There is good evidence that cognitive behaviour therapy (CBT) can improve the symptoms of anxiety. However, many people avoid or delay seeking treatment either because of stigma, because their condition limits how far they can travel or because of a shortage of qualified clinicians. Internet and computer-based treatments have been used in an attempt to overcome some of these barriers and researchers from Tacoma, Washington in the U.S. reviewed 19 trials into the effectiveness of Internet therapy for anxiety. They found that Internet therapy was more effective than being on a waiting list and as effective as traditional therapy. However, the trials had small sample sizes and some methodological problems so the review gave a qualified thumbs up rather than a whole-hearted endorsement.
Reger, Mark A. and Gahm, Gregory A. - A meta-analysis of the effects of Internet- and computer-based cognitive-behavioural treatments for anxiety Journal of Clinical Psychology January 2009, 65(1), 53-75