We constantly warn people about the dangers of illegal drugs and the damage they do to the Soul, that the illusions of pleasure they give are not worth their eventual cost.  Another good example of this are the reports coming from The Spirit Realm of Jerry Garcia, former member of the musical group The Grateful Dead.
The music radio stations in the Spirit Realm have been clamoring for an interview with Garcia and he finally agreed to let one of the more popular interviewers visit him at the Arab camp where he now lives.
The interview was a great disappointment to everyone, for Garcia explained that he was well aware he had been the person they were speaking of.  He had vague recollections of his childhood as this person up until the age of about eleven.  After that there is nothing at all...not a trace of any memory, no knowledge of any of the music he performed, or, the skills to now perform it.  He asked that people not bother him about this lifetime any more because there was nothing about it he could relate.
The interviewer expressed his regrets and left in great disappointment.  Garcia has permitted himself to be examined by some of the finest Healers in The Spirit Realm.  They have concluded that this loss of personality from this lifetime is permanent.  Not only that, but the loss of personality crept into several other lifetimes, besides, and destroyed personality in them, also.
This is a senseless and tragic loss.  This Soul has been set back drastically.  It will take it hundreds of years to repair the damage that has been done before it can continue to grow.
Illegal drugs effect no two Souls the same way, but the commonality is they damage, they destroy, they are not worth what they give.  The loss they cause is just too profound.