Cognitive Remediation Therapy for Schizophrenia: Effects on EEG and Emotional Regulation

Official title

A Randomized Controlled EEG-GSR Study on the Effects of Cognitive Remediation Therapy on Neurophysiological and Emotional Regulation Markers in Schizophrenia

Overview

This study aims to determine whether Cognitive Remediation Therapy (CRT) can improve attention, memory, and emotional regulation in people with schizophrenia. CRT is a structured program that includes exercises to strengthen cognitive skills such as problem-solving, working memory, and emotion regulation. The study will recruit 60 participants: 30 individuals with schizophrenia and 30 healthy individuals of similar age and gender. Those with schizophrenia will be randomly assigned to either receive CRT or be placed on a waitlist without therapy. All participants will undergo non-invasive brain activity (EEG) and emotional response (GSR) recordings before and after the therapy. The study's main question is: Does participating in a 12-week CRT program improve brain-based markers of attention and emotional regulation in people with schizophrenia? Additional tests, such as memory and emotion recognition tasks and self-report questionnaires, will help assess changes in thinking skills and emotional well-being. The study may help better understand how CRT affects both brain function and quality of life in schizophrenia.

Detailed description

This is a randomized controlled trial examining the effects of Cognitive Remediation Therapy (CRT) on neurophysiological and behavioral outcomes in schizophrenia. The primary goal is to assess whether CRT improves attentional control, sensory processing, executive function, and emotional regulation as measured by EEG and GSR.

Sixty participants will be enrolled: 30 individuals diagnosed with schizophrenia (DSM-5 criteria) and 30 healthy controls matched by age and gender. The schizophrenia group will be randomized into a CRT intervention arm and a waitlist control group. Healthy controls will not undergo CRT but will participate in baseline neurophysiological assessments to establish normative EEG and GSR values.

CRT will consist of 12 weekly sessions (approximately 60 minutes each), targeting cognitive domains such as working memory, attention, executive function, and emotion regulation using structured exercises and computer-based tasks.

EEG recordings will include P300 (oddball paradigm), mismatch negativity (MMN), and frontal theta power (cognitive control tasks). GSR will assess baseline skin conductance and reactivity to negative emotional stimuli. Behavioral tasks include the Stroop task, digit span, and facial emotion recognition.

Psychometric instruments include the Turkish-validated versions of:

* Difficulties in Emotion Regulation Scale (DERS) * Brief Assessment of Cognition in Schizophrenia (BACS) * Schizophrenia Quality of Life Scale (SQLS)

Primary outcomes will be assessed via pre- and post-test comparisons. Statistical methods include repeated-measures ANOVA, mixed-effects modeling, and regression analyses linking physiological changes to cognitive and emotional performance.

The study is ethically approved and aligns with international standards for human research.

Interventions

• Behavioral Cognitive Remediation Therapy
  CRT is a structured behavioral intervention consisting of weekly 60-minute sessions for 12 weeks. The therapy includes tasks to enhance cognitive skills such as attention, memory, executive function, and emotional regulation using computer-based training and therapist-guided exercises.

Primary outcome measures

• Change from Baseline in P300 Amplitude Measured via EEG at 12 Weeks [Time frame: Baseline and 12 Weeks Post-Intervention]

Secondary outcome measures (6)

• Change from Baseline in Mismatch Negativity (MMN) Amplitude Measured via EEG at 12 Weeks [Time frame: Baseline and 12 Weeks Post-Intervention]
• Change from Baseline in Frontal Midline Theta Power During Cognitive Tasks at 12 Weeks [Time frame: Baseline and 12 Weeks Post-Intervention]
• Change from Baseline in Skin Conductance Response (SCR) to Emotional Stimuli at 12 Weeks [Time frame: Baseline and 12 Weeks Post-Intervention]
• Change from Baseline in Difficulties in Emotion Regulation Scale (DERS) Total Score at 12 Weeks [Time frame: Baseline and 12 Weeks Post-Intervention]
• Change from Baseline in Brief Assessment of Cognition in Schizophrenia (BACS) Total Score at 12 Weeks [Time frame: Baseline and 12 Weeks Post-Intervention]
• Change from Baseline in Schizophrenia Quality of Life Scale (SQLS) Total Score at 12 Weeks [Time frame: Baseline and 12 Weeks Post-Intervention]

Eligibility criteria

Inclusion Criteria (Schizophrenia Group):

• Diagnosed with schizophrenia according to DSM-5 criteria
• Age between 18 and 55 years
• Clinically stable (no hospitalization or medication change within 1 month)
• Minimum primary school education
• Able to provide informed consent
• Right-handed (for EEG protocol consistency)

Inclusion Criteria (Healthy Control Group):

• No history of psychiatric or neurological disorders
• Age- and gender-matched to schizophrenia group
• No current medication affecting CNS
• Able to provide informed consent
• Right-handed

Exclusion Criteria (Both Groups):

• Current or past substance use disorder (within the past year)
• Comorbid neurological illness (e.g., epilepsy, traumatic brain injury)
• Current use of benzodiazepines or medications that significantly affect cognitive function
• Intellectual disability or MoCA score < 20
• Visual or hearing impairments that could interfere with task performance
• Participation in a psychological intervention in the last 3 months

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

Turkey (Türkiye) · 1 center

• Beykoz University — Istanbul

Identifiers

NCT: NCT06936397 · CRT-SCHZ-IST-2025

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗