Humans in the grip of mental illness have long been known to entertain the sane with their delusions or paranoia, but often those whose shackles to the rigid norms of what social propriety will allow tell the truth where others more sane remain in denial. Pointing the finger of an insanity accusation is one of the most effective ways to discredit someone, and thus those who have a history of mental illness are allowed to speak their mind and are not considered a threat by the establishment. Thus, mentally ill contactees were never harassed by MJ12 or the establishment, and even if aware of government plans or operations are seldom considered a threat. Because the boundaries between reality and unreality as human society perceives it has already been blurred in those suffering from mental illness, they are more prone to accept what their subconscious tells them. Thus, mentally ill contactees do not suppress their recall, but rather relay it readily to others and muse about it.
There have been cases where street people, often mentally ill and living on the street to evade being institutionalized, have been picked up to be handed over to aliens in the Service-to-Self, as part of an arrangement the CIA, as an arm of MJ12, had with these alien groups. If these unfortunate derelicts had the inner strength to just say "no" to these Service-to-Self aliens, they survived these encounters as by the rules aliens can only affect humans if they are given permission. Thus, it has indeed happened that derelicts survived such encounters and were returned to the streets, unharmed and with subconscious knowledge of what goes on. Underground chambers, the association of military guards with aliens, trips on space ships - all this knowledge was expected by the CIA to be taken by anyone hearing such tales from the mouths of madmen as simply delusions.