Long DUP is clearly associated with poor outcome, independent of the confounders so far explored. Early intervention of specialist services in first-episode psychosis does improve outcomes in the short to medium term. Prodromal services, although potentially very exciting and innovative in creating avenues for treating people who seek help and are at high risk of developing a serious mental illness, are not focused on reducing DUP but on preventing transition to psychosis. Given that we are not able to change prognostic factors such as gender, family history and age at onset, DUP is a malleable variable which should and perhaps can be reduced. However, two caveats remain. First, to make studies comparable a consensus, reliable and replicable measure of DUP should be used across studies to reduce the variation introduced by the measurement process; DUP is a complex enough construct anyway. Second, DUP is not a valid measure for establishing the effectiveness of early intervention services that aim solely to provide evidence-based care in an assertive manner without an early detection arm. Most early intervention services do not conduct early detection, and their effectiveness and rationale should be judged on different criteria: those of meeting a clinical need early, comprehensively and with the best possible available combination of psychosocial and biomedical interventions, rather than simply the reduction of DUP.