Improving Visual Attention in Schizophrenia

The University of Texas System (UT)

Status: Completed

Conditions: Schizophrenia; Schizoaffective Disorder

Treatments: Device: Sham tDCS; Device: Active anodal tDCS

Study type: Interventional

Funder types: Other

Identifiers

NCT03880227

19-58

Details and patient eligibility

About

This study investigates whether visual attention can be improved in individuals with schizophrenia by stimulating the brain via transcranial Direct Current Stimulation (tDCS).

Full description

Individuals with schizophrenia tend to display abnormal visual attention when performing visual tasks, typically spending less time on salient features of the stimuli (e.g. core facial features or body movement in social tasks), and instead focusing on idiosyncratic features of an image or video. Poor visual attention in schizophrenia has been directly linked to poorer social cognitive performance (e.g. recognizing emotional expressions or social cues) which can impact an individual's day to day functioning.

Transcranial Direct Current Stimulation (tDCS) is a form of noninvasive neurostimulation which has been proposed as a therapeutic procedure in numerous psychiatric disorders. TDCS in schizophrenia has been demonstrated to improve a wide range of cognitive processes, and in healthy adults, tDCS has been demonstrated to improve aspects of social cognition. TDCS thus appears to be a promising therapeutic technique that may be useful for improving visual attention in patients with schizophrenia, and potentially impact social cognitive performance via an underlying mechanism tying the two. This study will compare visual performance in individuals with schizophrenia across two conditions: active anodal tDCS and sham tDCS, while also comparing between brain stimulation sites: rTPJ and dmPFC.

Enrollment: 81 patients

Sex: All

Ages: 18 to 60 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• DSM-IV-TR or DSM-5 diagnosis of schizophrenia or schizoaffective disorder and clinically stable (i.e. no hospitalizations) for at least 8 weeks prior to informed consent and be on a stable medication regimen for at least 6 weeks with no dose changes for a minimum of 2 weeks prior to informed consent.

Exclusion criteria

• The presence or history of a pervasive developmental disorder or mental retardation as defined by a premorbid IQ < 70
• Presence or history of medical or neurological disorders in which neural stimulation would be contraindicated (e.g. presence of epilepsy or history of seizures)
• Presence of sensory limitations, including visual or hearing impairments that interfere with assessment
• History of electroconvulsive therapy
• Not proficient in English
• Presence of substance abuse in the past one month or dependence not in remission in the past six months

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

---

81 participants in 4 patient groups

Anodal followed by sham stimulation tDCS to rTPJ

Experimental group

Description:

cross-over design - active stimulation tDCS to the rTPJ followed by behavioral testing. After 1 week washout, sham stimulation tDCS to the rTPJ followed by behavioral testing.

Treatment:

Device: Sham tDCS

Device: Active anodal tDCS

Anodal followed by sham stimulation tDCS to dmPFC

Active Comparator group

Description:

cross-over design - active stimulation tDCS to the dmPFC followed by behavioral testing. After 1 week washout, sham stimulation tDCS to the dmPFC followed by behavioral testing.

Treatment:

Device: Sham tDCS

Device: Active anodal tDCS

Sham followed by anodal stimulation tDCS to rTPJ

Experimental group

Description:

cross-over design - sham stimulation tDCS to the rTPJ followed by behavioral testing. After 1 week delay, active stimulation tDCS to the rTPJ followed by behavioral testing.

Treatment:

Device: Sham tDCS

Device: Active anodal tDCS

Sham followed by anodal stimulation tDCS to dmPFC

Active Comparator group

Description:

cross-over design - sham stimulation tDCS to the dmPFC followed by behavioral testing. After 1 week delay, active stimulation tDCS to the dmPFC followed by behavioral testing.

Treatment:

Device: Sham tDCS

Device: Active anodal tDCS