March 25, 2014
Depression May One Day Be Treated With A Peptide Nasal Spray
April Flowers for redOrbit.com - Your Universe Online
A new study from the Center for Addiction and Mental Health (CAMH) reveals that a nasal spray which delivers a peptide designed to treat depression holds promise as a potential alternative to traditional therapies.
CAHM's Dr. Fang Liu, in a previous study published in Nature Medicine in 2010, detailed a protein peptide she developed that provided a highly targeted approach to treating depression. Dr. Liu hopes this peptide will have minimal side effects. In animal testing, the peptide was proven to be just as effective in relieving symptoms when compared to a conventional antidepressant. There was one issue, however. Taken orally, the peptide would not cross the blood-brain barrier, therefore, it had to be injected into the brain.
"Clinically, we needed to find a non-invasive, convenient method to deliver this peptide treatment," said Dr. Liu, Senior Scientist in the Campbell Family Mental Health Research Institute at CAMH. Liu's team was able to continue researching new delivery methods because of a Proof of Principle grant from the Canadian Institutes of Health Research (CIHR).
Impel NeuroPharm developed the nasal delivery system, which was shown to deliver the peptide to the correct region of the brain where it proved effective at relieving depression-like symptoms in animals.
"This study marks the first time a peptide treatment has been delivered through nasal passageways to treat depression," said Dr. Liu, who is also a Professor in the University of Toronto's Department of Psychiatry.
According to a statement released by CAMH, "The peptide treatment interferes with the binding of two dopamine receptors – the D1 and D2 receptor complex. Dr. Liu's team had found that this binding was higher in the brains of people with major depression. Disrupting the binding led to the anti-depressant effects."
Depression treatments have primarily depended on medications that primarily block serotonin or norepinephrine transporters, making the peptide an entirely new approach.
One of the leading causes of disability globally, depression is the most common form of mental illness. Over 50 percent of those living with the condition do not respond to first line medication treatments.
"This research brings us one step closer to clinical trials," said Dr. Liu. Her team is continuing their research with experiments to determine if they can make the peptide break down more slowly, and travel more quickly in the brain, to improve its anti-depressant effects.
The findings were published online in the journal Neuropsychopharmacology.