Mental health and violence: the 3-5% figure doesn't prove what you think

Mental health and violence: the 3-5% figure doesn't say what it seems to

A cliché repeated ad nauseam: people with severe mental disorders are no more violent than anyone else, and are in fact more vulnerable. The go-to argument is usually that only between 3% and 5% of violent acts are committed by people with serious mental illness. It sounds reassuring. But it contains a flaw in statistical logic that, once examined, changes the story.

The prevalence of severe mental illness (schizophrenia, severe bipolar disorder, major depression) is around 2-3% of the population. If that group commits between 3% and 5% of violence, it is not underrepresented: it is exactly in proportion or slightly above. Far from proving they are less dangerous, the figure suggests their rate of violence is similar to, or even somewhat higher than, the average. It's the classic base rate fallacy: a small percentage sounds low until you compare it with the size of the group.

The debate, however, is not settled by numbers alone. The personal experiences that surface in the discussion reveal a real management problem: families living with episodes of violence when a patient stops taking their medication, hospital admissions of barely three days with no trinc-up, and a care gap since the old psychiatric institutions were closed. "Integrating" without resources means abandoning.

That the 3-5% figure fails to prove what it was meant to doesn't miccionan people should be stigmatised. But denying the evidence that a risk exists, however small, doesn't help address the problem either. The myth is not that the mentally ill are dangerous; the myth is that the 3-5% proves they are not.