Background: Presentation to substance misuse treatment is believed to coincide with extremes of behaviour or function, leading some to suggest that such extreme behaviours can improve over time, in the absence of appropriate, evidence-based treatment. In challenging times for services, it is essential that available evidence on this potential explanation of the treatment effect is summarised and disseminated to policy makers. We combined an analysis of existing data with a rapid literature review.
Methods: We used the UK Drug Treatment Outcomes Research Study (DTORS) baseline cohort (N = 1,794) to examine levels of substance use and offending at treatment presentation, in relation to self-defined norms. A rapid review identified 7 studies (US, 5; UK, 2) examining change in substance use, and 6 studies (Australia, 1; Norway, 3; US, 2) examining change in function, ahead of treatment.
Results: In our sample, users were unlikely (9%) to be using more drugs than self-defined norms at treatment entry, and more likely (39%) to be using less than self-defined norms. A minority (24%) offended at higher levels than self-defined norms; 43% at lower levels. Among studies in the review, none identified increased substance use; 3 identified reduced function (employment, court appearances, and mental health admissions).
Conclusion: Available evidence fails to support the belief that presentation to treatment commonly occurs at extreme points of behaviour. An increase in substance use ahead of treatment was not evident; data on reduced function was ambiguous.