What is Minimally Adequate Treatment of Psychosis and Should Duration of Inadequate Treatment (DIT) be a Clinical and Research Target?:A Perspective and State-of-the-Art Review

Background and Hypothesis Persistent symptoms and disability are common in psychotic disorders. This may be partly attributable to inadequate antipsychotic treatment, but there has not been a recent overview of what constitutes inadequate treatment and its impact on outcomes. Study Design We focus on the latest meta-analyses to critically appraise the relationship between markers of inadequate antipsychotic treatment and outcomes from the first episode of psychosis onwards, relating outcomes to periods without antipsychotic use, antipsychotic treatment of subtherapeutic dose/duration, and antipsychotic partial/non-adherence. Study Results Inadequate antipsychotic treatment is common (non-adherence rates=44-56%), and repeatedly associated with poorer outcomes across several key patient-centred outcomes, including increased risk of relapse (relative risk (RR) up to 2.70, n=13,988), more severe overall symptoms (standardised mean difference (SMD) up to 0.78, n=8,878), poorer quality-of-life (SMD up to 0.50, n=1,421), poorer functioning (SMD up to 0.55, n=1,988) and higher mortality (RR up to 1.83, n=272,030). We also find there is more evidence for schizophrenia than other psychotic disorders. Conclusions We identify that there are no operationalised criteria for the minimally adequate treatment of psychosis, in contrast to major depression, for example. We propose that a longer duration of inadequate treatment (DIT) may be an important predictor of outcome, although this has not been tested. To address this and support the development of interventions to reduce inadequate treatment, we propose operationalised criteria for the minimally adequate treatment of psychosis and the DIT, proposing both clinically applicable and research criteria. Finally, we consider future directions for research and practice.