Nearly 15 million Americans suffer from major depressive disorder, the leading cause of disability for adults between 18 and 44 years old, according to the National Institute of Mental Health. Worldwide, fewer than half get the treatment they need.
But a new kid on the serotonin block offers hope for an effective treatment: Last week, the Food and Drug Administration (FDA) approved Brintellix (vortioxetine), a serotonin reuptake inhibitor, for the treatment of major depression.
Major depressive disorder is characterized by symptoms – such as low mood, loss of interest, fatigue, insomnia, difficulty concentrating and changes in appetite – that persist every day for at least two weeks, says Dr. Michael Thase, professor of psychiatry at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia and one of the consultants who advised on the study of Brintellix by developers Takeda Pharmaceutical Company Limited (Takeda) and H. Lundbeck A/S (Lundbeck).
SSRIs lessen depression by altering naturally occurring chemical messengers called neurotransmitters, which are used to communicate between brain cells.
“It's a complex process,” Thase explains. “It's like putting a key into a lock: Once reuptake of serotonin is inhibited and more neurotransmitter is available in the synapse [an area that permits neurons to pass signals to other cells], changes happen in inside the neurons and in genes that affect the stress response, which in turn can improve mood and other related symptoms.”
All antidepressants have that potential, but what's different about Brintellix, Thase says, is that it has three other effects on other aspects of serotonin transmission, which might broaden its profile of response or lessen certain side effects – such as fewer sexual side effects — than currently available medications.
One study showed Brintellix might also help improve cognitive symptoms of depression, such as concentration, Thase says. But more studies are needed before the FDA will allow the company to advertise these potential secondary benefits.
Because major depression is so multifaceted, it's helpful for doctors to have a variety of options for treatment, Thase says.
“Although Brintellix primarily affects serotonin, like other widely used antidepressants, its particular profile is different than anything else we have,” he says. “But what you can't tell yet on the basis of the double blind studies is if these differences will be really important for our patients or if they'll be trivial in terms of extra benefits. It'll take some time to ascertain the extent these differences could make for patients.”