60s and 70s research does not meet modern standards. The validity of almost all medical and psychological research done in the era is very questionable. Some research done in this time was very good, but with psychedelics we are really starting back from square 1 because we've just begun researching it in earnest.
tl;dr If you're in medical or psychological fields and the only empirical evidence you have to back up a claim is from the 60s you are on shaky ground and need to collect more data.
tl;dr If you're in medical or psychological fields and the only empirical evidence you have to back up a claim is from the 60s you are on shaky ground and need to collect more data.