The World Health Organization (WHO) estimates that more than 350 million people suffer from depression worldwide. New research, as reported online in Neuropsychopharmacology on March 17th, points to a novel approach to treat this debilitating illness that the WHO considers to be the leading cause of disability worldwide.
In 2010, three-time NARSAD Grantee, Fang Liu, M.D., Ph.D., Senior Scientist and Section Head, Molecular Neuroscience Section, Neuroscience Research Department, Centre for Addiction and Mental Health (CAMH), Toronto, developed a protein peptide aimed at treating depression with a novel and highly targeted approach. The peptide treatment was found to interfere with the binding of two dopamine receptors in animal models; Dr. Liu’s team had found that this binding was higher in the brains of people with major depression and that disrupting the binding could offer antidepressant effects. Most antidepressant medications work by primarily blocking serotonin or norepinephrine transporters and the Canadian research team hypothesizes that a medication targeting the dopamine receptor complex may have fewer side effects.
In this earlier work, published in Nature Medicine in 2010, Dr. Liu and team demonstrated that when the protein peptide treatment was injected directly into the brain of rodents, there was an alleviation of depression-like symptoms in the animals. This peptide treatment offers a novel target, but the challenge for the team was to find a less invasive approach to deliver the new targeted medication. “Clinically, we needed to find a non-invasive, convenient method to deliver this peptide treatment,” said Dr. Liu. With additional funding from the Canadian Institutes of Health Research, she and her team were able to conduct new experiments to further explore novel delivery methods, leading to the development of a nasal spray.
The researchers report that the nasal spray effectively delivered the peptide to the targeted brain areas in animal models and alleviated depression-like symptoms for at least two hours after administration. Dr. Liu and team are now conducting further experiments to see if it is possible to make the peptide travel more quickly to the brain and improve its antidepressant effects.