Depot antipsychotic preparations in schizophrenia: the state of the economic evidence

Depot treatment of schizophrenia - to date restricted to conventional antipsychotic medications - remains widespread. Whilst there have been numerous studies of clinical effectiveness, and systematic reviews of the accumulated evidence, little appears to be known about the cost-effectiveness of depot treatment. A systematic review was conducted of the international literature in an attempt to find, appraise and summarize the economic evaluative evidence. Very few studies of relevance or quality could be found. Most of the papers purporting to examine the economic consequences of depot treatment were methodologically weak. There were no randomized controlled trials of depot vs. oral antipsychotics, the few mirror-image studies were uncontrolled and a single naturalistic observational study measured costs only narrowly. Two modelling studies - which have a number of limitations because of their partial reliance on expert opinion rather than observational data - suggest that depot treatment may lower costs and improve cost-effectiveness. Overall, however, it is not possible to draw conclusions as to the cost-effectiveness of depot conventional antipsychotic treatment for schizophrenia.