Research Challenges the Way Antidepressants Work
Research in rats has shown that antidepressants such as SSRIs (selective serotonin reuptake inhibitors) or SNRIs (selective norepinephrine reuptake inhibitors) elevate serotonin levels in the brain. The biochemical events can be measured, but the psychological effects are less well known—for example, how people handle their emotions and how this might translate into improved moods.
"When people are depressed, they have a bias toward negative responses and feelings. They may feel, for example, that their work colleagues are hostile toward them, creating a downward spiral of misery and anxiety," Cowen said.
In their randomized, double-blind study, 42 healthy men and women who did not have depression were given SSRIs, SNRIs, or a placebo for seven days. After a few days of treatment with SSRIs, their emotional outlooks became more positive (based on performance on tasks of emotional processing). These positive biases in emotional processing were independent of their reported mood.
"The drugs work quickly to change how people experience the world emotionally. We believe this is due to the effect of the drugs on emotional processing, rather than directly altering mood. Remembering and experiencing events in a more positive light helps to lift a person out of their depression," Cowen said.
The way the antidepressants work is compatible with cognitive behavioral therapy, suggesting that people with depression may benefit from both antidepressants and cognitive behavioral therapy.