therapy by phone

The New York Times Well blog posted an interesting article about a new study on the benefits of therapy by phone, published by Clinical Psychology: Science and Practice. The phone offers a means for physicians to reach out to patients who can't or won't make it in for face-to-face visits.

You can find the article here: http://well.blogs.nytimes.com/2008/09/22/the-benefits-of-therapy-by-phone/.

Let's consider this from a communication perspective. What aspects of communication might be lost in therapy by phone rather than in person? Could there be benefits of phone conversations over in-person conversation?