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Test Your Science Literacy About Cannabis

20 questions on medical and recreational cannabis and their impact on the brain.

Key points

  • Science literacy about cannabis is sadly lacking among both the general public and professionals.
  • The science of cannabis is more than the botany of the plant. It also involves the neuroscience of the brain's natural cannabinoid chemistry.
  • These 20 questions can test your science literacy about cannabis.

Science literacy about cannabis is sadly lacking in both the general public and health professionals. This is not because the public lacks curiosity about the topic, but rather because most people get information about cannabis from friends, the Internet, popular websites, and personal experience — which can be echo chambers filled with anecdotes, opinions, exaggerations, outright misinformation, and a smattering of facts.

The cannabis industry opposes warning labels, and the government is prevented by the first amendment from mandating dispensaries provide objective information. Doctors are not well informed about cannabis because as recently as five years ago only 9% of medical schools taught students anything about the use of medical cannabis.[1] These combined influences increase the difficulty of making well-informed, science-based decisions about the proper medical use of cannabis and how to use recreational cannabis safely.

How much do you know about both the botany of cannabis and the neuroscience of its interaction with the brain? Answer the following 20 questions before looking at the answers and explanations below. Some questions may seem hard, but all are relevant to a solid understanding of how our brain’s natural cannabinoid chemistry is impacted by THC and CBD. Good luck!

1. The main psychoactive ingredients in cannabis come from:

a. Female plants

b. Male plants

c. Both

2. The most common variety of cannabis available is:

a. Cannabis Indica

b. Cannabis Sativa

c. Hybridized Indica and Sativa

3. The main psychoactive ingredient in cannabis is:

a. Delta-8-THC

b. Delta-9-THC

c. Cannabidiol - CBD

d. CBG

e. Terpenes

4. CBD oil typically comes from:

a. Marijuana

b. Cannabis Indica

c. Industrial Hemp

d. Laboratory synthesis

5. CBD does the following except:

a. Activate cannabinoid receptors

b. Activate serotonin receptors

c. Modify THC’s effect by altering the shape of cannabinoid receptors

6. A single dose of cannabis does the following for most people except:

a. Decrease short-term memory

b. Increase sense of connectedness

c. Diminish sense of stress

d. Speed up sense of time

e. Alter the texture of experience

f. Increase appetite

7. Anandamide is an:

a. Endocannabinoid neurotransmitter

b. Endorphin neurotransmitter

c. A form of THC

d. The brain’s natural CBD

e. =

8. The following are all part of the endocannabinoid system except:

a. CB1 receptors

b. Anandamide

c. 2-AG

d. The amygdala

e. CB2 receptors

9. The basic function of the endocannabinoid system is to:

a. Respond to THC

b. Reduce anxiety

c. Regulate brain neurotransmitter systems

d. Reduce pain

10. True or false? Our endocannabinoid system developed soon after cannabis evolved.

a. True

b. False

11. Which is not true?

a. Downregulation refers to a reduction in cannabinoid receptors

b. CBD downregulates cannabinoid receptors

c. THC downregulates cannabinoid receptors

d. Increased anandamide levels do not downregulate cannabinoid receptors

12. All of the following are true about downregulation of cannabinoid receptors except:

a. Downregulation begins with a single use of cannabis

b. Daily cannabis reduces CB1 receptors by 20-60% in different areas of the brain

c. Near daily cannabis use reduces cannabinoid receptors 20% in the frontal lobes

d. Downregulation of cannabinoid receptors is usually permanent

13. What percent of adult-onset cannabis users become addicted?

a. 0%

b. 3-4%

c. 9-10%

d. 15-16%

14. High concentrations of THC increase schizophrenia-like psychosis:

a. Not at all

b. Twofold

c. Threefold

d. Fourfold

e. Fivefold

15. Medical cannabis and recreational cannabis impact the brain differently.

a. True

b. False

16. Some childhood forms of epilepsy have been successfully treated with:

a. THC

b. CBD

c. A balanced mixture of THC and CBD

17. The Institute of Medicine finds conclusive or substantial evidence cannabis benefits all the following except:

a. Depression

b. Nausea and vomiting caused by chemotherapy

c. Spasticity from multiple sclerosis

d. Fibromyalgia

e. Chronic pain in adults

f. Obstructive sleep apnea

18. A study of cannabis and cognition in Dunedin, New Zealand showed:

a. Cannabis reduces IQ by 8 points in long-term cannabis users

b. Daily cannabis use decreases fertility by 16%

c. Reduced IQ occurs only in long-term cannabis use with adolescent onset

d. Cannabis use has no impact on IQ

19. When heavy users of cannabis reduce or stop using, they may experience the following except:

a. Anxiety/Irritability

b. Physical Restlessness

c. Nightmares

d. Boredom

20. Cannabis is potentially addictive.

a. True

b. False



1. A - Only female plants are psychoactive.

2. C - Most cannabis today is highly hybridized and selectively bred to increase THC levels.

3. B - Delta-9 THC is the main psychoactive ingredient in cannabis.

4. C - Industrial hemp contains minimal THC and 15% CBD.

5. A - See the post 5 Things CBD Can Do For You.

6. D - Cannabis slows the perception of time.

7. A - Anandamide is the first endogenous cannabinoid (endocannabinoid) found in the brain.

8. D - The endocannabinoid system contains neurotransmitters, receptors, and enzymes to synthesize and break them down. See The Brain’s Critically Important Natural Cannabinoid System.

9. C - The endocannabinoid system provides negative feedback on other neurotransmitters to keep them in balance.

10. B - False. The endocannabinoid system evolved eons before cannabis.

11. B - Only THC is strong enough to reduce cannabinoid receptors. See How Cannabis Defeats Itself When Used Too Frequently.

12. D - CB1 receptors that are down regulated 20% in the frontal lobes recover in a month.

13. C - 9-10% of adult-onset cannabis users become addicted. Adolescent-onset users are at much greater risk of addiction. See 2 Sources of Cannabis Addiction.

14. D and E - High THC raises the risk of psychosis four to fivefold, see The Complex Link Between Cannabis Use and Psychosis.

15. B - False. The brain does not know the difference because there is no difference between medical and recreational cannabis products.

16. B - Severe childhood epilepsy benefits from Charlotte’s Web, a cannabis variety high in CBD, and Epidiolex an FDA-approved medication. See 5 Things CBD Can Do For You.

17. A - See The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research, The National Academies Press, 2017.

18. C - IQ is reduced only with early onset and persistent cannabis use. See Does Cannabis Decrease IQ?

19. C - Insomnia is more likely, see 5 Signs of Using Cannabis Too Frequently.

20. A - True, see 2 Sources of Cannabis Addiction.


How did you do? Full explanations and underlying research can be found in From Bud to Brain and/or Marijuana on My Mind. Once you have acquainted yourself with a basic scientific understanding of cannabis and how it interacts with your brain’s natural cannabinoid chemistry, you will be better equipped to use cannabis products safely and effectively.


1. A. B. Evanoff, et al. Physicians-in-training Are Not Prepared to Prescribe Medical Marijuana. Drug and
Alcohol Dependence, 2017; 180: 151–5. (Published online September 4, 2017.)

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