Antipsychotic interventions in prodromal psychosis: safety issues.

In recent years, psychopharmacological intervention in prodromal psychosis, also known as the ultra-high risk (UHR) mental state for psychosis, has attracted much attention. Whilst it has been shown that antipsychotic use in UHR individuals may be effective in potentially delaying or even averting progression to frank psychosis, their use in subjects that do not necessarily convert to psychosis has raised considerable ethical concerns because of their adverse effects. Recent treatment guidelines for patients at UHR for psychosis recommend the use of antipsychotics only in exceptional conditions and with great precautions. To date only a few studies have investigated the use of antipsychotic medications in UHR patients and the potential benefits and risks related to their use in prodromal psychosis remain unclear. We review here all published studies that included UHR patients treated with antipsychotics, regardless of study design. These studies were all of second-generation antipsychotics, given that first-generation antipsychotics cannot be recommended because of their adverse drug reactions. We specifically examine the available descriptions of adverse reactions of the individual antipsychotic medication in each study and discuss the potential effects of various demographic and clinical factors that may impact on safety issues of pharmacological interventions in UHR patients. Clinical trials to date investigating potential benefits of antipsychotic treatments in preventing transition to psychosis were of relatively short duration and have involved a small number of patients. Whilst it appears that pharmacological intervention at this stage may be effective in both reducing the psychopathology and decreasing transition rates, and is potentially safe, in the absence of sufficient evidence-based knowledge to guide treatment, definitive clinical recommendations and guidelines cannot be derived. Certain adverse events take time to develop, such as metabolic syndrome and endocrine-related effects, thus longer term clinical trials with a larger number of patients are needed to determine the effectiveness of antipsychotic intervention and the relationship of its duration to emergence of adverse events. This can inform the development of timely strategies to prevent serious negative impacts and thus maximize the benefits of antipsychotic intervention in UHR patients that outweigh the risks associated with their use.