“…We considered several individual, peer and family factors. When searching for relevant literature on illicit drugs we focused on cannabis, as in Finland, like in many developed countries, cannabis products (marijuana, hashish) are the most commonly used ones (Programme on Substance Abuse, 1997; Virtanen and Sjöberg, 2006 (Guxens et al, 2007a(Guxens et al, , 2007bKandel and Yamaguchi, 1993), especially age of onset (Gilvarry, 2000;Vega and Gil, 2005), alcohol consumption (Guxens et al, 2007a(Guxens et al, , 2007b, especially drinking to intoxication Wittchen et al, 2007). Own ever smoking was asked prospectively at the age 14 survey.…”