Digital therapeutics for mental health are devices and apps that measure or treat stress and anxiety between visits to a therapist. Two kinds are common. One is a headband that reads the brain's electrical signals and trains the user to relax. The other uses virtual reality (VR), a headset that shows a 3D scene all around the user, for therapy sessions.
Anxiety is often a chronic condition. It can last for years, and it needs practice every day, not only one session a week. A therapist, such as a trained counsellor or a psychologist, may see a client once a week, often through online therapy. What the client does between sessions matters as much.
The headband works through EEG, electroencephalography. Small sensors on the forehead pick up the tiny electrical signals of the brain, measured in millionths of a volt. Software on the phone turns these signals into a measure of how calm or stressed the user is. For instance, a 20-year-old college student in Chandigarh has panic attacks before exams. Each evening, she wears the headband for 10 minutes and does a breathing exercise. The app plays a soft sound that gets quieter as her brain signals show that she is calming down. This is called neurofeedback: the user hears or sees a live measure of their own brain activity, and learns to change it. Her therapist sees a weekly chart of her scores. The headband is one kind of non-invasive brain-computer interface (BCI).
VR is used for exposure therapy. In exposure therapy, a person faces what they fear step by step, in a safe place, until the fear becomes weaker. Consider a man who is afraid of speaking in meetings. At the clinic, he puts on a VR headset and stands in front of a virtual audience. The therapist starts with five quiet listeners. Over later sessions, the therapist adds a larger and noisier room. The therapist controls each step from a tablet and can stop the scene at once.
These tools support therapy; they do not replace the therapist. A tool that claims to treat a condition must show evidence for that claim. It may then be regulated as software as a medical device (SaMD).