When we notice a change in the world, or in a lab, scientists wonder what caused the change. But how do we figure that out? It seems like a simple question, but there are numerous pitfalls along the ...

When we notice a change in the world, or in a lab, scientists wonder what caused the change. But how do we figure that out? It seems like a simple question, but there are numerous pitfalls along the ...

You report that people with a severe covid-19 infection are more likely to be diagnosed with schizophrenia, suggesting that covid-19 heightens the risk of this condition (13 January, p 16).