Scott Alexander defends psychiatry's use of 'chemical imbalance' theory, arguing it was meant to emphasize depression's biological basis rather than claiming a simple serotonin deficiency. Longer summary

Scott Alexander responds to criticisms of psychiatry's use of the 'chemical imbalance' theory of depression. He argues that psychiatrists never claimed depression was simply a serotonin deficiency, but rather a complex interaction of brain chemicals. He explains that the term 'chemical imbalance' was used to emphasize depression's biological basis and help people take it seriously, rather than viewing it as a personal failure. Scott provides evidence that serotonin and other neurotransmitters are indeed involved in depression, while acknowledging the full picture is more complicated. He concludes that framing depression in terms of brain chemistry remains useful, even if 'chemical imbalance' is no longer the best terminology. Shorter summary