“…Similar findings have been found on the relationship of age of onset of use of other drugs on the risk of adult drug dependence (Dennis, Babor et al, 2002). In addition to increasing the risk of developing a substance use disorder, early age of onset of regular AOD use is associated with rapid problem development (Kreichbaun & Zering, 2000), greater problem severity and complexity (e.g., psychiatric comorbidity) (National Institute on Alcohol Abuse and Alcoholism, 2003;Arria, Dohey, Mezzich, Bukstein, & Van Thiel, 1995), less social support for subsequent recovery (Sobell, Sobell, Cunningham, & Agrawal, 1998), and poorer treatment outcomes as measured by rates of post-intervention relapse (Keller et al, 1992;Kessler et al, 2001;Chen & Millar, 1998). More studies are needed to confirm this relationship between lowered age of onset and reduced prognosis for long-term recovery and to identify the precise mechanisms that compromise these recovery outcomes (Chou & Pickering, 1992).…”