Exposure therapy asks a person to approach what they fear, gradually and with support, until the fear loses its hold. Virtual reality exposure therapy (VRET) does the same thing inside a headset. A meta-analysis in the Journal of Anxiety Disorders pooled the randomised controlled trials to see how well it works.
The review covered 30 studies with 1057 participants. Fourteen tested VRET for specific phobias, eight for social anxiety disorder or performance anxiety, five for post-traumatic stress disorder and three for panic disorder.
Effect sizes are reported as g, where a larger number means a bigger benefit. VRET compared with a waitlist produced a large effect (g = 0.90), and compared with a psychological placebo a medium to large one (g = 0.78). Compared with in vivo exposure, which means exposure in real life, the difference was not significant (g = -0.07). The results were relatively consistent across the disorders.
There was one caution. Larger studies tended to report smaller effects.
The authors concluded that VRET is an effective and equal medium for exposure therapy. For people who find real-life exposure hard to arrange or hard to begin, that is encouraging. If fear or anxiety is limiting your life, a psychologist or your GP can help you find a suitable treatment.
What the review set out to do
Virtual reality exposure therapy (VRET) delivers exposure to feared situations through a headset. The authors had published an earlier meta-analysis that examined 13 trials, most of them on specific phobias. Since then, trials of VRET have proliferated in number and diversity, and they now include social anxiety disorder (SAD), posttraumatic stress disorder (PTSD) and panic disorder (PD), with and without agoraphobia. The authors considered it imperative to re-examine how well VRET works for anxiety-related conditions.
How it was done
The team searched for randomised controlled trials that compared VRET with a control condition or with in vivo exposure, meaning exposure to the real situation. They found 30 studies with 1057 participants. Fourteen studies tested VRET for specific phobias, eight for SAD or performance anxiety, five for PTSD and three for PD.
Results were combined using a random effects analysis. The effect size reported is g, a standard way of expressing how large a difference between groups is, with larger numbers indicating a bigger effect.
The comparison groups are worth understanding. A waitlist comparison asks whether treatment does better than simply waiting. A psychological placebo condition is a more demanding test, because participants receive attention and a plausible activity without the active ingredient of exposure. Effect sizes are conventionally described as small, medium or large, which is why the authors label the first result large and the second medium to large. Showing a benefit over a placebo condition is generally harder than showing one over a waitlist.
What it found
VRET showed a large effect against waitlist (g = 0.90) and a medium to large effect against psychological placebo conditions (g = 0.78). The comparison that most readers will care about is VRET against in vivo exposure. Here the effect sizes were not significantly different (g = -0.07), which means that, on average, the two delivered similar benefit. These findings were relatively consistent across disorders.
A meta-regression looked at whether study size made a difference. Larger sample sizes were associated with lower effect sizes in the VRET versus control comparisons (beta = -0.007, p < 0.05). In plain terms, the bigger the trial, the smaller the advantage it tended to find.
What it means, and what to keep in mind
The authors concluded that VRET is an effective and equal medium for exposure therapy. That matters because real-life exposure can be hard to arrange. A person with a fear of flying cannot practise on demand, and some situations are difficult to repeat or to control. A headset can make graded, repeated practice possible in a therapy room.
The finding about study size is a reason to read the headline figures with care. Smaller trials can overstate benefit, so the large effect against waitlist is probably best understood as the upper end of what to expect. The comparison with in vivo exposure is the more reassuring result, because it suggests that choosing VR does not cost people the benefit of exposure.
If fear or anxiety is limiting your life, speak with your GP or a psychologist about which approach suits you.