Marijuana Use Disorders in the United States: 1991-1992 and 2001-2002

1
Marijuana Use Disorders in the United States
1991-1992 and 2001-2002

• Wilson M. Compton, M.D., M.P.E.
• Director, Division of Epidemiology, Services and
  Prevention Research
• National Institute on Drug Abuse
• Department of Health and Human Services

May 5, 2004 American Psychiatric Association
Annual Meeting
2
Background
A great deal of information about trends in use
of drugs is available, but no data provides
reliable and valid measures of drug disorders
over the past decade.
3
Background

• With data from two large household surveys of the
  U.S. adult population, this study seeks to answer
  the following questions
• What are the rates of marijuana abuse and
  dependence in 1991-1992 compared to 2001-2002?
• Have the relationships of age, race/ethnicity or
  gender to marijuana abuse and dependence changed
  during this period?

4
Methods

• Studies
• Large studies of the U.S. non-institutionalized
  household adult (18) population conducted by the
  Census Bureau.
• NLAES National Longitudinal Alcohol
  Epidemiologic Study (N 42,862)
• NESARC National Epidemiologic Study of Alcohol
  and Related Conditions (N 43,093)

5
Methods

• Interview
• AUDADIS Alcohol Use Disorder and Related
  Disabilities Interview Schedule - DSM-IV Version
• Specific measures of each criterion of abuse and
  dependence on marijuana
• Reliability and validity well-established

6
Methods

• Outcomes
• Marijuana use, abuse and dependence in overall
  population and by age, race/ethnicity and sex
• Marijuana abuse and dependence among marijuana
  users by age, race/ethnicity and sex

7
Results Total Population

8
Results Total Population

• Comparing 1991-1992 to 2001-2002
• Marijuana use rates were virtually the same
  4.0 versus 4.1
• Marijuana abuse or dependence increased from 1.2
  to 1.5 (p .014)
• Marijuana abuse or dependence among users
  increased from 30.2 to 35.6 (p lt .01)

How consistent are these results across age
groups, race/ethnic groups and sexes?
9
Results Marijuana Use by Sex and Race/Ethnicity

10
Results Marijuana Use In Age Groups

11
Results Marijuana Use in Whites

12
Results Marijuana Use in Blacks

13
Results Marijuana Use in Hispanics

14
Results Marijuana Use in Men

15
Results Marijuana Use in Women

16
Results Marijuana Use in Detailed
Age-Sex-Race/Ethnicity Categories

• Use increased significantly for
• White males 45-64 years old
• Black females overall and Black females 18-29 and
  46-64 years old
• Hispanic females 18-29 years old

17
Results Summary of Marijuana Use

• Rates did not change significantly overall
• Rates increased significantly for
• 18-29 and 45-64 year olds
• Black and Hispanic 18-29 year olds
• White and Black 45-64 years olds
• Women 18-29 years old and both men and women
  45-64 years old
• Selected age-sex-race/ethnicity categories

18
Results Marijuana Abuse or Dependence in
Overall Population
19
Results Marijuana Abuse or Dependence by Sex
and Race/Ethnicity

20
Results Marijuana Abuse or Dependence in Whites

21
Results Marijuana Abuse or Dependence in Blacks

22
Results Marijuana Abuse or Dependence in
Hispanics

23
Results Marijuana Abuse or Dependence in Men

24
Results Marijuana Abuse or Dependence in Women

25
Results Summary of Marijuana Abuse or
Dependence

• Rates increased significantly overall
• Increases in rates were significant for
• 18-29 and 45-64 year olds overall
• Blacks and Hispanics overall and 18-29 years old
• Women overall and 18-29 years old
• Men 45-64 years old
• Black and Hispanic men overall and 18-29 years
  old
• Black women overall and 18-29 years old

26
Results Marijuana Abuse or Dependence Among
Users in Overall Population
27
Results Marijuana Abuse or Dependence among
Users, by Sex and Race/Ethnicity

28
Results Marijuana Abuse or Dependence Among
Black Users

29
Results Marijuana Abuse or Dependence Among
White Users

30
Results Marijuana Abuse or Dependence Among
Hispanic Users

31
Results Marijuana Abuse or Dependence Among
Male Users

32
Results Marijuana Abuse or Dependence Among
Female Users

33
Results Summary of Marijuana Abuse or
Dependence Among Users

• Rates increased significantly overall
• Increases in rates were significant for
• 18-29 and 30-44 year olds overall
• Blacks overall and 30-44 and 18-29 years old
• Hispanics overall and 18-29 years old
• Women and men overall and 18-29 years old
• Black and Hispanic men overall and 18-29 years
  old
• Black women overall and 18-29 years old

34
Estimated Population Increases in Marijuana
Abuse or Dependence
35
Why have rates increased?

• Changes in quantity/frequency of marijuana use?
• Changes in potency of marijuana?
• Psychosocial factors?

36
Why have rates increased?

• Changes in quantity/frequency of marijuana use?
  

Not likely
37
Changes in Frequency of MJ Use?

38
Changes in Quantity of MJ Smoked?

39
Why have rates increased?

• Changes in potency of marijuana?

Possibly
40
Changes in Potency of Marijuana
Source Research Institute of Pharmaceutical
Sciences, School of Pharmacy, University of
Mississippi 2003
41
Why have rates increased?

• Psychosocial factors?

Possibly
42
Plausible Psychosocial Factors

• Acculturation?
• Lifestyle factors and attitudinal factors?
• Sociodemographic or socioeconomic factors?
• Economic factors such as price, tax and policy
  changes affecting other substances that may
  inadvertently affect marijuana?
• Historical and cultural factors?

43
Summary

• Rates of Marijuana use were nearly the same in
  the total population in 1991-1992 as in
  2001-2002, but increases were seen in certain
  subgroups
• younger male and female blacks,
• younger Hispanic males
• white and black 45-64 year olds.

44
Summary

• Marijuana-related disorders (abuse and
  dependence) increased from 1991-1992 to
  2001-2002, especially for younger male and female
  blacks and younger hispanic males.
• Increased potency of marijuana may play a role

45
Marijuana Use Disorders in the United States
1991-1992 and 2001-2002

• Wilson M. Compton, M.D., M.P.E. - NIDA
• Bridget F. Grant, Ph.D., Ph.D. - NIAAA
• James D. Colliver, Ph.D. - NIDA
• Meyer D. Glantz, Ph.D. - NIDA
• Frederick S. Stinson, Ph.D. - NIAAA