MDMA's therapeutic value is vastly underestimated, partly because though nearly all of the evidence is anecdotal due to it becoming illegal before its use in therapy was properly documented. Its properties allow it to be a suitable adjunct to all kinds of therapy--increased willingness to communicate, openness, empathy/love and forgiveness can be beneficial in couples or family therapy; diminished fear and anxiety, and acceptance make it extremely valuable in treating anxiety disorders (it was recently approved for a trial involving patients with Post Traumatic Stress Disorder--the study concluded in 2008 with promising results; a study involving anxiety in cancer patients is currently underway); increased pleasure and awareness, forgiveness of self or others, diminished insecurities and feelings of comfort and well being can help those who suffer from mood disorders.
Alexander Shulgin wrote in PIHKAL about MDMA's value as a therapeutic tool:
What does MDMA do that could be beneficial to a patient? First, it powerfully suppresses emotional fear, to such an extent that people under the influence are often able to openly discuss deeply traumatic events, such as rape, suicide attempts, etc. MDMA produces complete emotional honesty with yourself. Second, it is a moderately powerful stimulant, not simply allowing the patient to sit there indifferently, but prodding them to examine and discuss their lives. Animal experiments also indicate that MDMA enhances learning, allowing what is discovered and experienced during the MDMA state to strongly affect and stay with the patient long after the session.
The net result is a patient who, for a few hours, is almost perfectly primed to grow as a person. Their fears are gone. They feel strong, at peace, and able to handle almost anything emotionally. They're also hyperactive and extremely talkative, eager to explore ideas and issues and share their thoughts. The 'hyper-focused' MDMA state can also allow the therapist to steer the conversation into otherwise highly charged topics...they don't have to tease the story out of them; the patient is truly ready to talk about what's on their mind. And finally, the experience seems to allow a high degree of incorporation of what they learn about themselves back into their normal lives.
It is important to keep in mind that while for some, MDMA alone can be enough to allow the alleviation of depression or to stimulate the reconnection between a husband and a wife, in the context of clinical therapy it is not viewed as a panacea. MDMA, like any other drug, will not automatically allow someone to come to terms with a traumatic incident, it can only make it easier to do so. It can put the patient in a more receptive, forgiving, or happier state, but it is just as necessary that the patient desire to get better and that the therapist continue to do whatever necessary to help them achieve their goal.