Most research on ‘evidence-based’ interventions for alcohol and drug problems among young people as well as closely associated issues such as depression, anxiety disorders and offending behaviour, has focused on a small number of discrete treatment modalities particularly variations of cognitive behaviour therapy and family therapy. Reviews of this work indicate that these approaches are generally effective in improving outcomes within these problem domains, however they are less effective for young people with multiple and complex needs (ARCS (UK), 2008; Chassin, 2008; Muck et al., 2001; Toumbourou et al., 2007). Opinion and evidence is accumulating that for this population, a comprehensive or multisystemic approach is more effective than the use of singular treatments (Brannigan et al., 2004; Bruun, 2008; Chassin, 2008; Crome et al., 2000; Kidd, 2003; Muck et al., 2001; Slesnick, Kang, Bonomi, & Prestopnik, 2007; Spooner et al., 2001).
Writers vary in the breadth of their vision with respect to the number and range of dimensions or systems that should be included in multisystemic treatment. Involving families in the treatment of youth AOD problems is the one of the most widely endorsed aspects, but other systems or domains are also gaining regular recognition. Attending to concomitant mental health problems is one of these (Mark et al., 2006), as are issues of offending behaviour, homelessness, unemployment, and exclusion from school among others. Most adolescents with AOD problems requiring treatment tend to have a mix of one or more of these issues, but no one of these issues applies to every single adolescent with AOD problems. Hence these issues may be better understood in terms of the more inclusive and multilateral notion of ‘multiple and complex needs’ (Mitchell, 2011).
Complexity operates in at least two ways to reduce the effectiveness of single treatments and indicate the need for multidimensional approach. First epidemiological evidence shows that closely associated problems such as alcohol and drug use, offending behaviour, homelessness, and depression have multiple and interlinked determinants including biological, psychological and social factors operating at the levels of individuals, families, communities and whole societies (Spooner et al., 2001; Spooner & Hetherington, 2004). Second, these closely associated problems and determinants work to reduce young people’s ability to access and engage with treatment services (Chan, Godley, Godley, & Dennis, 2009; Crome et al., 2000; De Rosa et al., 1999; Meade & Slesnick, 2002; Rosenthal et al., 2008; Statham, 2004). Homelessness acts as a particularly pernicious barrier to treatment access in this regard. For homeless young people, a comprehensive approach to service provision may demand the provision of the basic necessities of life such as food, shelter and attention to physical ailments (Kidd, 2003).