According to Dr. Stanislav Grof who has done more research on LSD than probably almost anyone in the world, "bad trips" in LSD merely mean that material has been accessed which has never been worked through. Now before you brush aside what he has to say, he was an assistant Professor of psychiatry at Johns Hopkins University school of medicine, and a former Chief of Psychiatric Research at the Maryland Psychiatric Research Center who is as respected for his psychedelic research as anyone you could mention.
Read his answer to to the following question, which is pretty much what this topic is about:
LSD has been both demonized and lionized. What do you think is the single greatest misconception about LSD?
"I would say these two reactions reflect the basic misconception, that LSD is either good or bad. It is neither. By itself, LSD has no intrinsic healing potential, nor does it have any intrinsic destructive potential. The outcome depends on who is doing it, with whom, for what purpose and under what circumstances. Yet everything that happens under the influence of LSD tends to be credited or blamed on the drug itself.
Years ago, during the initial flurry of bad publicity over LSD, I had a very interesting discussion with Professor Humphrey Osmond, one of the early pioneers of LSD research. He pointed out the ridiculous turn the debate had taken by pointing out that LSD is just a tool. He said if the worth of some other tool, a knife for instance, was discussed in the same way LSD was, you'd have a policeman saying it was bad, while pushing statistics of people killed with knives in back alleys. A surgeon would see it as good, pointing out the healing possibilities of the knife. A housewife might talk about cutting salami. An artist might talk about wood carving. As you can see, what is being said says less about the knife than about how it is used. We don't make the mistake of blaming or crediting the knife with how it's used, but with LSD it's all kind of thrown together."
As someone who has taken more than my fair share LSD I'd say that metaphor is LSD in a nutshell. Like I've said before I do not think LSD should be legal or even available to youngsters who take it recreationally at parties. In the wrong hands it is way too dangerous and the risks are too high. In the hands of someone who is prepared and has respect for the experience that person can emerge more whole and integrated with reality than they were before.
But the question this topic asks is if it has any benefits, and to nullify the many positive outcomes in previous studies because of the adverse effects in some is just arrogant and unacademic. We ALL know that it can be extremely dangerous! That isn't what's up for discussion.