More than half of patients with schizophrenia have poor insight into their condition, meaning that they do not believe they are ill. This lack of insight is a primary reason why many patients refuse to seek treatment or regularly take medication. The result is poorer health as well as a higher likelihood of being hospitalized or experiencing housing instability.
A new study at the Centre for Addiction and Mental Health shows that a balance test that stimulates part of the brain — using cold water through the left ear — can temporarily alleviate this lack of insight.
Dr. Philip Gerretsen, a clinician-scientist in the Campbell Family Mental Health Research Institute devised the idea of using this test for schizophrenia based on promising results among paralyzed patients with stroke damage who lacked awareness of their paralysis.
The test, called caloric vestibular stimulation, involves irrigating the ear canal with water at varying temperatures. The test is commonly used to assess the body’s vestibular or balance system. The procedure can stimulate different areas of the brain, including specific regions associated with lack of insight, a connection which has been confirmed by brain imaging studies.
In stroke patients with right hemisphere damage, cold water led to a temporary awareness of their paralysis. The new new findings of using the procedure among people with schizophrenia were promising.
“Cold water in the left ear significantly increased patients’ insight and awareness of their schizophrenia, which we measured 30 minutes after the test, compared with the sham or placebo treatment using room temperature water,” said Gerretsen. Shortly after the treatment was administered, however, this insight had diminished.
In the right ear, the cold water treatments appeared to have the opposite effect — they worsened insight in people with schizophrenia.
The researchers used the water procedure on 16 patients with schizophrenia spectrum disorder, who had moderate to severe lack of insight into their illness. The participants were given, in a random order, one of three conditions: cold water at 39.2°F (4°C) in their left ear, cold in their right ear, and a sham procedure in which the water was at body temperature.
Patients’ insight into their illness was assessed at 30 minutes after the test, using the VAGUS Insight into Psychosis Scale, a measure designed to capture subtle changes in insight over a short period of time.
“With these promising results, we’re embarking on new research aiming to make the period of awareness last longer, using a new device that makes the procedure much more convenient,” says Dr. Gerretsen.
Gerretsen is testing a new device, a vestibular stimulation headset with temperature-controlled earpieces. Unlike the water test, this device was designed for home use and doesn’t require water or a trained specialist to administer. Study participants will use the procedure for several consecutive days to see if it leads to a sustained improvement in illness insight.
The study was published in the journal Psychiatry Research.