EEG Outcomes From Cognitive Behavioural Therapy for Psychosis

NCT ID: NCT05703698

Last Updated: 2025-07-29

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 20 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-02-01
• Study Completion Date: 2024-11-13

Brief Summary

Despite overwhelming evidence for neurocognitive and neurophysiological factors involved in the etiology of psychosis, these factors have never been examined as mechanisms of improvement from CBTp. The first aim in the present study is to examine neurophysiological outcomes from CBTp using electroencephalography (EEG). The second aim is to examine neurocognitive outcomes from CBTp. This is an open-label pilot study. Twenty participants will receive CBTp and will be assessed at baseline and after 4 months.

Detailed Description

Despite decades of refining traditional treatments for schizophrenia-spectrum disorders, recovery rates remain unchanged at only 13.5%, and there is an urgent need for innovative new interventions. Cognitive behavioural therapy has more recently been applied to treating psychosis and initial evidence has suggested that cognitive behavioural therapy for psychosis (CBTp) is the most effective psychosocial intervention available for psychosis. However, the efficacy of CBTp has been limited to moderate effect sizes. Little is currently understood about the mechanisms of CBTp, and a greater understanding of mechanisms is necessary in order to improve treatment efficacy. Despite overwhelming evidence for neurocognitive and neurophysiological factors involved in the etiology of psychosis, these factors have never been examined as mechanisms of improvement from CBTp. Cognitive behavioural therapy for psychosis (CBTp) has demonstrated efficacy for reducing positive symptoms, negative symptoms, and improving community functioning6 for individuals diagnosed with psychotic disorders. Despite meta-analytic evidence for the efficacy of CBTp, little is known about the neurophysiological processes through which symptomatic and functional change occurs. Electroencephalography (EEG) provides temporally precise measurement of neurophysiological activity. Positive symptoms have been associated with reduced integration of discrepant information as indexed by the N400 event-related potential, reduced resting state power in the EEG alpha frequency band, and reduced cognitive control as indexed by EEG alpha and theta power during cognitive flanker tasks. Additionally, neurocognitive abilities such as attention, memory, and problem solving are the best predictors of community functioning among individuals diagnosed with psychotic disorders. Although CBTp improves community functioning,[6] neurophysiological and neurocognitive outcomes have never been examined as therapeutic mechanisms from CBTp, despite the fact that therapeutic processes would be expected to improve cognitive functions.

Aim 1: Examine neurophysiological outcomes from CBTp using EEG.

Aim 2: Examine neurocognitive outcomes from CBTp

Hypothesis 1: After CBTp it is expected that participants will have a) increased N400 amplitude; b) increased resting state EEG alpha power; and c) reduced alpha and increased theta power during a flanker task

Hypothesis 2: After CBTp participants will have increased global neurocognitive abilities as indexed by a neurocognitive composite score.

Although CBTp has demonstrated efficacy to improve symptoms for individuals experiencing psychosis, little is known about the neurophysiological process through which this improvement occurs, and neither EEG nor neurocognitive outcomes from CBTp have ever been examined. The current results will provide preliminary evidence for neurophysiological mechanisms of change from CBTp that will increase understanding of the disorder and provide critical insights for refining psychotherapeutic interventions. Additionally, psychotherapy trials typically only examine psychological outcomes, however, if CBTp is effective it would be expected that this could be detected at both the neurophysiological level and neurocognitive level as well. My incorporation of multiple levels of assessment in clinical trials was recently praised as a goldstandard approach to trial methodology. This line of research is critical to improving the efficacy of CBTp.

Conditions

Psychotic Disorders; Schizophrenia and Related Disorders

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Cognitive Behavioural Therapy for psychosis

CBTp will be delivered according to an established manual that the PI has previously used successfully for in-person treatment. Treatment will consist of individual sessions with a psychologist employed by the University of Toronto for 1-hour per week for 6-months, or by one of the listed clinical graduate students under his supervision. All treatment will be delivered in-person. This treatment will be delivered in addition to usual care and no changes to usual care will be required.

Group Type: EXPERIMENTAL

Cognitive Behavioural Therapy for Psychosis

Intervention Type: BEHAVIORAL

CBT will be delivered according to an established manual that the PI has previously used successfully for in-person treatment. Treatment will consist of individual sessions with a psychologist employed by the University of Toronto for 1-hour per week for 6-months, or by one of the listed clinical graduate students under his supervision. All treatment will be delivered in-person. This treatment will be delivered in addition to usual care and no changes to usual care will be required.

Interventions

Cognitive Behavioural Therapy for Psychosis

CBT will be delivered according to an established manual that the PI has previously used successfully for in-person treatment. Treatment will consist of individual sessions with a psychologist employed by the University of Toronto for 1-hour per week for 6-months, or by one of the listed clinical graduate students under his supervision. All treatment will be delivered in-person. This treatment will be delivered in addition to usual care and no changes to usual care will be required.

Intervention Type: BEHAVIORAL

Other Intervention Names

CBT; CBTp

Eligibility Criteria

Inclusion Criteria

Inclusion Criteria:

• The inclusion criteria is anyone who meets the criteria of schizophrenia, schizoaffective disorder or any other psychotic disorder, are also 18-65 years of age, are not abusing drugs or alcohol and can read and speak English. Participants must be experiencing active symptoms of psychosis as indicated on the PANSS.

Exclusion Criteria:

• Exclusion criteria include anyone with a neurological disease or neurological damage, medical illnesses that can change neurocognitive function, a medical history of head injury with loss of consciousness and those with physical handicaps that would prevent them from engaging in assessment procedures

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Ontario Shores Centre for Mental Health Sciences

OTHER

Sponsor Role: collaborator

University of Toronto

OTHER

Sponsor Role: lead

Responsible Party

Michael Best

Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Michael W Best, Ph.D.

Role: PRINCIPAL_INVESTIGATOR

University of Toronto

Locations

University of Toronto Scarborough

Scarborough Village, Ontario, Canada

Countries

Canada

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Other Identifiers

38831

Identifier Type: -

Identifier Source: org_study_id