Background: Recently, patents of several atypical antipsychotics have reached their expiration date.
Aims: The purpose of the study was to highlight whether modifications of economic/scientific factors may be associated with possible changes in ongoing clinical research on antipsychotic drugs.
Methods: A large systematic analysis was used to depict the time-dependent distribution of published research articles addressing the clinical properties of oral risperidone and olanzapine conventional tablets, two largely prescribed atypical antipsychotics for which the patents have already expired in most of the countries.
Results: The systematic analysis indicated that the time-dependent distribution of the selected research articles followed a wave-shape pattern. A dramatic decline of primary and secondary analyses investigating the clinical effects of oral risperidone and olanzapine has occurred in the last decade, complemented by an expected strong reduction in the numbers of industrial-supported clinical studies and a smaller, but significant, decline in the amount of independent research articles.
Conclusions: To date, greater involvement of independent research seems to be the only realistic chance to properly continue the investigation on the clinical properties of oral risperidone and olanzapine conventional tablets, as well as those of other off-patent antipsychotic drugs. However, the limits and potentialities of independent research in accomplishing such a demanding and enduring scientific effort should be addressed.
Keywords: Antipsychotic; atypical; patent; systematic analysis.