"What does that mean adjusted?"
It's explained the study.
"About this time is where I say a study has too many methodological flaws and should be disregarded."
Try actually reading it. It's really not that difficult to understand. The 'maturity recanting effect' section here also gives a brief summary of what they did and why:
http://www.erowid.org/psychoactives/statistics/statistics_ar...
Don't criticize studies without taking the time to understand them, otherwise you just sound like these people: