From those in the know about mental health, it comes to no surprise that if you have any immediate family suffering with this then it is likely it has been passed down to you.
But for those with relapses in mental state and no immediate family with this. Then you are likely to have a Paranoia and it derived from one of your ancestors.
Many moons ago you would have been locked up in a mental asylum for being erratic in your notions. Just because people did not know or seen anyone with this
Thank god we can share our thoughts today with health care professionals and the like.
Talk to your family if you think you are under the influence of having a relapse.
.As they are likely to understand what you are going through.