The first large-scale preliminary clinical trial of energy psychology [EFT] is reported in some detail in Energy Psychology Interactive and summarized here. You can read the full version on the national EFT web site.

Approximately 5,000 patients diagnosed at intake with an anxiety disorder were randomly assigned to an experimental group (EFT) or a control group (Cognitive Behavior Therapy (CBT) with medication, which is traditionally considered the therapy of choice).  Here are the results:

Outcome Comparisons with 5,000 Anxiety Patients at Close of Therapy

At one-year follow-up, the patients receiving EFT treatments were less prone to relapse or partial relapse than those receiving CBT/medication, as indicated by the independent raters assessments and corroborated by brain imaging and neurotransmitter profiles.

Please note: EFT was not only significantly more effective, it also needed far fewer sessions (5 times faster).

My personal success rate is over 97% getting significant relief, and I find EFT to typically be 10 to 20 times faster than other methods.