** "Lifetime" refers to use at least once during a respondent's lifetime. "Annual" refers to an individual's drug use at least once during the year preceding their response to the survey. "30-day" refers to an individual's drug use at least once during the month preceding their response to the survey.
** "Lifetime" refers to use at least once during a respondent's lifetime. "Annual" refers to an individual's drug use at least once during the year preceding their response to the survey. "30-day" refers to an individual's drug use at least once during the month preceding their response to the survey.
Effects%20of%20Drugs%20on%20Brain2.docx