Over 2-4 years, which tends to be the peak of sri related weight gain after which weight tends to plateau

didn’t just puff up like Violet in a chocolate factory

I’m sure you didn’t. I don’t doubt that the meds contributed somewhat, but there’s just no evidence that these agents can cause a weight gain of that magnitude on their own. Even the individual uncontrolled longitudinal studies that show the highest amounts of weight gain demonstrate at most 5-8kg increase.

There is no way that amount of weight gain was caused by an sri. Maybe you were on something else like an atypical/tricyclic antidepressant? Or maybe you were just depressed?

It’s true that differences between how individuals react to sris is pretty large and that <0.5kg number is a population wide average

Tbf the weight gain attributable to sris is tiny, like 0.5 kg over 6 months at most