The survey results appear in the most recent issue of the Journal of American College Health, published in February 2003 (but dated November 2002).
According to the researchers, the survey findings offer important insights into the experiences college students are having with alcohol - the most popular drug on American college campuses.
Nearly three-fourths of all respondents (74.2 percent) reported consuming alcohol in the two-week period prior to the survey. Of those, nearly one in 10 (9.4 percent) had experienced at least one blackout during that same time period, while 40 percent reported having experienced at least one during the previous year.
"This study shows that the common assumption that blackouts only happen to alcoholics is wrong," said Aaron White, Ph.D., assistant research professor of psychiatry at Duke and lead author of the study. "It is very possible for social drinkers, such as the students we surveyed, to experience blackouts if they overdo their consumption of alcohol. The study suggests that college students are much more familiar with blackouts than many people, including us, assumed."
Frequency of Blackouts
Using an e-mail survey, the researchers collected data from 772 undergraduate college students at Duke University during the spring 2001 semester. The student group surveyed was evenly divided among freshmen, sophomores, juniors and seniors, and between males and females. All students included in the survey were aged 18 years or older.
The survey was a 19-point questionnaire designed to acquire information on demographics, drinking habits, family history of problems with alcohol, frequency of blackouts and the types of events the students later learned they had participated in during the blackout episode.
The researchers acknowledge that while they are pleased with the survey response and sample size, they only examined students from one university. While they expect that the sample of Duke students is likely representative of a broad cross-section of American college students, they stress that larger studies need to be completed before statements can be made about blackouts among college students as a whole.
During a blackout, an individual is capable of participating in salient, emotionally charged events but will have no recollection of what has occurred. Many students in the study indicated that they later learned they had engaged in a wide range of risky activities during their blackout - such as having unprotected sexual intercourse, vandalizing property or driving a car - which could have led to serious health or legal consequences.
White stressed that due to the high level of intoxication needed to experience a blackout, other psychological processes may also be impaired.
Impairments in judgment, decision-making, and impulse control could lead an individual to make potentially hazardous choices during blackouts. The researchers believe that more information about why blackouts occur and the potential dangers associated with them need to be part of any standard alcohol-awareness training for students. Such training, they said, would be most effective if made available as early as possible upon a student's arrival on campus.
"We want to provide students with information that will help them make good, informed decisions regarding their use of alcohol," said White. "It is important for students to know what blackouts are and what factors seem to increase the risk of blackout occurrence so that they can be avoided."
The total number of blackouts experienced by students appears to correlate with lower grade point averages and other indicators of problem drinking, the researchers said. Additionally, they learned that while female students tend to drink less heavily than their male counterparts, they were just as likely as males to experience blackouts - and that, they say, could put females at greater risk for a variety of consequences.
Part Two: Rapid Consumption a Key