Teen Marijuana Use - Medical Marijuana

Last updated on: 2/5/2009 3:43:00 PM PST

Teen Marijuana Use
Teen (Age 12-17) Marijuana Use and State Medical Marijuana Laws, 1999-2006

Teen Marijuana Use in States with Legal Medical Marijuana vs. States Without It

Percentage of Teen Marijuana Use in 10 States with Legal Medical Marijuana

Statistically Significant Changes in Teen Past Month Marijuana Use

A. States Ranked by Percentage of Teens Reporting Past Month Marijuana Use
B. Changes in Rank and Teen Use in States with Legal Medical Marijuana

Related Links and Sources

I. Teen Marijuana Use in States with Legal Medical Marijuana vs. States Without It

Notes:

ProCon.org created the above graph using data for past month teen marijuana use from the Substance Abuse and Mental Health Services Administration (SAMHSA) National Household Surveys on Drug Abuse (NHSDA), 1999-2006. The 2006 data is the most recently available data as of Jan. 26, 2009.

Since medical marijuana became legal in different years in certain states, the percentage for each year on the line showing "legal" states includes only those states that had legalized medical marijuana on or before that year. The percentage for 1999 is therefore the average of Alaska, California, Maine, Oregon, and Washington; 2000-03 includes Alaska, California, Colorado, Hawaii, Maine, Nevada, Oregon, and Washington; 2004-06 includes Alaska, California, Colorado, Hawaii, Maine, Montana, Nevada, Oregon, Vermont, and Washington.

Please note that data for all 50 states are only available for 1999 through 2006. In 1999, there were 5 states with legal medical marijuana; by 2005, 10 states had legalized it. As of Jan. 12, 2009, there were 13 states with laws legalizing medical marijuana. Since Rhode Island, New Mexico, and Michigan passed medical marijuana in 2006, 2007, and 2008, in this graph they are included in the average of states where medical marijuana is illegal.

State by state data on teen marijuana use prior to 1999 were not available.

II. Percentage of Teen Marijuana Use in 10 States with Legal Medical Marijuana

Ten states had legalized medical marijuana by 2006; seven of those ten passed the laws between 1999 and 2006, the years for which the teen use data are available for all states.

Four of the seven states that passed medical marijuana laws between 1999 and 2006 had a decrease in average teen marijuana use the year after the law was passed. The other three states showed an increase the year after the law was passed. Six of the seven states had a lower percentage of teen use in 2006 than the year in which they legalized medical marijuana.

Eight of the ten states that had legalized medical marijuana as of 2006 had a lower percentage of teen use in 2006 than in 1999, while the other two ended with higher average teen use percentages in 2006 than in 1999.

	Average Past Month Teen Marijuana Use (%) in States with Legal Medical Marijuana 1999-2006
State (year legalized)	1999	2000	2001	2002	2003	2004	2005	2006	(1999-2006)
Alaska (1999)	10.40	8.65	9.88	9.44	11.08	12.02	9.71	8.26	(-2.14%)
California (1996)	7.70	7.50	8.16	7.60	7.66	8.52	7.50	6.51	(-1.19%)
Colorado (2000)	10.30	10.80	10.96	9.87	9.82	9.83	9.24	7.44	(-2.86%)
Hawaii (2000)	8.30	8.72	9.32	9.30	10.23	9.71	7.61	7.04	(-1.26%)
Maine (1999)	7.20	9.25	11.12	9.60	10.56	11.69	12.27	10.99	(+3.79%)
Montana (2004)	11.40	9.26	9.32	11.64	12.07	10.00	9.50	10.56	(-0.84%)
Nevada (2000)	11.60	9.54	9.32	11.24	9.58	7.82	6.98	7.57	(-4.03%)
Oregon (1998)	9.60	9.39	9.07	8.72	9.31	9.74	9.30	8.36	(-1.24%)
Vermont (2004)	8.40	10.62	13.20	13.31	13.32	11.11	10.54	10.08	(+1.68%)
Washington (1996)	9.90	8.70	9.56	8.93	9.11	7.98	6.83	7.70	(-2.20%

Notes:

ProCon.org created the above table using data for past month teen marijuana use from the Substance Abuse and Mental Health Services Administration (SAMHSA) National Household Surveys on Drug Abuse (NHSDA), 1999-2006.

III. Statistically Significant Changes in Teen Past Month Marijuana Use

"Measuring the likelihood that an event occurs by chance is the idea behind 'statistical significance.' If there is, at most, a five percent chance of two events would happen together by coincidence, we may legitimately infer that there is a reason that the events occurred together. Such results are called statistically significant, and the events are considered correlated. If there is more than a five percent chance of occurring randomly, the possibility that the events occurred together just by luck is too high to dismiss, and we conclude nothing.

The five percent line is arbitrary, but has become standard in the field of biomedical research; statistical significance is the golden measuring stick for evaluating data... For the sake of having a standard of some kind, scientists have agreed on p=.05. A result that is statistically significant has more weight in the scientific community than one that is not."
Oct. 16, 2007 Statistical Assessment Service (STATS)

	Statistically Significant Changes
State (year legalized)	1999-2000	2000-2001	2001-2002	2002-2003	2003-2004	2004-2005	2005-2006
Alaska (1999)	-	-	-	-	-	- 2.31%	-
California (1996)	-	-	-	-	-	- 1.02%	-
Colorado (2000)	-	-	-	-	-	-	-
Hawaii (2000)	-	-	-	-	-	- 2.10%	-
Maine (1999)	-	-	-	-	-	-	-
Montana (2004)	-	-	-	-	- 2.07%	-	-
Nevada (2000)	-	-	-	-	-	-	-
Oregon (1998)	-	-	-	-	-	-	-
Vermont (2004)	-	-	-	-	-	-	-
Washington (1996)	-	-	-	-	-	-	-
National Average	-	+.40%	-	-	-	- .53%	-.46%

Notes:

The lack of an increase in teen marijuana use in states that legalized medical marijuana appears to disprove the argument that legalizing medical marijuana would lead to increased teen use of marijuana for recreational purposes. The cause of the decrease in teen use, however, cannot be determined without additional information and statistical analysis.

IV. States Ranked by Percentage of Teens Reporting Past Month Marijuana Use

A. Rank and Percent Use by State:
The tables below show the rank of each state, including the District of Columbia and the national average, from highest percentage of past month teen marijuana use to lowest. The ten states that had legalized medical marijuana as of 2006 are shown in bold. The year in which each state legalized medical marijuana is noted in parentheses in the state rank table for 2006.

1999
Rank	State	% Teen Use
1	Delaware	13.9%
2	Massachusetts	11.9%
3	Nevada	11.6%
4	Montana	11.4%
5	Rhode Island	10.8%
6	New Hampshire	10.7%
7	Alaska	10.4%
8	Colorado	10.3%
9	Minnesota	9.9%
9	Washington	9.9%
11	Oregon	9.6%
	District of Columbia	9.6%
12	Illinois	9.2%
12	New Mexico	9.2%
14	Maryland	8.8%
15	Indiana	8.7%
16	Connecticut	8.6%
17	Vermont	8.4%
18	Hawaii	8.3%
18	Wisconsin	8.3%
20	Michigan	7.8%
20	Wyoming	7.8%
22	California	7.7%
23	North Dakota	7.6%
	National	7.4%
24	South Carolina	7.4%
27	Arizona	7.3%
27	Arkansas	7.3%
27	New Jersey	7.3%
28	Maine	7.2%
29	West Virginia	7.1%
31	Ohio	6.9%
31	South Dakota	6.9%
33	New York	6.8%
33	North Carolina	6.8%
34	Mississippi	6.7%
37	Kansas	6.6%
37	Louisiana	6.6%
37	Missouri	6.6%
38	Georgia	6.4%
40	Oklahoma	6.3%
40	Pennsylvania	6.3%
41	Florida	6.2%
43	Nebraska	6.1%
43	Utah	6.1%
45	Idaho	5.9%
45	Virginia	5.9%
46	Texas	5.7%
47	Alabama	5.6%
48	Kentucky	5.3%
50	Iowa	5.2%
50	Tennessee	5.2%

2006
Rank	State	% Teen Use
1	Maine (1999)	10.99%
2	Montana (2004)	10.56%
3	Vermont (2004)	10.08%
4	Rhode Island	9.74%
5	Massachusetts	8.96%
6	Connecticut	8.40%
7	Oregon (1998)	8.36%
8	Alaska (1999)	8.26%
9	New Hampshire	8.21%
10	New York	7.81%
11	New Mexico	7.79%
12	Arkansas	7.71%
13	Washington (1996)	7.70%
14	Wyoming	7.63%
15	Nevada (2000)	7.57%
16	Minnesota	7.53%
17	Colorado (2000)	7.44%
18	Michigan	7.32%
19	Delaware	7.31%
20	Arizona	7.24%
21	Hawaii (2000)	7.04%
22	North Carolina	7.02%
23	Ohio	6.97%
24	Florida	6.92%
25	West Virginia	6.82%
	District of Columbia	6.81%
	National	6.74%
26	Illinois	6.73%
27	Kentucky	6.59%
28	Wisconsin	6.58%
29	Kansas	6.57%
30	South Dakota	6.56%
31	Iowa	6.55%
32	California (1996)	6.51%
33	Missouri	6.45%
34	Virginia	6.39%
35	Pennsylvania	6.37%
36	Oklahoma	6.36%
37	New Jersey	6.35%
38	Alabama	6.32%
39	Indiana	6.17%
40	South Carolina	6.06%
41	Idaho	5.91%
42	Georgia	5.85%
43	Tennessee	5.73%
44	Louisana	5.65%
45	Maryland	5.63%
46	Texas	5.56%
47	Nebraska	5.52%
48	Mississippi	5.36%
49	Utah	5.08%
50	North Dakota	4.51%

B. Change in Rank and Percent Use in States with Legal Medical Marijuana:
Four states with legal medical marijuana ranked higher in 2006 than in 1999, meaning the teen marijuana use in those states went up relative to other states, and six states ranked lower. Eight states with legal medical marijuana had a lower percentage of teen marijuana use in 2006 than in 1999, while two states had a higher percentage. Please note on the table below that a "+" indicates the state moved closer to rank #1 (highest teen marijuana use), while a "-" indicates that the state moved closer to rank #50 (lowest teen marijuana use).

Changes in Rank and Teen Use in States with Legal Medical Marijuana
State	Change in rank from 1999 to 2006	Change in teen use from 1999 to 2006
Alaska	-1	-2.14%
California	-10	-1.19%
Colorado	-9	-2.86%
Hawaii	-3	-1.26%
Maine	+27	+3.79%
Montana	+2	-.84%
Nevada	-12	-4.03%
Oregon	+4	-1.24%
Vermont	+14	+1.68%
Washington	-4	-2.20%
Net	+8	-10.29%

Notes:

The data on past month teen marijuana use provided by Substance Abuse and Mental Health Services Administration (SAMHSA) were presented to one decimal place for 1999 (0.0) and switched to hundreths (0.00) from 2000-2006.

Mark Eddy, Specialist in Illicit Drug Control Policy at the Congressional Research Service (CRS), in his July 27, 2007 report Medical Marijuana: Review and Analysis of Federal and State Policies (updated Apr. 2, 2010), noted a common argument of critics of medical marijuana:

"They point to the 1999 National Household Survey on Drug Abuse (NHSDA), which 'reveals that those states which have passed medical marijuana laws have among the highest levels of past-month marijuana use, of past-month other drug use, of drug addiction, and of drug and alcohol addiction.' [...] It is at least possible, however, that this analysis confuses cause with effect...It is logical to assume that the states with the highest prevalence of marijuana usage would be more likely to approve medical marijuana programs, because the populations of those states would be more knowledgeable of marijuana's effects and more tolerant of its use."
CRS Report for Congress: "Medical Marijuana: Review and Analysis of Federal and State Policies" (515 KB)