Drug Use

Drug Use

Created Variables

FP_YYSUBSI, FP_YYSUBSI_DLI. Indicates respondent's level of substance use, with scores ranging from 0 to 3; higher scores indicate more instances of substance use since the date of the last interview. The Substance Use Index was created by Child Trends, Inc. and is available for rounds 1-4. Questions that asked respondents if they ever smoked marijuana or if they had smoked marijuana since the date of their last interview were used as part of the Substance Use Index. See the Codebook Supplement Appendix 9 for more information and statistical analysis. 

All respondents are surveyed on their experience with marijuana, which is also referred to in the survey as "grass" or "pot." In round 1, respondents were first asked whether they had ever used marijuana; if so, they reported the age at which they first used the drug. Respondents who answered "don't know," or who refused to answer this retrospective question, continue to receive the question in later rounds until a valid answer is given.  If a respondent answers affirmatively to having ever used marijuana, but cannot or will not provide the age at which they first used it, they continue to receive the age question in subsequent rounds.

Beginning in round 2, respondents who have previously provided a valid answer to the question about having ever used marijuana were asked whether they had used marijuana since the last interview, even if only once. Each survey then collected additional information on the number of days the respondent smoked marijuana in the 30 days prior to the interview. Finally, questions determined the number of times the respondent used marijuana right before or during school or work in those 30 days. This pattern continued through round 15; marijuana use questions were not asked in round 16.

The drug use questions in rounds 2 and up (through round 15--not asked in round 16) were more extensive than those in round 1. In addition to the series on marijuana use, the questionnaire asked about the use of any drugs such as cocaine, crack, heroin, or any other substance not prescribed by a doctor in order to get high or to achieve an altered state. Details collected include the respondent's age when he or she first used any of these drugs and the number of times since the last interview that the respondent took some drug or other substance. The number of times in the last 30 days that the respondent used a drug or other substance right before school or during school or work hours was also gathered. Additional questions on whether the respondent ever sold drugs are described in Crime, Delinquency & Arrest.

Comparison to Other NLS Surveys: The NLSY79 first included drug use questions in 1980, when respondents stated the number of times they had ever smoked marijuana or used other drugs. In 1984, 1988, 1992, 1994, and 1998, NLSY79 respondents reported their age at first use, lifetime use, and frequency of use in the past 30 days. In addition, NLSY79 females were asked about use of marijuana immediately prior to and during pregnancy. Children of the NLSY79 age 10 and older (including the Young Adults) have been asked about their use of various drugs in the past 3 months since the 1988 survey. For more information, refer to the NLSY79 Child & Young Adult User's Guide.

Survey Instruments: All the questions on drug use are found in the self-administered section (question names begin with YSAQ) of the Youth Questionnaire.

Related User's Guide Sections Alcohol Use
Cigarette Use
Crime, Delinquency & Arrest
Main Area of Interest Substance Use
Family Process Measures
Supplemental Areas of Interest Illegal Activity & Arrest