Estimates are displayed in U.S. maps and tables. To produce the marijuana use map (Figure 1), state estimates were first rank ordered from lowest to highest and then divided into quintiles (fifths). States with the lowest estimates (i.e., the lowest fifth) are assigned to the bottom quintile and are shown in dark blue. States with the highest estimates are assigned to the top quintile and are shown in dark red. All other states are assigned to one of three quintiles between the lowest and highest quintiles. Figure 2, the map showing perceived great risk from smoking marijuana monthly, was produced in a similar fashion, except that the rank ordering was done in reverse order so that the lower estimates of youths' perceptions of risk of marijuana use are assigned to the top quintile and are shown in dark red. Supporting tables associated with the maps (Tables S1 and S2) provide estimates that are rank ordered from highest to lowest and divided into quintiles (fifths).¹²

Tables 1 and 2 show comparisons between estimates for combined 2013–2014 data and estimates for combined 2012–2013 data to examine changes over time. In these tables, estimates for the states are listed alphabetically. Ninety-five percent confidence intervals are included as a measure of precision for each estimate. Figure 3 is a map summarizing these changes (supporting Table S3). The inclusion of a common year (i.e., 2013) in these comparisons increases the precision of the estimates and the ability to detect statistically significant differences between the two time periods. Statistically significant differences between 2013–2014 and 2012–2013 indicate average annual changes between 2012 and 2014. All changes discussed in this report are statistically significant at the .05 level.¹³

Columbia).¹⁴ Of the 10 states with the lowest rates of marijuana use among adolescents, 5 were in the South (Alabama, Oklahoma, Louisiana, West Virginia, and Mississippi), 4 were in the Midwest (Iowa, South Dakota, Nebraska and North Dakota), and 1 was in the West (Utah).

When combined 2012–2013 estimates are compared with combined 2013–2014 estimates, the nation as a whole did not experience a significant change in the rate of past month marijuana use among adolescents (7.15 percent in 2012–2013 and 7.22 percent in 2013–2014) (Table 1).

On an individual state level, three states experienced a statistically significant decrease in the rate of adolescent past month marijuana use (Hawaii: from 9.55 to 7.65 percent, Ohio: from 7.36 to 6.04 percent, and Rhode Island: from 12.95 to 10.69 percent). The remaining 47 states and the District of Columbia experienced no change in past month marijuana use.

Comparisons between the combined 2012–2013 and combined 2013–2014 NSDUH data indicate that there was a slight decrease at the national level in the adolescent rate of perception of great risk from smoking marijuana once a month (from 25.34 to 23.54 percent) (Table 2).

On an individual state level, 14 states experienced a statistically significant decline in the percentage of adolescents who perceived great risk from smoking marijuana (District of Columbia, Georgia, Illinois, Indiana, Kansas, Mississippi, Nevada, North Dakota, Oklahoma, South Dakota, Tennessee, Texas, Washington, and Wisconsin). Rates of perceived great risk in the remaining 37 states did not change.

Taken together, the three states that had a statistically significant decrease in past month adolescent marijuana did not have any change in adolescent’s rate of perception of great risk from smoking marijuana once a month (Figure 3; Table S3); these states are Hawaii, Ohio, and Rhode Island.¹³ The 14 states that had a significant decrease in adolescent’s rate of perception of great risk from smoking marijuana once a month did not experience any significant change in the rate of past month adolescent marijuana use. In 34 states, there were no statistically significant changes in either adolescent past month marijuana use or in adolescent perception of great risk from smoking marijuana.

Monitoring trends in adolescent marijuana use remains a concern both across the states and in the nation as a whole because of the health risks associated with youth marijuana use.² The NSDUH data in this report show that youth marijuana use remained unchanged in 48 states and declined in 3 states between 2012–2013 and 2013–2014. However, 14 states saw a decline in the percentage of adolescents’ perceived great risk in smoking marijuana once a month. Declines in adolescent perceptions of risk matter because, as seen from Tables 1 and 2, there is a significant negative relationship between adolescent marijuana use and perceived great risk at the state level. That is, states with higher rates of marijuana use were more likely to have lower percentages of adolescents who think there is great risk in using marijuana, whereas states with lower rates of use tend to have higher percentages of adolescents who think there is great risk in using marijuana.¹⁵ 

Changing attitudes toward substance use has historically been a way to reduce substance use among youths.⁸ However, the 2013–2014 NSDUH data indicate that youths' perceptions of risk have decreased in many states, although the rates of marijuana use among youths have remained the same in nearly every state. Although there has not been a corresponding increase in adolescent marijuana use, the decline in adolescent perceptions of the riskiness of marijuana use still remains concerning because approximately 3,300 adolescents aged 12 to 17 initiated marijuana use each day in 2014.⁸ 

Across the nation in 2013–2014, approximately 1.8 million adolescents were past month marijuana users, and about three-fourths of adolescents across all states did not think there was great risk of harm from using marijuana. Highlighting the prevalence of adolescent marijuana use and attitudes toward use at the state level may help state and local prevention specialists in their efforts to raise awareness about marijuana use among youths and its consequences. As states continue to examine their laws regarding marijuana use, monitoring state-level trends in adolescent marijuana use and attitudes toward use may also help state and local policymakers plan for and allocate resources to address adolescent marijuana use. For more information on addressing marijuana use among youths, see https://www.samhsa.gov/capt/tools-learning-resources/youth-marijuana-risk-protective-factor-resources.

The combined 2013–2014 NSDUH state estimates of past month marijuana use, perceived great risk from monthly marijuana use, and 23 additional behavioral health measures are available online at https://www.samhsa.gov/data/. The 23 additional measures are substance use and mental health outcomes, including initiation and use of illicit drugs (e.g., marijuana initiation, cocaine use, and nonmedical use of prescription pain relievers); alcohol and tobacco use; perceived great risk of harm associated with alcohol and cigarette use; substance use disorders; needing but not receiving treatment for a substance use problem; serious mental illness; any mental illness; depression; and suicidal thoughts. National maps for all outcomes and detailed tables including percentages and counts for each state, census region, and the nation, by age group, also are provided as well as the methodology that generated the state estimates.

Hughes, A., Lipari, R.N., & Williams, M. The CBHSQ Report: State Estimates of Adolescent Marijuana Use and Perceptions of Risk of Harm From Marijuana Use: 2013 and 2014. Rockville, MD: Substance Abuse and Mental Health Services Administration, Center for Behavioral Health Statistics and Quality.

1. Center for Behavioral Health Statistics and Quality. (2015). Behavioral health trends in the United States: Results from the 2014 National Survey on Drug Use and Health (HHS Publication No. SMA 15–4927, NSDUH Series H–50). Rockville, MD: Substance Abuse and Mental Health Services Administration.
2. Volkow, N. D., Baler, R. D., Compton, W. M., & Weiss, S. R. B. (2014). Adverse health effects of marijuana use. New England Journal of Medicine, 370(23), 2219–2227. doi: 10.1056/NEJMra1402309
3. Fergusson, D. M., & Boden, J. M. (2008). Cannabis use and later life outcomes. Addiction, 103(6), 969–976; discussion 977–8. doi: 10.1111/j.1360-0443.2008.02221.x
4. Meier, M. H., Caspi, A., Ambler, A., Harrington, H., Houts, R., Keefe, R. S., McDonald, K., Ward, A., Poulton, R., & Moffitt, T. E. (2012). Persistent cannabis users show neuropsychological decline from childhood to midlife. Proceedings of the National Academy of Sciences of the United States of America, 109(40), E2657–E2664. doi: 10.1073/pnas.1206820109
5. Gruber, S. A., Dahlgren, M. K., Sagar, K. A., Gönenç, A., & Lukas, S. E. (2014). Worth the wait: Effects of age of onset of marijuana use on white matter and impulsivity. Psychopharmacology, 231(8), 1455–1465. doi: 10.1007/s00213-013-3326-z
6. Brady, J. E., & Li, G. (2014). Trends in alcohol and other drugs detected in fatally injured drivers in the United States, 1999–2010. American Journal of Epidemiology, 179(6), 692–699. doi: 10.1093/aje/kwt327
7. Chen, C. Y., Storr, C. L., & Anthony, J. C. (2009). Early-onset drug use and risk for drug dependence problems. Addictive Behaviors, 34(3), 319–322. doi: 10.1016/j.addbeh.2008.10.021
8. Lipari, R., Kroutil, L. A., & Pemberton, M. R. (2015, October). NSDUH Data Review: Risk and protective factors and initiation of substance use: Results from the 2014 National Survey on Drug Use and Health. Rockville, MD: Substance Abuse and Mental Health Services Administration, Center for Behavioral Health Statistics and Quality.
9. Miech, R. A., Johnston, L. D., O'Malley, P. M., Bachman, J. G., & Schulenberg, J. E. (2015). Monitoring the Future national survey results on drug use, 1975–2014: Volume I, secondary school students. Ann Arbor, MI: Institute for Social Research, University of Michigan.
10. All estimates in this report are based on a small area estimation (SAE) methodology in which state-level NSDUH data are combined with local-area county and census block group/tract-level data from the state. This model-based methodology provides more precise estimates of substance use at the state level than those based solely on the sample, particularly for smaller states. The precision of the SAE estimates, particularly for states with smaller sample sizes, can be improved significantly by combining data across 2 years (i.e., 2012 and 2013, 2013 and 2014).
11. The difference in sample sizes between 2012–2013 and 2013–2014 is due to a sample redesign in 2014. For additional information, go to https://www.samhsa.gov/data/.
12. In this report, state estimates are discussed in terms of their observed rankings because they provide useful context. However, a state having a highest or lowest rate does not imply that the state's rate is significantly higher or lower than the rate of the next highest or lowest state. When comparing two state prevalence rates, the method of overlapping confidence intervals is more conservative (i.e., it rejects the null hypothesis of no difference less often) than the standard method based on Z statistics when the null hypothesis is true. Even if confidence intervals for two states overlap, the two estimates may be declared significantly different by the test based on Z statistics. Hence, the method of overlapping confidence intervals is not recommended to test the difference of two state estimates. A detailed description of the method of overlapping confidence intervals and its comparison with the standard methods for testing of a hypothesis is given in the following articles: (a) Schenker, N., & Gentleman, J. F. (2001). On judging the significance of differences by examining the overlap between confidence intervals. American Statistician, 55(3), 182–186. (b) Payton, M. E., Greenstone, M. H., & Schenker, N. (2003). Overlapping confidence intervals or standard error intervals: What do they mean in terms of statistical significance? Journal of Insect Science, 3, 34.
13. Tests of significance were conducted separately on the difference in the rates of marijuana use from 2012-2013 to 2013-2014 and the difference in the percentage perceiving great risk for the same two time periods. However, no tests of significance were conducted jointly between the difference in marijuana use and the difference in the perceptions of great risk.
14. The West has 13 states: AK, AZ, CA, CO, HI, ID, MT, NM, NV, OR, UT, WA, and WY. The South has 16 states plus the District of Columbia: AL, AR, DE, FL, GA, KY, LA, MD, MS, NC, OK, SC, TN, TX, VA, and WV. The Northeast has 9 states: CT, MA, ME, NH, NJ, NY, PA, RI, and VT. The Midwest has 12 states: IA, IL, IN, KS, MI, MN, MO, ND, NE, OH, SD, and WI.
15. For 2013–2014, the correlation between the 51 state estimates of past month marijuana use and the 51 state estimates of perceived great risk in using marijuana monthly is -0.86.