# Presentation: 667262

## 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

## 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.

## 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?

## 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)

## 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

## 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

## Results:  Total  Population

- %

## 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 < .01)

***How consistent are these results across age groups, race/ethnic groups and sexes?**** *

## Results:  Marijuana Use by Sex and Race/Ethnicity

**%**

## Results:  Marijuana Use In Age Groups

**%**

## Results:  Marijuana Use in Whites

**%**

## Results:  Marijuana Use in Blacks

**%**

## Results:  Marijuana Use in Hispanics

**%**

## Results:  Marijuana Use in Men

**%**

## Results:  Marijuana Use in Women

**%**

## 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

- 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

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

## 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

- 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

**Results:  Summary of Marijuana Use**

## Results:  Marijuana Abuse or Dependence in Overall Population

## Results:  Marijuana Abuse or Dependence by Sex and Race/Ethnicity

**%**

## Results:  Marijuana Abuse or Dependence in Whites

**%**

## Results:  Marijuana Abuse or Dependence in Blacks

**%**

## Results:  Marijuana Abuse or Dependence in Hispanics

**%**

## Results:  Marijuana Abuse or Dependence in Men

**%**

## Results:  Marijuana Abuse or Dependence in Women

**%**

## 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

- 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

**Results:  Summary of Marijuana ****Abuse or Dependence**

## Results:  Marijuana Abuse or Dependence Among Users in Overall Population

## Results:  Marijuana Abuse or Dependence among Users, by Sex and Race/Ethnicity

**%**

## Results:  Marijuana Abuse or Dependence Among Black Users

**%**

## Results:  Marijuana Abuse or Dependence  Among White Users

**%**

## Results:  Marijuana Abuse or Dependence  Among Hispanic Users

**%**

## Results:  Marijuana Abuse or Dependence  Among Male Users

**%**

## Results:  Marijuana Abuse or Dependence  Among Female 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

- 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

**Results:  Summary of Marijuana ****Abuse or Dependence Among Users**

## Estimated Population Increases in Marijuana Abuse or Dependence

## Why have rates increased?

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

## Why have rates increased?

- Changes in quantity/frequency of marijuana use?

- Not likely...

## Changes in Frequency of MJ Use?

**%**

## Changes in Quantity of MJ Smoked?

**%**

## Why have rates increased?

- Changes in potency of marijuana?

- 		Possibly...

## Changes in Potency of Marijuana

- Source:  Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi; 2003

## Why have rates increased?

- Psychosocial factors?

- Possibly...

## 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?

## 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.

## 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

- Increased potency of marijuana may play a role

**Summary**

## 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