Background: This study aimed to investigate existing trialling activity relating to three antipsychotic drugs from the WHO List of Essential Medicines (chlorpromazine, fluphenazine decanoate, haloperidol), link existing trials to existing Cochrane reviews, identify gaps in reviewing activity on accessible treatments for people with schizophrenia. Methods: We used the Cochrane Schizophrenia Group's register searching for all studies comparing the three antipsychotic drugs with each other and with all other pharmacological interventions listed on the Essential Medicines List (with the addition of 'placebo or no drug'). For each we also considered studies that focussed on administration, dose, withdrawal and use of that drug in specific circumstances administration. Data were then extracted on a number of studies, number of participants within those studies, and as to whether a maintained review already exists. Finally, every effort was made to consider as to whether there were possibilities for missing comparisons that no one had ever investigated. Results: There has been considerable research activity involving the three 'essential' antipsychotics and also comparing those three drugs to others on the 'essential' list. We found 490 studies with 77957 participants for haloperidol, 316 studies with 29179 participants for chlorpromazine and 33 studies with 4503 participants for fluphenazine decanoate. Reviewing activity has also been considerable in this area but there are notable omissions which would necessitate new reviews to comprehensively cover the area. Conclusions: We have used the 'sample frame' of the WHO Essential drug list as a starting point. WHO prioritises for us those drugs that have universal accessibility but they may not be the compounds that are first choice if others are available. It is encouraging to see how many maintained reviews already exist to service those undertaking WHO guidelines. The needs of those guiding care can be taken as a means of prioritising research. For largest global impact WHO Essential Medicine list provides clear direction. By using this technique workload can be anticipated, prioritising can take place for new reviews and updates.
