief implicit learning training will enhance the learning capacity of the research participants compared to sham stimulation, and whether the learning rates will be retained in the longer-term | 56 days | The change in learning on an implicit training tasks performance will be analyzed using a full maximum likelihood-random effect multilevel models (MLREM). The MLREM will include the task outcome measure during the tDCS administration, next day retention at the session following tDCS administration, and longer-term retention; controlled for baseline performance with fixed categorical effects for group (real tDCS vs sham stimulation) and time (0-3); an interaction of time (0-3) and group. The MLREM model will exclude the second acute tDCS session, as the task design was optimized fMRI. |
| The change in neuronal activity during a working memory task in response to real tDCS vs sham stimulation. | 1 day | A comparison of neural blood oxygen level-dependent (BOLD) response during a working memory task in the real tDCS vs sham stimulation. |
| The change in neuronal activity during a stochastic learning task in response to real tDCS vs sham stimulation. | 1 day | A comparison of neural blood oxygen level-dependent (BOLD) response during a stochastic learning task in the real tDCS vs sham stimulation. |
| The change in neuronal activity during an implicit learning task in response to real tDCS vs sham stimulation. | 1 day | A comparison of neural blood oxygen level-dependent (BOLD) response during an implicit learning memory task in the real tDCS vs sham stimulation. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| The secondary outcome measure is going to be the generalization of learning to non-trained task. | 3 years | The secondary outcome measure is the generalization of learning to non-trained task, indexed by the CogState neuropsychological battery. We will test if the effects of cognitive training and real tDCS would generalize onto significant performance improvements on related cognitive domains of executive function, and attention and vigilance as measured by the CogState neuropsychological assessment battery. The between group (1-realtDCS/ 0-sham stimulation) differences on these tasks will be tested using regressions, controlled for baseline performance. |
Outcome results
None listed