I believe that the best way to understand what you call mind problem is the adpatibility of the brain. We know that sinning would darken the heart and cause people to no more consider sinning as evil. A similar slow change could perhaps occur also in our bodies to sinning. This popped into my head when I watched this news about certain experiments on robotic hands for amputees. The intresting aspect of the expermient was that the brain slowly wires by itself to this robotic hand and feels like his real hand. I also remember reading studies about phantom hands which is a similar problem where the mind thinks it still has a hand despite the hands being amputed. They learnt to cure it by using a mirror to change the impression the brain signals receive and thereby to "rewire" it. The point important here is the adaptibility of the brain. Their atmosphere,lifestyle, influences, thoughts, emo culture etc could slowly rewire the brain towards gayness. And hence it is fully possible that they have a genuine mind problem in their homosexuality. This ofcourse is irrelevent to the Islamic legislation against homlsexuality but helps us understand how they reach their state. The other option of the mind problem is that they are simply shameless that they would do whatever, in the way of the famous saying of the past "if you do not have shame then do what you like".