“…Client characteristics include age (Deck & Carlson, 2005;Friedmann et al, 2001;Hser et al, 2004), poly substance use (Hiltunen & Eklund, 2002;Sorensen et al, 1985), treatment motivation (Joe et al, 1999;Longshore & Teruya, 2006), and client's psychological function (Grella & Wugalter, 1997;Joe et al, 1999). Social characteristics include family support (Dobkin et al, 2002;Siddal & Conway, 1988), community support (Brown et al, 2004), and peer support (Booth et al, 2004). Some studies found that interactions between these factors were also significant in predicting treatment success (Ball and Ross, 1991;Chou, Hser, & Anglin, 1998;Hser et al, 2001).…”