In March 2014 Mark Zuckerberg dipped into his deep pockets to buy Oculus Rift for $2bn, proclaiming to the world that after many fits and starts, virtual reality would stick. Now Oculus Rift is on the verge of being launched to the masses, with a promise of greater immersion and more realism than ever before.

CG-rendered games will be the main driver, but growing evidence and use by clinicians suggests that VR could become a common tool for therapists. “The potential to treat phobias and fears is huge,” explains Chris Brewin, professor of clinical psychology at University College London. “In fact I’d put money on this becoming an important part of mental health treatment.”

Brewin speaks from experience. He and his team took 15 people being treated for depression by the NHS and strapped VR units around their heads. First they were shown an adult avatar, which replicated the patient’s body movements via haptic (touch) technology. This is a process known as “embodiment”.

VR therapy has helped smokers stop smoking and played a role in overcoming a fear of spiders

“That’s the key difference between this form of therapy and traditional therapy,” says Brewin. “When people are embodied in an avatar in a virtual world, their perception and emotional responses change to be consistent with that avatar.”

That’s why the 15 patients were then shown another avatar of a crying child, who was in a mirror, before being told to speak compassionate phrases to the child, to console and comfort. They then reversed the roles; in other words, the patient was embodied into the child’s avatar, with the adult avatar speaking back those same words of love and reassurance. This visible and audible compassion softened the patients’ self-critical traits, and nine of the 15 subjects reported reduced depression levels one month after the trial.

“If you embody someone in an avatar that represents a child, you find their perception changes to more of a child’s than an adult’s, almost taking themselves out of their adult mind and body,” says Brewin.

Though clinical use of VR is in its infancy in the UK, the US has been applying this technology for years, specifically to treat servicemen returning from Iraq and Afghanistan who are suffering from post-traumatic stress disorder.

Albert “Skip” Rizzo, director of medical virtual reality at the University of Southern California’s Institute for Creative Technologies, has worked with many soldiers, and explains how it works. “Traditional exposure therapy to treat PTSD relies on the person imagining the situation related to the trauma. But one of the key symptoms of PTSD is avoidance of the cues and reminders of the trauma. So it’s hard to expect someone to create a vivid mental image of something they’re trying to avoid.

“We place the person in VR simulations that the clinician can control in real time, and customise based on that person’s experience, but in a safe environment.” To do this, Rizzo and his team created 14 virtual worlds, varying from a large Middle Eastern city to remote outposts.

VR therapy has also successfully helped smokers stop smoking, and it can play a role in overcoming a fear of spiders. In an American study, 23 subjects were encouraged to gradually, and safely, approach a virtual spider. By the end, 83% of patients showed a significant improvement in how they dealt with spiders, with some so desensitised to the virtual spider that they could approach a real tarantula with minimal anxiety.

Where might this technology lead? “A VR unit and an app could be like buying a self-help book, but instead you’re purchasing a self-help VR scenario,” says Brewin. “That’s some way off, but it’s not unrealistic.”