Deacon Jim Russell has an excellent essay on the subject.
He explains the difference between the Catholic understanding of same sex attraction/homosexual inclination as simply a temptation to sin, as opposed to the more Protestant understanding that the inclination itself is sinful. That's huge.
Here is the major distinction Catholics need to make between the Catholic understanding of reparative therapy and the understanding espoused by at least some Protestant Christian reparative therapy supporters: The competent and informed therapist will ground therapy in the understanding that the homosexual inclination itself is not an instance of personal sin but is a temptation to sin. As such, the Christian’s goal of therapy will be shifted—the goal will not be to completely eliminate the erroneously perceived personal “sin” of having the inclination, by stopping the inclinations altogether. Rather, it will be to move the person toward a less-difficult pursuit of chastity despite whatever may remain of the inclination itself after therapy.
If a therapist misunderstands the fundamental truth that the objectively disordered homosexual inclination is not a form of personal sin, someone can indeed be harmed by such therapies, even in a Christian setting. - Finish reading here.Deacon Russell also affirms the fact that reparative therapy may not be for everyone. That too is huge.
Simply stated, reparative therapy—grounded in a Catholic understanding of the human being—is one vitally important tool in the toolbox for anyone seeking both healing and chastity from the inside out. It is important to note that the Church doesn’t see reparative therapy as a form of healing that every same-sex-attracted person should or must choose. But the Church’s view of the human person clearly reveals the potentially great value of reparative therapy for those who may choose it. - Deacon Russell
Sometimes Catholics criticize Deacon Russell and other Permanent Deacons.
Before closing, I just want to say I cannot say enough good about the Permanent Diaconate in the Church. Deacon Russell and others are actually in Holy Orders. Those like Deacon Russell as well as others I have met, are solid, well formed, Roman Catholic ministers who work tirelessly for the Church. Usually married, with children, many have full time jobs and yet work in their dioceses, in chanceries, parishes or as chaplains elsewhere. They have the authority to teach. Which places them in the forefront of Evangelization. They are a great gift to the Church. Pray for them and support them, just as you do our priests.