This is, actually, an under-researched area, but here’s a start:
The top three results for why people tried to change their sexual orientation included “To be a better Christian,” “I believed it was what God wanted me to do,” and “I feared I would be condemned by God.” After that comes such responses as a general desire to fit in, cultural pressures to conform, and a desire to please family and friends. But beyond the numbers lie the written responses of survey participants which illustrates the huge variety of their experiences
Question 8 asked why they quit the ex-gay movement. The top answer, by far, was that they failed to become straight. But one disturbing answer given by nearly a quarter of respondents was that they had had a nervous breakdown.
Only a relatively small minority of this particular sample, less than ten percent, say they weren’t harmed by their participation in the ex-gay movement.