Right, you need a mechanism. (Ice cream makes you fat, fat people can't swim, ergo drownings). Haight clearly outlines the mechanisms by which social media and smartphones have detrimental effects on mental health, see: https://www.youtube.com/watch?v=-l2TdinWoM8
And if you swim enough, you can't get fat no matter how much ice cream you eat. Ever seen the diet Phelps was on? Guy ate like crap, has over 20 gold medals to his name.