Clinical trial NCT03872310: Cognitive Enhancement on Working Memory in Patients With Schizophrenia
Official title: A Study of Cognitive Enhancement of Transcranial Direct Current Stimulation on Working Memory in Patients With Schizophrenia
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Memory Deficits
Schizophrenia
Neurostimulator; Complications
Keywords: Schizephrenia
Cognitive enhancement
Transcranial direct current stimulation
Non-invasive brain stimulation
Working memory
Lead sponsor: Taipei Medical University Shuang Ho Hospital
Sponsor class: OTHER
First posted: 2019-03-13
Enrollment: 28
Sex: ALL
Minimum age (years): 20
Maximum age (years): 55
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief summary: The investigators plan to investigate the effect of enhancement on working memory (WM) in patients of chronic schizophrenia and determine the predictive factors of effective treatment.

Detailed description: Schizophrenia is a chronic and disabling disease with a prevalence of 0.5%\~1.5% in the general population. It's estimated 98% of patients with schizophrenia exhibit variable degrees of cognitive deficits which have been well established to be predictive of patient functioning. A number of treatments had been developed for cognitive enhancement in patients with schizophrenia, nevertheless none of them showed satisfying results.

Transcranial direct current stimulation (tDCS) is a safe and convenient treatment which has showed some evidence of beneficial effects on working memory (WM) in both healthy and neuropsychiatric populations. However, studies of tDCS for cognitive enhancement in patients with schizophrenia are still quiet limited. The results of our previous studies in healthy participants and patients with diabetic polyneuropathy suggest that the anodal tDCS over right dorsolateral prefrontal cortex (DLPFC) improved spatial WM capacity, particularly when task difficulty demands more complex mental manipulations and for the low-performing patients in baseline assessments. Thus, we hypothesize that in the baseline the more severe the patients' cognitive deficit are, the greater their WM capacity improvement would be after applying the anodal Tdcs over right DLPFC.

The investigators plan to recruit 40 patients with chronic schizophrenia. First, the investigators will collect baseline characteristics including disease severity, cognitive deficits and brain connectivity. Then the investigators will adopt a sham-active crossover design for tDCS treatment with the order of the two sessions (sham and active) counterbalanced across participants. The investigators will perform pre- tDCS and post- tDCS assessments of their spatial WM and verbal WM as well as statistical analyses to see if the effect of cognitive enhancement reaches a significant level. In addition, the investigators will explore the possible predictive indicators of effective treatment.

Eligibility criteria: Inclusion criteria

1. Inform consent acquired
2. Age 20 to 50
3. Right-handed
4. Patients with schizophrenia diagnosed according to DSM-5 criteria

Exclusion criteria

1. Participants who are pregnant or breastfeeding
2. Participants who have metal implants
3. Participants who have alcohol/substance use disorder or received electro-convulsive therapy within the past 6 months.
4. Participants who have history of head injury with loss of consciousness
5. Participants who have history of brain lesions, infection, or epilepsy
6. Skin lesions on the electrodes placed
7. Cancer patients
8. Patients with high fever
9. Patients with significant sensory loss

Primary outcomes:
measure: Visual-spatial working memory span measured by Corsi Block-Tapping task
timeFrame: up to one hour
measure: Verbal working memory measured by digit-span test
timeFrame: up to one hour
Secondary outcomes:
Other outcomes:
Locations:
city: Taipei
country: Taiwan
facility: Shuang-Ho Hospital
Study officials:
affiliation: Taipei Medical University Shuang Ho Hospital
name: Jiunn-Kae Wang, MD
role: PRINCIPAL_INVESTIGATOR
References: