Vitamins, snake oil, and a flawed review: A commentary on Folk and Dunn’s systematic review on 5 behavior strategies to improve ‘happiness’

A recent unregistered review by Folk and Dunn1 sought to determine the effectiveness of commonly prescribed “happiness” enhancement strategies. In this opinion piece, we argue that Folk and Dunn’s conclusions are misleading, with the potential for serious public harm. We believe this to be true when considering five major limitations inherent to the systematic review strategy employed by Folk and Dunn, namely the: (i) conceptualization of “happiness”; (ii) search terms used; (iii) inclusion criteria; (iv) adherence to established systematic review protocol; and ultimately, (v) their interpretation.