Water Test Used on Patients with Schizophrenia, by CAMH Researchers, to Make Them Aware of Their Illness

A commonly used test of the balance system, involving water in the ear to indirectly stimulate the brain, may bring a temporary awareness of illness to people with schizophrenia who feel they are not ill, according to new research from CAMH.

Patients with schizophrenia, a long-term mental health problem that affects the way a person understands and interacts with the world, sometimes go off their treatment plan because they perceive they’re not ill. This can result in relapse.

However, a new approach shows promise to avoid this problem, at least in the short-run: Doctors at the Centre for Addiction and Mental Health (CAMH) have been studying the use of a water test ‒ commonly used by ear, nose and throat specialists, and audiologists to test patients’ balance ‒ and applied this to patients with schizophrenia. In a proof-of-concept study, researchers showed that this test, which uses water of varying temperatures in the ear to indirectly stimulate the brain, brought a temporary awareness of illness to people with schizophrenia, in the same way it has worked for stroke patients.


“Poor insight into illness in schizophrenia is a huge problem and can have a direct impact on treatment adherence and clinical outcomes,” said Dr. Philip Gerretsen, a geriatric psychiatrist and clinical fellow at CAMH who led this research. The health of these patients can suffer, he emphasized in an interview with Medscape Medical News. People with untreated symptoms of schizophrenia may experience delusions, hallucinations and become socially withdrawn.

About 1% of the Canadian population develops schizophrenia. In 2004, this translated to 234,305 persons, according to a 2005 article in Current Medical Research and Opinion on the economic burden of schizophrenia in Canada.

The direct health-care and non-health-care costs were estimated to be just over $2 billion, in this article, which also reported that there were 374 deaths attributed to schizophrenia. This combined with the high unemployment rate due to schizophrenia resulted in a total cost estimate of $6.85 billion (2004).

Water Test on Stroke Patients Leads to Increased Awareness

Anosognosia is the name of the condition at play in cases where patients cannot recognize their illness. This is viewed as a lack of self-awareness. Many people with schizophrenia, dementia and strokes have this condition. Some stroke patients, for example, don’t realize that they have been paralyzed.

The water test, called caloric vestibular stimulation (CVS), involves putting water into the patient’s ear canal to stimulate different areas of the brain. The effect of the stimulation varies depending on the temperature of the water and which ear is being irrigated.

“Warm water in the right ear stimulates the ipsilateral [right] hemisphere, cold water stimulates the contralateral [left] hemisphere,” Gerretsen further explained in the Medscape interview. The stimulation is visible in brain imaging studies (PET and MRI scans).

patient having calorics 2
Patient undergoing caloric vestibular stimulation (CVS). Image provided by Cambridge University Hospitals, School of Clinical Medicine http://bit.ly/1t3JL1T.

This water test has already been successfully employed in the case of stroke patients: “Research has shown that cold water in the left ear of stroke patients with right hemisphere damage can reverse the lack of awareness of paralysis, so that they gain awareness from 30 minutes to as much as two hours after the test that they have neurological deficits,” Gerretsen explained in a CAMH article.

Researchers Conduct Water Test on 13 Patients with Schizophrenia

Seeking to apply this to patients with schizophrenia, Gerretsen, along with his co-investigator, the University of Toronto’s Dr. David Pothier, launched a pilot proof-of-concept study funded by the Ontario Mental Health Foundation.

They tested CVS in 13 patients (10 men and three women) with schizophrenia, who had moderate to severe insight impairment. The patients’ mean age was 41 years, mean age at illness onset was 26 years, and mean duration of illness was 16 years.

The study participants were given one of three tests:

(1) cold CVS in the left ear with a water temperature of 4° C;
(2) cold CVS in the right ear with a water temperature of 4° C; and
(3) sham (fake or placebo) CVS, where the water was at body temperature. At five, 30 and 60 minutes after the test, the researchers assessed the patients’ insight into their illness, using the VAGUS Insight into Psychosis Scale, designed to capture subtle changes in insight over a short period of time.

The researchers found that CVS with cold water in the left ear significantly increased the patients’ insight and awareness of their illness at 30 minutes after the test, compared to the sham and right ear, cold water treatments. However, this did not last long; by 60 minutes, this insight faded.

Looking ahead, Gerretsen hopes to undertake further research to find ways to extend the period of awareness. He told Medscape, “Our hope would be to move the CVS approach to perhaps five consecutive days of stimulation and see if we can have more enduring effects.”

Gerretsen presented the results at the American Society of Clinical Psychopharmacology 2014 Annual Meeting in June.

To read the CAMH article: http://bit.ly/1uXsN6s. To consult CAMH’s fact sheet on schizophrenia: http://bit.ly/1oWqYGD. To see the Medscape article: http://bit.ly/1BkiOwr. To read the Current Medical Research and Opinion article: http://1.usa.gov/1tYPuKj.