Study device no longer available.

This study aims to determine the clinical and functional imaging effects of serial CVS on illness awareness in schizophrenia. Specifically, the investigators aim to:

1. Determine if twice-daily CVS for 4 weeks will improve illness awareness compared to the sham condition in participants with schizophrenia. Illness awareness will be assessed at pre- and post-CVS, and weekly thereafter for 4 weeks.
2. Examine changes in brain network activity (blood oxygen level dependent-BOLD in response to an illness awareness task) pre- and post-CVS. This will serve as a biomarker to rigorously test whether repeated CVS engages the PPA associated with illness awareness.

The proposed study employs a novel approach to determine the clinical and functional imaging effects of CVS on illness awareness in schizophrenia - a significant contributor to medication non-adherence and poor treatment outcomes, and arguably the most treatment resistant manifestation of the disorder. CVS is a traditionally safe and non-invasive method of vestibular stimulation that will be used in conjunction with a neuroimaging biomarker to measure brain changes associated with CVS and illness awareness. The results of this study will provide solid evidence for larger treatment-controlled effectiveness studies to determine if CVS is a practical means of producing lasting effects on illness awareness in individuals with schizophrenia or whether maintenance CVS treatment is required.

Inclusion Criteria:

1. Male or female inpatients or outpatients ≥ 18 years of age
2. Having a DSM-V diagnosis of schizophrenia or schizoaffective disorder
3. Voluntary and capable of consenting to participation in the research study
4. Fluent in English
5. Moderate-to-severe lack of illness awareness ≤7 on the VAGUS-SR, which corresponds to a rating of ≥3 on PANSS G12 Insight and Judgment item)
6. On a stable dose of antipsychotic and other concomitant medications for at least 2 months, and unlikely to undergo changes in dose during the study

Exclusion Criteria:

1. Unwilling or unable to consent to the study
2. Use of hearing aids or cochlear implants, chronic tinnitus, temporomandibular joint disease
3. Had eye surgery within the previous three (3) months
4. Ear surgery within 6 months prior to entering the study
5. Active ear infection or perforated tympanic membrane
6. Diagnosis of vestibular dysfunction
7. Unstable medical illness or any concomitant major medical or neurological illness, including a history of cardiovascular disease and seizures
8. Acute suicidal and/or homicidal ideation
9. Formal thought disorder rating ≥4 on PANSS item P2
10. DSM-V substance dependence (except caffeine and nicotine) within one month prior to entering the study
11. Positive urine drug screen at the screening visit
12. Metal implants or a pacemaker that would preclude the MRI scan
13. Pregnancy