Thanks!

1. I understand that their intent when adjusting the odds ratios was to eliminate influence of "control" or "confounding" variables. Something similar to computing partial correlations, just more complicated mathematically. But it is the choice of confounding variables here that bothers me. There are many of them. Of course, gender, age and race are ok as confoundings. But many others of these used (even income, marital status and education, not speaking about risk-taking, stressful event and use of 10 (!) other drugs) can be influenced by psychedelic use itself and can influence mental health, so being part of the same causal chain we are trying to explore. If we eliminate a big part of the causal chain, no wonder there remains no relationship. Some statistician could comment on this.
Interesting, if we take use of opiates or inhalants as "suspected cause" of symptoms and add psychedelics to same pool of confoundings, would the same procedure yield "no independent risk" also for these substances?

2. Yes, probably the respondents were asked if they have heard voices or seen visions while not under direct influence of psychedelics. Users often report visions while under influence (e.g. Hoffmann's first self-experiment with 0.25 mg LSD), voices seem to be less frequent.

No absolutely false, most of this people got the LSD sold on the street, most of the time there was no purification or quantification, in order to have a deal they would never sell 25 micrograms but at least 250 micrograms, and this is already a high dose anyway enough to make you have vision or hearing voices. Good deal on the street had between 250 and 1000 micrograms. If you took that in a reasonable way and could get directly from Switzerland before it was ban, then I can believe that you have no mental disorder. To get pure peyotl and to swallow it without throwing away is hard. To get pure psylocybin so gar in Berkeley as I can remember they were not able to synhetize it, the only one was Hoffmann in Hoffman-Laroche Switzerland. The people around SF in the ends of the sixties or at the beginning of the seventies, when they knew the right people they could get good stuff, after that we did not want anymore that became too polluted. There are alive while they knew what to take. The famous chemist of Berkeley is alive, I think He wrote a book about it. I am sorry I forgot his name. I left the US 1971.