Transcranial direct-current stimulation – don’t try it at home

“Many Shubs and Zulls knew what it was to be roasted in the depths of the Sloar that day I can tell you.”

I’ve written before about tDCS and in particular the device produced by a company called foc.us; a company marketing a tDCS device to gamers. As a brief recap, tDCS involves passing a low-level electric current through your brain, and thereby attempting to stimulate particular regions of the cortex in order to enhance particular functions. Academics have been using this (and similar) method for a while now, and showing some interesting effects in all kinds of motor, sensory and cognitive domains (for a fairly broad review see here; PDF).

When academics perform this procedure on their experimental subjects for the purposes of research they have to get clearance from an ethical review board first, and they observe strict limits in order to ensure the safety of their participants, both in terms of the time they stimulate for, and the amount of electrical current they use. However, there is a community of amateur tDCS enthusiasts, who build their own equipment and zap their brains at home. If this sounds like a spectacularly bad idea, you’d be dead right. These guys (and let’s face it, it’s usually guys) naturally aren’t bound by the same safety rules; the only limit is their own stupidity.

TDCS appears to be becoming more mainstream, with commercial products like the foc.us headset and positive write-ups in media outlets (like this one and this one) helping to raise the profile of what has been up until now, a pretty niche activity. This BBC report focuses on the military applications of the technology and proclaims that the US military are ‘very interested in its potential’. Yeah, well… the US military also ran a 20-year research program into remote viewing and other psychic phenomena (only discontinued in 1995!) so let’s not put too much faith in their ability to spot obvious bollocks.

The point I want to get across here is that DIY-tDCS is not only pretty unlikely to actually do anything useful, but can also be potentially extremely dangerous. I know, right? Who’d have thought that passing electric currents through your brain might be a problem? The tDCS sub-reddit page is full of horror-stories ranging from people suffering electrode burns (like this guy) to this story of a user suffering crippling anxiety, panic attacks and depression for more than a year after tDCS. Whether the tDCS actually caused these fairly extreme symptoms in this particular case is somewhat debatable, and probably unknowable, but the point is that relatively severe adverse events can, and do happen with these devices. Most worryingly of all, there’s a report here on the electrical safety of the commercial foc.us device, which suggests that it doesn’t perform in the manner it specifies in terms of regulating the voltage, and can cause skin burns. This user claims to have suffered severe migraine-like pain after a session with the foc.us device.

To sum up:

Do not pass electrical currents through your head! It is a bloody stupid thing to do.

Seriously, if you want to give yourself some kind of an ‘edge’ in gaming, or studying, or whatever, just have a quadruple espresso – much safer and more effective.

Thanks to @neuroconscience for pointing out the tDCS horror-stories on Reddit.