There is potential for a new tool in the fight for better mental health.
About 30% of patients do not get better by taking anti-depressants, but why? Local researchers are looking in the blood for answers, not just to diagnose the disease but to help determine if medications are working properly.
It’s been neuroscientist Mark Rasenick’s life’s work. After 40 years, there’s been a potential breakthrough in a tube of blood.
“About half of the people who are depressed don’t seek treatment and the reason they don’t seek treatment there is stigma, social justice issue,” he said. “And now we can say it’s not just in your head, it’s in your blood.”
What the University Illinois – Chicago distinguished professor and his team found in the platelets of patients with depression was a protein stuck in its tracks.
“We developed this system looking at a particular protein and how it either gets stuck when you are depressed or liberated when you are treated correctly,” he said.
It’s called a G-protein and it sits in the membrane of a platelet or nerve cell. Its job is to relay messages from hormones and neurotransmitters — like serotonin and epinephrine — to the inside of the cell. In a small proof of concept study, Rasenick and his team looked at blood samples from patients taking the same amount of anti-depressant medication. In those who improved, the G-protein broke free. In those who didn’t improve, it remained stuck in the cell membrane, unable to convey the neurotransmitter’s signal.
“What happens if it gets stuck, it doesn’t work the way it’s supposed to,” he said. “So when it gets unstuck, it goes to another enzyme and makes the neurotransmitter work the way it’s supposed to and the way it would do normally if you are not depressed.”
Rasenick hopes his biomarker blood test will be beneficial for patients deemed treatment-resistant, meaning various drugs haven’t helped ease symptoms. That’s because platelets turn over every week, giving clinicians an opportunity – with a simple blood draw — to quickly determine which drugs are working to unstick the G-protein.
“The idea would be if we see in a week (and) you are not responding well, let’s try something else or lets add something. Let’s not wait two months and let you suffer,” Rasenick said. “If we can change the way that depression is treated and we can help to eradicate the stigma that people who are depressed feel, I like to say it’s my mitzvah project, which means ‘good deed’ in Hebrew. And I really feel that way.”
The next step is to test the blood test, called the mood mark, in a larger group of patients. The researchers also hope to experiment with medications directly on the platelets in the lab to see which ones unstick the protein.