“…Of the six studies that assessed proxy measures of potentially addictive behaviors [42,[82][83][84][85][86][87] (Table 2), two studies [84,99] examined general adult populations (e.g., national surveys) using proxy indictors of problematic use, two [85,86] considered both adolescents and adults, while the latter two [82,87] examined adolescent populations (e.g., secondary school students). A total of five of six studies [82-84, 86, 87] using proxy measures investigated alcohol use and substance use, while four considered smoking cigarettes [82,84,86,87], and one investigated gambling [85]. The geographical locations also varied with papers based in the USA (n = 2) [83,87], Italy (n = 1) [82], Canada (n = 1) [84], the Czech Republic (n = 1) [86], and France (n = 1) [85].…”