They DO know the rate of psychotic breaks in the general population. They kinda need that number to determine the increased risk of drug users.
LOL, yes of course. But as far as I saw it wasn’t in the summary. Lancet is a medical journal so I imagine the data is in a chart there somewhere. My point was, we laypeople don’t know the number. So reporting a 400% increase in risk is a sort of propaganda by omission. If the rate is 1 in 1 million, a 400% increased risk is statistical noise. I don’t think the rate is that low, but you catch my drift.
And then there are all the other variables than need to be controlled. Potheads probably also have a number of other similarities. I read about how many of the post hoc studies showing that eating too much red meat increases risk of heart disease. Researchers many years later realized these studies didn’t control for sugar intake. Maybe red meat eaters also tend to have more dessert after dinner and/or sugars in their bread and coffee etc? Without the right controls any study can be incredibly misleading.