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Department of Health Services

Myths and Facts About Marijuana Use


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MYTH: Marijuana is okay for some youth

FACTS: Research strongly suggests that marijuana use during adolescence and early adulthood can damage the part of the brain associated with learning and memory.1

Regular marijuana use during adolescence can lead to reduced IQ scores, poorer school performance,2 and higher school dropout rates.3

MYTH: Marijuana isn’t addictive

FACTS: From 2012-2015, marijuana has remained the most common primary drug of abuse among 12-18 year olds seeking publicly funded treatment services in Sonoma County.4

In FY 2014-2015, of the 344 youth entering treatment in Sonoma County, 244 or 71% sought treatment for marijuana addiction.5

Chronic marijuana use can lead to addiction. Research shows that approximately 9 percent, or about 1 in 11, of those who use marijuana will become addicted. This goes up to 17 percent in those who start using while young (in their teens) and increases to 25-50 percent of daily users.6

Long-term marijuana users trying to quit report various withdrawal symptoms, including irritability, sleeplessness, decreased appetite, anxiety, and drug craving.7

MYTH: Marijuana is safe to use during pregnancy and breastfeeding

FACTS: Marijuana use in pregnancy may affect the baby’s brain development and when the child reaches school age, it may have problems with attention, behavior, memory, delayed reading skills, and depression.8

Using marijuana during pregnancy is as serious as cigarette smoking or alcohol consumption. Marijuana is not recommended, even for medicinal purposes— during preconception, pregnancy, or lactation. There is no safe level for marijuana use in pregnancy.9 10

Research strongly suggests that use of marijuana during pregnancy can lead to low birth weight, premature babies, small full-term babies, and hospital stays in the special newborn care nursery.11

Breastfed infants are exposed at unhealthy levels. The active ingredient in marijuana, THC, builds up in the breast milk of marijuana-using mothers, and when nursing, comes out in their breast milk. With chronic, heavy use, THC levels can be 8 times higher in breast milk than in the mother’s blood.12

MYTH: Marijuana has minimal impact on driving, road safety and crime

FACTS: Marijuana significantly impairs judgment, motor coordination, and reaction time. Studies have found a direct relationship between the concentration of marijuana (THC) in the blood and driving ability. The risk of being involved in an accident doubles after marijuana use.13

Accident-involved drivers with THC in their blood, particularly higher levels, are three to seven times more likely to be responsible for the accident than drivers who had not used drugs or alcohol.14

The risk associated with marijuana in combination with alcohol appears to be greater than that for either drug by itself.15

MYTH: Marijuana helps one’s mood and promotes mental health

FACTS: Like alcohol, marijuana and associated THC-containing products are intoxicants and can contribute to impaired judgment and increased susceptibility to mental health problems, including depression, insomnia and paranoid delusions.16

There is a significant risk of relapse or worsening of symptoms for individuals with psychotic disorders.17

Regular marijuana use is correlated with an increased risk and/or worsening of the symptoms for individuals with anxiety, depression and psychotic illnesses.18

MYTH: Secondhand marijuana smoke is safe

FACTS: Smoking marijuana clearly damages the human lung, causing chronic bronchitis and injury to the cell linings of the large airways.19

Second hand smoke from burning marijuana has been shown to contain many of the same toxins, irritants and carcinogens as tobacco and wood burning smoke.20

In 2009, California added marijuana smoke to the list of chemicals known to cause cancer and reproductive toxicity under the Safe Drinking Water and Toxic Enforcement Act (Proposition 65). At least 33 individual constituents were identified in both marijuana smoke and tobacco smoke that contain 65 carcinogens.21

Infants who are exposed to second-hand marijuana smoke are at risk of sudden infant death syndrome (aka SIDS).22

Resources & Helpful Links

Sonoma County Department of Health Services Marijuana Information Page

Partnership for Drug-Free Kids

National Institute on Drug Abuse (NIDA)


1 Ventura County. (2015) “Marijuana and Your Kid’s Brain.” Marijuana in Ventura County: A Gateway for Discussion, © 2014, Ventura County Behavioral Health. http:// article/E413A9/marijuana-and-your-kids-brain-video

2 Fergusson, D.M. et al. (2010). Cannabis and Educational Achievement: Findings from Three Australian Cohort Studies. Drug and Alcohol Dependence, Vol 110, Issue 3, August 2010.

3 Meier M.H., Caspi A., Ambler A., et al. Persistent cannabis users show neuropsychological decline from childhood to midlife. Proc Natl Acad Sci USA. 2012;109:E2657-2664

4 Sonoma County Dept. of Health Services. Sonoma Web Infrastructure for Treatment Services (SWITS) data. SWITS report period: 7.1.2012 to 6.30.2015. Accessed December, 2015.

5 Ibid

6 National Institute on Drug Abuse. National Institutes of Health. (2015). Marijuana Facts for Teens.

7 National Institute on Drug Abuse. National Institutes of Health. (2015). Research Report Series: Marijuana.

8 Goldschmidt, L., et al. School achievement in 14-year old youths prenatally exposed to marijuana. Neurotoxicol Teratol (2011). Doi: 10:1016/

9 The American College of Obstetricians and Gynecologists, Committee on Obstetric Practice. Marijuana use during pregnancy and lactation. Committee Opinion, November 637, July 2015.

10 Jacques, SC., et al. Cannabis, the pregnant woman and her child: Weeding out the myths. Journal of Perinatology (2014) 34, 417-424.

11 Hayatbakhsh, MR., (2012). Birth outcomes associated with cannabis use before and during pregnancy. International Pediatric Research Foundation, Inc. Volume 71, Number 2, February 2012.

12 Behnke MD, M., et al (2013). Perinatal substance abuse: shortand long-term effects on the exposed fetus. American Academy of Pediatrics, Pediatrics, Volume 131, Number 3, March 2013.

13 National Institute on Drug Abuse. National Institutes of Health. (2015). Research Report Series: Marijuana.

14 Ibid

15 Ibid

16 National Alliance on Mental Illness (2013) Marijuana and Mental Illness Fact Sheet. Duckworth, K., Freedman, J., reviewers. Minds/Smoking_Cessation/Marijuana_and_Mental_Illness.htm.

17 D’Souza, D. R. (2015). Medical marijuana: Is the cart before the horse? Journal of the American Medical Association, 2015;313(24):2431-2432. doi:10.1001/jama.2015.6407.

18 Hill, K. (2015). Medical marijuana for treatment of chronic pain and other medical and psychiatric problems: A clinical review. Journal of the American Medical Association, 313(24), 2474-2483.

19 Retrieved from health-effects/marijuana-lung-health.html

20 Ibid

21 Retrieved from pdf_zip/FinalMJsmokeHID.pdf

22 Reece-Stremtan, S., et al. The Academy of Breastfeeding Medicine Clinical Protocol #21: Guidelines for Breastfeeding and Substance Use or Substance Use Disorder, Revised 2015. Breastfeeding Medicine, Volume 10, Number 3, 2015.