In a new study, researchers from the University of Illinois at Chicago and Massachusetts General Hospital have found that stem cells derived from adult patients can be used to model major depressive disorder (MDD) and test how patients respond to drug treatment. They found that when tested in this model, fish oil produced an antidepressant response.
The study offers some new findings that could help scientists better understand how the brain works and why some people respond to medication for depression, while others get limited benefit from antidepressants, said Mark Rasenick of the University of Illinois at Chicago, a co-corresponding author of the paper.
Rasenick says, “It’s also exciting to find scientific evidence that fish oil – an easily available natural product – may be an effective treatment for depression.”
Major depressive disorder is the most common mental illness. About one in six people will experience at least one depressive episode in their lifetime. However, antidepressant treatment fails in about one-third of patients.
In this new study, these researchers used skin cells from adult depressed patients that were transformed into induced pluripotent stem cells (iPS) at Massachusetts General Hospital. iPS cells were then induced to give rise to induced neural stem cells (iNSC). After further induction, iNSC differentiate into astrocytes. Skin biopsy samples were taken from two types of patients: those who had previously responded to antidepressants and those who had previously been resistant to antidepressants. When tested using fish oil, models from both antidepressant-sensitive and antidepressant-resistant patients responded.
The response was similar to that observed from prescription antidepressants, but it was produced through a different mechanism, Rasenick said.
We see that fish oil acts partially on astrocytes, not neurons,” Rasenick said. For years, scientists have paid little attention to astrocytes — a type of brain cell located around neurons — but there is growing evidence that astrocytes may play a role in depression. Our study suggests that astrocytes may also be important for antidepressant effects. Our study also suggests that stem cell models can be used to study post-treatment responses and that fish oil warrants further study as a treatment or adjunct to treatment for depression.”