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Class 12 Biology (India)

Course: Class 12 Biology (India) > Unit 8

Lesson 5: Addiction and Dependence
Science
Class 12 Biology (India)
Human Health and Disease
Addiction and Dependence
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Commonly abused drugs review

Google Classroom
Heroin, cocaine, morphine, barbiturates, nicotine, tobacco
This articles offers an overview of :
  • different categories of drugs,
  • some commonly abused drugs, and
  • the sources and effects of these drugs.

Key terms

TermDefinition
DrugChemical substance that causes a change in the body when consumed
AddictionCondition or disorder which drives compulsive, repetitive actions despite negative consequences
Substance abuseHarmful and extensive misuse of mood-altering chemicals like drugs or alcohol
StimulantSubstances that increase energy and performance
DepressantSubstances that relax or slow down bodily functions

Types of drugs

One way to classify drugs is based on their makeup; chemically similar substances are either synthetically manufactured, or derived from the same natural source. On the other hand, some drugs can have different structures, but similar effects on the human body.
Let's take a look at some common categories of drugs.
CategoryDrugSource
Opioidmorphine, heroinlatex of poppy plant (Papaver somniferum)
Cannabinoidcannabisflower tops, leaves, resin of cannabis plant (Cannabis sativa)
Stimulantcocaineleaves of coca plant (Erythroxylum coca)
Stimulantnicotinetobacco plant (Nicotiana tabacum)

Commonly abused drugs

Drug nameTaken viaEffect
Heroin, smack, diacteylmorphineSnorting/injectionBinds opioid receptors in CNS and GIT; depressant (slows down body functions)
Cannabis, marijuana, hashish, charas, ganjaInhalation/oral ingestionBinds receptors in brain and affects cardiovascular system
Cocaine, coke, crackSnortingStimulates CNS, interferes with dopamine transport; causes euphoria, increased energy, and hallucinations.
NicotineInhalation/oral ingestionStimulates adrenal gland to release adrenaline and noradrenaline; raises blood pressure and heart rate.
Derivatives of Atropa belladona and Datura plants are also known to cause hallucinations.
Let's play detective.
Case 1
The drug-control burueau raids a warehouse to investigate a tip about illegal drug manufacturing on the premises. They find large quantities of plant pods containing a milky latex (see image below).
Further, they find bags of a white, crystalline substance that lab tests later confirm to be diacetylmorphine.
What drug is being manufactured in this warehouse?
Choose 1 answer:

Case 2
A sportsperson is investigated after failing a drug test. When questioned, she admits to occasionally using cannabinoids to relax before big tournament.
Which of the following substances would she have tested positive for?
Choose 1 answer:

Case 3
Authorities break up a party after receiving complaints of excessive noise. They discover a room in which some people are snorting a white powder, and note that several attendees seem abnormally energetic. A few people seemed to be hallucinating - talking to themselves or to the air.
What drug did the party goers consume?
Choose 1 answer:

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