To get a psychological disorder does not mean a distant relative was a looney. Genetic makeup is a huge factor in getting a disorder but not the only factor to cause it. Brain damage or trauma can trigger a disorder. Epilepsy and brain convulsions along with strep infections can trigger permanent OCD. Sociopaths usually become that way when they are shown no love by their parents. Hence they grow up unable to feel emotions normally. If a childs parents never loved them then why should a stranger. But usually there seems to be an underlying factor that makes a child more prone to sociopathy and when raised in the right (or wrong I should say) they become cold and calculated feeling no emotion.
Can psychological disorders be prevented? In some cases maybe. But how is a parent to accept the fact that they are the cause of triggering sociopathy in their children. How do you prevent a person from getting an epileptic seizure? Even though we know some causes to disorders this doesnt meaan we can prevent them or cure them. We can better understand them and hope this helps with future treatment or possible prevention but thats about all we could do. Once the brain is damaged theres no reversing it. But future advances could lay the foundation for more cures.
I had high fever convulsions when I was a child which led to my getting OCD. In brazil in the early 1990s they had a major epidemic of strep throat. tens of thousands of kids got strep throat and afterward it was noticed that over 5 percent of those affected with strep throat became permanently ill with Torrettes and OCD.