I'ves of taken over 100 LSD " mico -dots" all between the age 14-17 over 20 years ago. I have never experienced any sorta of "flash back" or any other ill effects . I think every person is different when it comes to taking psychedelics. I believe every individual has their own "chemical balance". I have know of one person who took LSD one time and never was the same. He started walking backwards.... For years he walked around our small town in reverse. He became know as backwards man. True story.