A molecule found only in the brains of humans and primates could be linked to depression.
Researchers found depressed individuals tend to have lower levels of a molecule called miR-1202, a McGill University news release reported. The finding could lead to better treatments for patients struggling with depression.
Finding the right depression treatment for each patient can be tricky, and involves plenty of trial and error. This molecule could act as a marker to predict which patients will respond to which medication.
"Using samples from the Douglas Bell-Canada Brain Bank, we examined brain tissues from individuals who were depressed and compared them with brain tissues from psychiatrically healthy individuals," Doctor Gustavo Turecki, a psychiatrist at the Douglas and professor in the Faculty of Medicine, Department of Psychiatry at McGill, said in the news release. "We identified this molecule, a microRNA known as miR-1202, only found in humans and primates and discovered that it regulates an important receptor of the neurotransmitter glutamate."
The researchers conducted a number of experiments that showed antidepressants changed microRNA levels.
"In our clinical trials with living depressed individuals treated with citalopram, a commonly prescribed antidepressant, we found lower levels in depressed individuals compared to the non-depressed individuals before treatment," Turecki said. "Clearly, microRNA miR-1202 increased as the treatment worked and individuals no longer felt depressed."
Antidepressant drugs are the most common treatment for the condition, they are also the most prescribed drugs in North America.
"Although antidepressants are clearly effective, there is variability in how individuals respond to antidepressant treatment," Turecki, said. "We found that miR-1202 is different in individuals with depression and particularly, among those patients who eventually will respond to antidepressant treatment."
The discovery could provide a "potential target for the development of new and more effective antidepressant treatments," the researchers said in the news release.
