An interesting article
on the first "ex-gay" study and it's methodology and outcomes by Warren Throckmorton:
A participant in the first study to use the term “ex-gay” to describe gay-to-straight change has called the study into question.
In 1980, E. Mansell Pattison and his wife Myrna Loy Pattison introduced the term “ex-gay” to the psychological literature via an article published in the American Journal of Psychiatry.* In that study, they claimed that 11 men participating in a crisis hotline at the Melodyland Christian Center, pastored by Ralph Wilkinson in Anaheim, CA, had changed dramatically from gay to straight.
But in an interview, Michael Bussee, who had been a leader at Melodyland at the time of the study, told me, “We professed that we had been healed—past tense—because it was part of the theology to claim your healing in order to bring it about.”
It not uncommon for people to claim a truth that they haven't reached yet, but it's the longer term results that are more interesting:
Along with several other ex-gay leaders, Bussee and his Melodyland colleague Gary Cooper helped found Exodus International, an evangelical ex-gay organization. However, they eventually came out of the closet, left their wives and became partners, thereby leaving ex-gay ministry in 1979. Cooper died in 1991 and Bussee has remained a critic of change efforts.