This presentation covers the nature and features of drug dependence. It also gives coverage to different psychological or biological models of drug addiction.

1. Aleem Ashraf
Department of Psychology
University of Sindh, Jamshoro.
Features and Models of Drug Abuse

2. Contents
1. Introduction to Drug Abuse and Dependence
2. Features of Drug Abuse and Dependence
3. Models of Drug Abuse and Dependence
4. Comprehensive Model of Drug Abuse and Dependence
5. Reference

3. Introduction

4. Historical trends
 Natural drugs from plants have always been available to
people.
 In U.S, alcohol and caffeine were widely used 200 years ago.
 Chewing tobacco was becoming popular (no cigarettes yet)
 Opium was available as a pain killer.
 No drug control laws.

5.  Benjamin Rush’s Alcohol temperance movement
 Identified physiological effects of alcohol and moral and
criminal consequences
 Advances in chemistry enhanced the potency of natural
drugs
 Opium to morphine, coca to cocaine
 Hypodermic syringe’s invention also enhanced the
immediate drug effect
 Soldier syndrome (opiate addiction) became common during
civil war

6.  Cocaine was freely available in tonics
 Heroin was created by Bayer to treat soldier’s disease
 It was a common ingredient of cough syrups
 Easy availability increased drug dependence
 Medicalization of drug addiction in 1950s sees addicts as
medical patients

7. Features of Drug
Abuse and
Dependence

8. Drug addiction is a chronic, relapsing
behavioral disorder
 First: It causes physical dependence. Body builds tolerance
for the drug requiring addict to take more and more to get
the same effect. Followed by unpleasant withdrawal
symptoms
 Second: Emphasis on behavior because of compulsive nature
of addiction i.e. cravings.
 It is a chronic relapsing disorder with periods of remissions
and relapsing

9.  Third: Drug use persists despite serious harmful
consequences
 DSM-IVTR distinguished between drug abuse and drug
dependence
 DSM-5 has removed this distinction and only calls it a drug
use disorder

10. Progressions in drug use
 First: An individual starts from a legal substance and
gradually progresses towards illegal ones
 Second: An individual changes the amount, pattern and
consequences of drug use according to their health effects
(continuum of drug use)
 Support for this view from a longitudinal study of opiod
(heroin) addicts (Maddux & Desmond, 1981).

13. Which drugs are most addictive?
 Two addiction researchers Dr. Jack Henningfield and Dr. Neil
Benowitz gave ratings to substances of abuse on five
categories:
 Presence and severity of withdrawal symptoms
 Strength of the reinforcing effects
 Degree of tolerance produced
 Degree of dependence produced
 Degree of intoxication

14. Substance Withdr
awal
Reinforc
ement
Toleranc
e
Depende
nce
Intoxicati
on
Nicotine 3 4 2 1 5
Heroin 2 2 1 2 2
Cocaine 4 1 4 3 3
Alcohol 1 3 3 4 1
Caffeine 5 6 5 5 6
Marijuana 6 5 6 6 4
1 = most serious, 6 = least serious

15. 1. Heroin was the most problematic substance (mean rating
1.9)
2. Alcohol (mean rating 2.5)
3. Cocaine (mean rating 2.65)
4. Nicotine (mean rating 3.35)
5. Caffeine (5.0)
6. Marijuana (5.4)
Note:The long term effects of these drugs were not considered
in these ratings.

16. Models of Drug Abuse
and Dependence
1. Physical dependence model
2. Positive reinforcement model
3. Disease/medical model

17. Physical dependence model
 Repeated drug use makes an individual physically dependent
on drug
 Body builds tolerance requiring more and more drug to get
the same effect
 Followed by unpleasant withdrawal symptoms (abstinence
syndrome)
 Withdrawal symptoms work as negative reinforcement

18.  Withdrawal symptoms can be triggered by the environment
even in the absence of physical dependence because of
classical conditioning (Wikler, 1980).
 Drug related cues can generate a craving for the drug as
studied by Anna Rose Childress and Charles O’Brien
 Cocaine addicts (not controls) felt a strong craving for
cocaine while watching a cocaine related video

19. Limitations of dependence model
 Why do people become dependent on non addicting drugs
such as cocaine?
 It doesn’t tell us why an individual starts taking a drug in the
first place.
 Why does an individual relapse after the physical dependence
(detoxification) is no longer there?
 Wikler responded “classical conditioning” but that’s a
psychological reason not physical

20. Positive reinforcement model
 The rewarding effects of the drug such as euphoria, increased
alertness, anxiety reduction work as the positive
reinforcement to maintain drug use
 Animal studies also support this hypothesis. Rats self
administer drugs after they have learnt to obtain the drug
 Animals can go to extremes and kill themselves with
overdose but researchers limit their study for few hours

21. Physiology of reinforcement
 Drugs of abuse such as cocaine and marijuana hijack brain’s
reward system called Dopaminergic mesolimbic system
 They block the reuptake of dopamine (pleasure
neurotransmitter) from the synapses
 Which desensitizes the body’s natural production of it making
it difficult to experience pleasure

22. Limitations of positive reinforcement
model
 Why people continue to take drugs despite the diminishing
drug effect?
 Why negative consequences of drug use such as
relationship, financial, social problems do not inhibit the drug
use?
 Because of temporal relationship between action and
reinforcement
 Why do people stop using drug after the initial use despite
reinforcing effects?

23.  The drug itself produces many undesirable effects.Why do
people still take them despite the absence of positive
reinforcement?

24. The disease/medical model of addiction
 This is the most widely accepted model of addiction today
 Mainly developed for alcoholics. Benjamin Rush, the first to
consider alcoholism a medical disease
 Two types of disease models:
 Susceptibility model
 Exposure model

25. Susceptibility model:
 Jellinek’s model sees people to have born with a
to become addicts
 When someone uses a drug for the first time, he/she loses
control because of an inherited susceptibility
 Genes play an important role in behavior and drug use is
exception

26. Exposure model:
 Chronic drug use leads to alterations in the brain that
out of control drug use
 Alan Leshner’s (1997) article “Addiction Is a Brain Disease,
and It Matters”
 Addiction modifies brain structure that influence its
 An imaginary switch in the brain stops working that’s why
person loses control

27. Limitations of disease model
 Removed the stigma from addicts (previously addicts were
seen morally ill)
 Reduced the personal guilt from the addict which helps in
recovery
 Disease requires medical tests and are known to have a cause
that can be seen in a report
 Disease reports come down as positive or negative

28.  Blood or liver tests can only show the presence of drug use
but the evidence of medical test is the consequence of drug
use, not the cause!
 If it’s a disease, there is still no tests to trace its causes
 It’s only diagnosed through signs and symptoms
 Same is true for all psychiatric disorders such as depression,
anxiety, schizophrenia etc.
 There is no sharp distinction between who is diagnosed
addict and who is not. It lies on the continuum

29.  This model ignores other factors that contribute to addiction
such as learning, cognition and environment

30. Comprehensive Model
of Drug Abuse &
Dependence

31.  A comprehensive model should explain addiction from all
three perspectives:
 Biological: Genes, temperament, physique etc.
 Psychological: Cognition, learning
 Sociological: Culture, peers, economic condition etc.
 It can be termed as biopsychosocial model

32. Experimental substance use
 The experimental substance use that starts from teenage is
influenced by three types of factors which have three levels each
 Three types of factors:
 Social/interpersonal
 Cultural/attitudinal
 Intrapersonal
 Levels include: Proximal, Distal & Ultimate

33. Level Social/interpersonal Cultural/attitudinal Intrapersonal
Proximal Peer pressure to use
substance
Belief that such use is
normal
Belief that benefits of
substance are greater
than costs
Belief that one has
capability to control
use
Distal Stronger attachment
peers than family
Positive attitude of peers
towards drugs
Social alienation;
rejection of social
short term gratification,
rebelliousness
Low self esteem; poor
social, academic or
coping skills, stress,
anxiety..
Ultimate Lack of parental support,
reinforcement or
supervision; negative
evaluations from
familial stress, parental
divorce
Easy availability of
high crime rate,
inadequate education,
unemployment
Genetic susceptibility,
personality traits i.e.
impulsivity, risk-
taking, emotional
instability,
aggressiveness

34. Development & maintenance
1. Drug related factors
2. Risk factors
3. Protective factors

35. Drug related factors
 Positive reinforcing factors of drugs such as euphoria, relief
from withdrawal symptoms, relief from anxiety and
functional enhancement i.e. increased alertness

36. Risk factors
 Drug addiction also depends on the amount of stress and
stress management skills
 Stress coping is taught to the addicts for controlling drug use
 Presence of other psychological disorders (comorbidity)
 Comorbidity with drug dependence is more in females than
males (Zilberman et al, 2003)
 Substance use disorder is a primary diagnosis in men

37. Personality related pathways to addiction
 Verhuel and van den Brink (2000) proposed three pathways
to addiction:
No. Pathway Description
1 Behavioral
disinhibition
Impulsivity, antisociality,
unconventionality, aggressiveness, low
harm avoidance
2 Stress reduction Stress reactivity, anxiety, depression,
neuroticism
3 Reward sensitivity Sensation seeking, reward seeking,
extraversion, gregariousness

38.  Familial risk factors: Alcoholic parents -> alcoholic children
(modeling)
 Other purposes that serve addicts:
 Social facilitation
 Escape from daily responsibilities
 Group solidarity within an ethnic group
 Genes also play a modulatory role i.e. altering the receptors’
sensitivity to neurotransmitters

39. Protective factors
 Absence of all the factors mentioned so far. For example:
 Absence of other psychiatric disorder
 Absence of problematic personality traits
 Stable family without substance use
 Not belonging to drug promoting ethnic group etc.

40. Protective factors after abstinence
 There is always a chance of a relapse after remission from
drug use
 Positive life changes like marriage, spiritual/religious
experience
 Negative consequences of drug use i.e. health problem,
financial problem, loss of job, social pressure etc.
 Moving to new area, new social relationships, employment,
substitute activities like exercise etc.

41. Reference
Meyer, J. S., & Quenzer, L. F. (2005). Psychopharmacology:
Drugs, the brain, and behavior. Sunderland, Mass: Sinauer

42. Thank you 