I already mentioned this in another post elsewhere - theatment of phobias seems to be quite effective in VR. It's definitely not a case of VR being shoehorned to an existing solution but a whole new way of tackling the problem! :)

Fo example In VR doctor or patient can control the environment very finely for example move spiders remotely, select number of them if they jump or not etc. In real life you can visit insectarium but can't select the environment or control spiders behaviour. Also it's easier to persuade someone with phobia to put on a headset then to visit insectarium every weak or so ;)

Ever more interestingly VR can help with phobias that are simply are too complicated or cumbersome to be desensitised in real life. Take fear of flying planes - first you get used to seating in passengers seat, then you circle around for a bit, then maybe you lift off and immediately touch down afterwards. Who has money, space and time to organize something like this in RL? ; p In VR - Not a problem.

P.S VR can also cure lazy eye, people can see in 3d stereoscopy for the first time in their life after VR sessions :)