Genetic repair?

Scientists are also developing techniques to treat and cure genetic diseases through genetic surgery and genetic therapy. They can already identify genetic sequences that are defective, and soon scientists will be able to replace these defects with properly functioning genes. I copied and pasted that from a website. I read that OCD is showing more and more signs of being biological and therefore genetic in nature, another website said all disease or defective behavior has some genetic element of change. From what I copied and pasted it sounds like they can identify these defective sequences and replace them with properly functioning genes, does this mean virtually a cure for all disease or deviant behavior? I suffer from OCD, so this information is very exciting to me, even if its not possible for a very long time, its still something to hope for.

Just because defective genetic sequences are associated statistically with some diseases or conditions does not mean they are causally linked, or linked in any way, and replacing genes in a developed human body cell will not make much difference. This is particularly true where gene expression during fetal development leads to subtle changes in the brain that cause certain diseases or conditions (like OCD). You would have to regrow the whole brain, resulting in a different person.

If they can establish that the difference results in a protein or amino acid problem, and you can inject cells that have been programmed to correct that problem, then you can treat the problem in adults. The most recent example of this (though in reverse) is the discovery that addictions go away when a small part of the old brain is damaged. If the damage means that part of the brain no longer processes a chemical signal the correct way, it may be possible to administer a drug that inhibits the same chemical signal, making it possible to control addiction completely. Amazing!