The NIH has amended its definition of clinical trials to include brain studies, introducing new regulations considered unnecessary by many researchers.

The National Institutes of Health (NIH) has implemented its controversial decision to broaden the scope of clinical trials to include cognitive and behavioural studies. This change, which has been in discussion since at least 2014, is defended in part by the NIH because brain studies evaluate health-related outcomes. Although the change was officially announced three years ago, it wasn’t put into effect until this summer, according to an article reported in Science.

Cognitive and behavioural studies falling under this new definition will be under the more stringent regulatory requirements usually reserved for pharmaceutical research, even if they don’t test new treatments. Some of these requirements, such as training and registration on federal trial websites, are considered an unnecessary burden by many American-based neuroscience researchers.

There is still much uncertainty regarding which type of studies will fall under the new definition. To clear up any misconceptions, the NIH released a set of case studies in August. These examples confirmed that simple imaging studies of normal brain function are now considered clinical trials under the agency’s new policy. However, the case studies were also criticized as being inconsistent, further fueling the controversy. For example, a study of learning in children was not considered to be connected to health and thus is not a clinical trial while a memory study in adults is considered a clinical trial.

The Association of American Medical Colleges and several prominent researchers have criticized the agency for not being clear enough with the implementation of this new policy. The NIH is continuing to receive feedback on the change and hopes to update the case studies soon to minimize confusion.