Antidepressants Aren't Just Affecting Mood

Successive clinical trials have confirmed that SSRI drugs are effective for around two-thirds of patients. But what is puzzling is that, while these drugs alter serotonin levels in the brain almost immediately, they typically take two to four weeks to have a clinical benefit. Professor Katherine Harmon has been investigating this phenomenon for the past decade through a series of cleverly designed experiments. Hama's research suggests that the availability of serotonin shifts the way we process emotional information at a subconscious level and this has a cumulative impact on how we feel. She sees depression as a case of this basic survival instinct gone awry.