The study, conducted by McGill University, has found that a new class of drugs known as serotonin4 (5-HT4) receptor agonists may take effect four to seven times faster than traditional selective serotonin reuptake inhibitors (SSRIs).
The study was led by former McGill post-doctoral fellow in psychiatry Guillaume Lucas and his supervisor, the late Dr. Guy Debonnel.
Existing SSRI-class drugs, widely prescribed as anti-depressants, can take up to six weeks to become effective, with potentially serious clinical consequences.
"These delays are not only a matter of patient comfort, it's really important, especially when you are treating major depressions that could lead to suicide," said Dr. Lucas, now an associate researcher at the Centre de Recherche Fernand Seguin of Universite de Montreal.
SSRIs work by improving the available concentration of the neurotransmitter serotonin in the brain. The McGill study focused on a new class of drugs known as serotonin4 (5-HT4) receptor agonists, which act directly on the nerve impulses of serotonin neurons.
In the study, rats on two different serotonin4 receptor agonists showed marked improvements in symptoms of chronic depression after only three days and were symptom-free after a week.
In subsequent tests, three days of treatment with serotonin4 receptor agonists induced anti-depressant-related effects in the brains of the animals seen only after weeks of treatments with SSRIs.
The study is published in the September 6 issue of the journal Neuron.