Neurobehavioral science in hazard identification and risk assessment of neurotoxic agents--what are the requirements for further development?

OBJECTIVES: Modern neurobehavioral methods find useful application in research into the early effects of exposure to neurotoxic agents in the environment. This paper briefly describes the history and evolution of neurobehavioral toxicology, reviews some current trends in research in this specific discipline and identifies the most important needs and challenges to be addressed in future studies. METHODS: All published literature was considered, including ad hoc meeting reports. Further information was obtained directly from experts in the field. RESULTS: The number of studies (including those in occupational, environmental and pediatric exposure) using neurobehavioral evaluation is constantly increasing. Regulatory agencies are using scientific data obtained through neurobehavioral assessment, which includes other areas such as neurosensory toxicology. However, further development of this discipline is facing a number of problems and issues. Three major areas that deserve further attention have been identified: (1) specific technical issues regarding testing development, (2) epidemiological issues regarding the study design, including the need for meta-analysis/multi-center studies and for longitudinal observation, and statistical issues regarding the most adequate models for the analysis and treatment of complex neurobehavioral datasets, and (3) the need for scientific consensus on the significance of adverse effects identified with neurobehavioral methods. CONCLUSIONS: The importance of neurobehavioral toxicology in the evaluation of mechanisms of action and for preventive purposes is progressively growing. Further development is needed for the advancement of this discipline through collaboration between experts from different fields.