Substance Use and Dependence Following Initiation of Alcohol or Illicit Drug Use

There is a new NSDUH report on the development of dependence upon a substance in the 2 years following substance use initiation as explained below.

For the purposes of this report, persons who initiated use of a substance 13 to 24 months prior to the interview are referred to as "year-before-last initiates." Year-before-last initiates were assigned to three mutually exclusive categories reflecting their substance use trajectories following initiation: those who had not used the substance in the past 12 months ("past year"), those who had used the substance during the past year but were not dependent on the substance during the past year, and those who had used the substance and were dependent on the substance during the past year.

The report provides a peek into two interesting statistics. The first is the 2 year capture rates for each drug. That is the percentage of people who develop DSM dependence upon a drug. Please note that dependence is only one harm associated with drug use.

Percentages of Year-Before-Last Initiates Who Were Dependent on the Initiated Substance in the Past Year, by Substance: 2004-2006

The second statistic is the percentage of people who used it for the first time 2 years ago, but have not used it at all in the last year.

Percentages of Year-Before-Last Initiates Not Using the Initiated Substance in the Past Year, by Substance: 2004-2006 Does this suggest that this is the rough percentage of people who experiment with a drug briefly and then do not use it again? Does the difference between these two statistics tell us the capture rate for casual use?

I'm not sure. It will be interesting to see more about this in coming years.