Since the 1960s, researchers have postulated that major depression stems from disruptions in the serotonin neurotransmitter system, but the evidence for that idea, though plentiful, was indirect. In fact, a recent comprehensive analysis of existing studies concluded that there was not strong evidence to support the “serotonin hypothesis.” In its wake, some in the field have called for a reexamination of the hypothesis. Not so fast, says a new study that provides direct evidence of disrupted serotonin release in the brains of individuals with depression.
