ABSTRACT
Most adult mental illnesses begin in adolescence and early adulthood. They affect a young person’s ability to meet their full potential in terms of relationships, family functioning and educational and occupational attainment. One mental disorder may also predispose to another; for example, anxiety may lead to depression and/or substance abuse, so that individuals often exhibit a range of symptoms and difficulties. The other problem is that mental illnesses in young people, if left untreated, are likely to continue into adulthood and be associated with a range of poor outcomes. Clearly a focus on youth mental health is needed. Early intervention to prevent, or at the least delay, the onset of mental illness could minimise the associated damage to a young person’s social, educational and vocational functioning. The clinical staging model of mental illnesses provides a framework for this preventative approach. The model posits that mental disorders emerge in stages of varying severity and that over time symptoms may worsen and new clinical features may emerge. Individuals thus move through these stages, from mild to more severe presentations. The model suggests that if interventions are applied appropriately to each stage, then progression to more severe levels may be prevented. Interventions delivered during the early stages of an illness will be more effective and less harmful than treatments delivered later in the course of illness. Interventions can be evaluated in terms of their ability to prevent or delay progression to a later stage of illness. This chapter discusses the rationale for this approach.
