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User's Guide - Learn the Facts

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What’s the difference between tolerance and dependence?

Tolerance = needing more of a drug or alcohol to acquire an effect that was previously achieved at a lower dose.

Dependence = when stopping drug or alcohol use becomes physically and psychologically difficult. The user may experience withdrawal symptoms like nausea, sweating, or shaking.

Recovery From...

  • Discover facts and statistics on mental and/or substance use disorders and co-occurring disorders. Integrate what you’ve learned into presentations, fact sheets, and more.

    Substance use disorders?

  • Use of alcohol or drugs that is compulsive or dangerous (or both)1.

  • Characteristics include:

    • Continued use of alcohol or a drug in spite of the negative consequences
    • Denial
    • Tolerance
    • Craving
    • Loss of Control
    • Physical dependence or withdrawal symptoms

    Learn More


    • In 2011, an estimated 20.6 million people, aged 12 or older experienced substance dependence or abuse in the past year. That means almost 8.0% of the population suffer from a substance use disorder3.
    • Approximately 82.2% of college students in two-to-four-year schools consumed alcohol over the past year; 69.2% drank alcohol over the past 30 days; 61.2% were underage; and 43.9% reported binge drinking in the previous two weeks4.
    • On the illicit side, 31.3% of students have used marijuana in the past year, and 18.1% were current users; 11.0% have used an illegal drug other than marijuana in the past year; and 5.5% are current users of illegal drugs other than marijuana5.
    • Among those aged 18-25, the rate of current nonmedical use of prescription drugs in 2011 was 5.0%6.

    Mental disorders?

  • Common mental disorders include anxiety and mood disorders (such as clinical depression or bipolar disorders). Like substance use disorders, these problems are highly treatable. Symptoms include:

    • Unable to cope with problems and daily activities.
    • Changes in sleeping and/or eating habits.
    • Defiance of authority and/or substance use.
    • Dramatic changes in mood and/or behavioral habits and prolonged negativity.
    • Excessive fears, anxieties, anger, and/or suicidal thoughts.
    • Denial of obvious problems.
    • Numerous unexplained physical ailments.
    • Excessive absenteeism from school or work.


    • Mental disorders are common in the United States and internationally. An estimated 26.2% of Americans ages 18 and older — about one in four adults — suffer from a diagnosable mental disorder in a given year…this figure translates to 57.7 million people.7.
    • In a given year, less than half of people diagnosed with a mental illness receive treatment8.
    • According to a recent study by Hofstra University’s John Guthman, PhD, over the last 10 years, students coming into school counseling centers are experiencing more severe psychological problems, including mood, anxiety, and adjustment disorders. In fact, the study concludes that more young people are arriving on campuses with pre-existing conditions than they were 10 years ago, and one-in-four college students is on psychiatric medication9.

    Co-occurring disorders?

  • People who are experiencing problems with substance use often have a mental disorder at the same time and vice versa.


    • Approximately 8.9 million adults have co-occurring disorders. Only 7.4% receive treatment with over half (55.8%) receiving no treatment at all10.
    • In a recent Harvard College Alcohol Study survey of college students, researchers found that students considered to have poor mental health or depression (PMHD) were more likely to report drinking, drinking to get drunk, and to experience drinking-related problems, such as falling behind in work, vandalizing, having unsafe sex, and overdosing11.
    • Evidence suggests that those with co-occurring substance abuse and mental health disorders – particularly those who aren’t treated – are at high risk of relapse, experience poor treatment outcomes, and often move to higher levels of substance use12.


    1. ^ Center for Substance Abuse Treatment, What Is Substance Abuse Treatment? A Booklet for Families, DHHS Publication No. (SMA) 04-3955. Rockville, MD: Substance Abuse and Mental Health Services Administration, 2004, p. 2. http://www.kap.samhsa.gov/products/brochures/pdfs/whatistx.pdf.
    2. ^ Ibid, p.4
    3. ^ Substance Abuse and Mental Health Services Administration, Results from the 2011 National Survey on Drug Use and Health: Summary of National Findings, NSDUH Series H-44, HHS Publication No. (SMA) 12-4713. Rockville, MD: Substance Abuse and Mental Health Services Administration, 2012, p. 73. http://www.samhsa.gov/data/NSDUH/2k11Results/NSDUHresults2011.pdf.
    4. ^ SIUC/Core Institute, Executive Summary, Core Alcohol and Drug Survey – Long Form 194, Executive Summary. Carbondale, IL: SIUC/Core Institute, April 13, 2012, p.1. http://core.siu.edu/pdfs/report10.pdf.
    5. ^ Ibid, p.1.
    6. ^ Substance Abuse and Mental Health Services Administration, Results from the 2011 National Survey on Drug Use and Health: Summary of National Findings, NSDUH Series H-44, HHS Publication No. (SMA) 12-4713. Rockville, MD: Substance Abuse and Mental Health Services Administration, 2012, p. 2. http://www.samhsa.gov/data/NSDUH/2k11Results/NSDUHresults2011.pdf.
    7. ^ National Institute of Mental Health, The Numbers Count: Mental Disorders in America. Rockville, MD: National Institute of Mental Health. Retrieved October 4, 2012 from http://www.nimh.nih.gov/health/publications/the-numbers-count-mental-disorders-in-america/index.shtml#KesslerPrevalence.

    8. ^ National Prevention Council, National Prevention Strategy, Priorities: Mental and Emotional Well-being. Washington, DC: U.S. Department of Health and Human Services, Office of the Surgeon General, 2011, p. 48. http://www.healthcare.gov/prevention/nphpphc/strategy/mental-emotional-well-being.pdf.
    9. ^ Guthman, John C., PhD, for the American Psychological Association, College Students Exhibiting More Severe Mental Illness, Study Finds, Pre-existing conditions are contributing factors. Washington, DC: American Psychological Association, August 12, 2010. Retrieved October 4, 2012 from http://www.apa.org/news/press/releases/2010/08/students-mental-illness.aspx.
    10. ^ Substance Abuse and Mental Health Services Administration, About Co-Occurring. Rockville, MD: Substance Abuse and Mental Health Services Administration. Retrieved October 4, 2012 from http://www.samhsa.gov/co-occurring/.
    11. ^ Weitzman, E., Study on Patterns of Drinking and Poor Mental Health in College Finds Depressed Young Women at Highest Risk of Alcohol Abuse. (2005). The Journal of Nervous and Mental Disease. Retrieved October 4, 2012 from http://www.hsph.harvard.edu/cas/Documents/depression-pressRelease/.
    12. ^ Perron, B., Grahovac, I., Uppal, J., et al. (2011). Supporting Students in Recovery on College Campuses: Opportunities for Student Affairs Professionals. Journal of Student Affairs Research and Practice. Journal of Student Affairs Research and Practice. 48(1), p. 52. Retrieved October 4, 2012 from http://journals.naspa.org/jsarp/vol48/iss1/art4/.


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