Depression can be among the most difficult illnesses to treat.
The first-line medications are drugs called selective serotonin reuptake inhibitors (SSRIs) like Prozac, Zoloft, and Lexapro. They are supposed to lift mood by increasing levels of serotonin, the “feel-good” compound, in the brain.
But SSRIs can take months to work, if they work at all. Or patients may have to spend years switching from one drug to another, trying to find the one that is effective for them.