In many places around the world, there are people connecting electrodes to their heads to electrically stimulate their brains. Their intentions are often to boost various aspect of mental performance for skill development, gaming or just to see what happens. With the emergence of a more accessible market for glossy, well-branded brain stimulation devices it is likely that more and more people will consider trying them out.

Transcranial direct current stimulation (tDCS) is a brain stimulation technique which involves passing a small electrical current between two or more electrodes positioned on the left and right side of the scalp. The current excites the neurons, increasing their spontaneous activity. Although the first whole-unit devices are being marketed primarily for gamers, there is a well-established DIY tDCS community, members of which have been using the principles of tDCS to experiment with home-built devices which they use for purposes ranging from self-treatment of depression to improvement of memory, alertness, motor skills and reaction times.

Until now, non-clinical tDCS has been the preserve of those willing to invest time and nerve into researching which components to buy, how to attach wires to batteries and electrodes to wires, and how best to avoid burnt scalps, headaches, visual disturbances and even passing out. The tDCS Reddit forum currently has 3,763 subscribed readers who swap stories about best techniques, bad experiences and apparent successes. Many seem to be relying on other posters to answer technical questions and to seek reassurance about which side effects are ‘normal’. Worryingly, the answers they receive are often conflicting.

One DIY-er posted about his experience as follows:

So I hacked together a real quick tDCS device with little more than 1.8 miliamp current regulating diode, a 9 volt battery, a single metal annode and two metal cathodes. Most basic circuit possible, I guess. Whoa though, does it ever burn. Any thoughts as to why? Is this simply me being a puss or something?

Also concerned about side effects, another asked:

I used tDCS for a week, 10 to 20 minutes per day at 1.0mA and found that I seemed to be getting angry frequently. Has anyone noted any emotional impact to tDCS therapy?

Some posters seek basic advice on the configuration of a device:

I have a 9 volt tdcs unit with red cables going to the positive terminal, and black cables leading to the negative. I am trying to increase my working memory via anodal stimulation to my DLPFC and cathodal stimulation to my left supraorbital region. I am having an extremely difficult time figuring out which electrode is the anode/cathode. […] What is the your final answer to my problem?

Positive experiences of experimentation are also reported:

During the session I noticed a high increase in mental acuity, an enhanced ability to think outside the box, and an increase in logic/reasoning skills (which is quite something for me, since I usually throw logic out the window).

People will always be able to build their own devices and it is likely that the interest in tDCS will continue to grow. However, many of the reported pitfalls and the need for trial and error could be avoided if specially manufactured whole-unit devices met the same standards and specifications of the tDCS devices used by research scientists. Dr Roi Cohen Kadosh, who has run numerous lab experiments using tDCS says:

As much as I am enthusiastic about research with tDCS and the current results from my lab and others, it is still early days and the results that people read about are produced in controlled lab environments, using participants who have gone through screening. Researchers adhere to strict safety regulations pertaining to the amount of electricity delivered in a specific time, the size of electrodes, and the maximum time that it can be used. It is also administered by a trained scientist. In addition, one needs to know which brain area to stimulate and what type of training to provide to reap the fruits from tDCS. tDCS alone will not improve peoples’ performance. I therefore think that the current generations of stimulators are not situated to provide enhancement in human performance.

Although a move from home-constructed devices to specially manufactured devices has the potential to offer a safer option for those keen to experiment, Dr Thomas Douglas notes that “currently there’s a crazy situation where brain stimulators sold for improving normal function are regulated much less stringently than the same or similar devices sold to treat diseases.” Yet, as explained above, electrode size, position and polarity, and the strength and duration of the stimulation are amongst the things that must be within certain parameters for a device to be used safely. The lack of regulation of devices marketed for enhancement means that none of this is ensured.

My colleagues and I have just published a policy paper making a number of recommendations which we believe would make the consumer market for cognitive enhancement devices (CEDs) safer for everyone. We suggest that they are regulated in the same way as medical devices, providing consumers with the assurance that a particular device meets certain standards of safety and (to a certain extent) effectiveness. Most importantly, it will also ensure that sufficient information about correct use and potential risks is provided with the device so that consumers can make informed choices and can use the device in the safest possible way.

Our recommendations are not at all motivated by a belief that access to cognitive enhancement devices should be restricted in general but, rather, that consumer freedom is enhanced when what they buy is in fact what they think they are buying and when they have the information they need to assess what risks they are willing to take in pursuit of which potential benefits.

Reiterating this sentiment, Prof Julian Savulescu says:

CEDs are the tip of the enhancement iceberg: cheap, easily replicated, widely accessible technologies to enhance human performance. It is important we don’t fall prey to fear, scare mongering and excessive aversion to loss, and so over-regulate. Freedom is as important as ever. But freedom without knowledge is useless or worse, dangerous. An important balance needs to be struck between protection of public safety, providing accurate information and allowing people to live their lives as they choose, including taking reasonable risks.

As someone with a personal interest in the effects of tDCS, I would welcome a regulatory system that enabled me to choose to use devices in a transparent and informed way. It may be that some of the devices now on offer would already meet the standards we suggest, but this is certainly not guaranteed. I have, in fact just taken delivery of one of the devices currently causing a stir (see picture!), and I intend to try it. But I’m lucky: I have the opportunity to try tDCS in the knowledge that my colleague can test the device and show me how to use it. He will be able to show me how to use it safely and how to achieve the best effects. It would be good news for consumers if they too could be better protected from the burnt scalps, crossed wires and unnecessary side effects endured by the Reddit posters. Adopting the regulatory model we propose would go a long way to giving them the freedom to pursue enhancement in the safest way possible.

To read the policy paper, please click here.