Scientists studying electrical-brain stimulation to treat various conditions are raising medical and ethical concerns as people build their own devices to use at home.

People who have put together their own low-tech devices, using inexpensive components including 9-volt batteries, wires and electrodes, say they may boost creativity and cognitive performance. But scientists say most research supporting the technology involves patients with injured brains and may not apply to people with healthy brains in the general population.

Research has been under way for years to determine if noninvasive brain stimulation, including a form known as transcranial direct current stimulation, or tDCS, can help treat people with chronic pain, such as migraines, treatment-resistant depression or epilepsy. TDCS, which isn’t yet approved as a medical treatment by the Food and Drug Administration, is the technique most commonly adopted by makers of the home made devices. Delivering a constant, low current of electricity via electrodes on the scalp is believed to affect the likelihood of neurons firing in the brain.

Harvard Medical School’s Center for Bioethics recently convened two workshops where doctors, scientists and others discussed neurostimulation, including the trend of do-it-yourself brain hackers. The Institute of Medicine, a division of the nonprofit National Academies of Sciences, Engineering and Medicine, in July published a report online of the results of a workshop that examined ethical and medical issues involved with the growing popularity of neuromodulation devices. And the Food and Drug Administration is holding a two-day workshop related to the topic later this month, where scientists and laypeople are expected to discuss potential regulatory concerns as the technology takes off.

“You don’t often find a tool inside a lab that people replicate outside the lab and use their own way,” says Anna Wexler, who is studying the DIY brain stimulation community as part of a Ph.D. dissertation at Massachusetts Institute of Technology’s Department of Science, Technology and Society. “The controversy gets at the larger issue of who gets to control the tools of science,” says Ms. Wexler, who made a presentation at one of the Harvard workshops.