Download - Drug Abuse, Dependence & Addiction
DRUG ABUSE,DEPENDENCE& ADDICTION
Aleem AshrafDepartment of Psychology
University of Sindh, Jamshoro.
Features and Models of Drug Abuse
Contents1. Introduction to Drug Abuse and Dependence2. Features of Drug Abuse and Dependence3. Models of Drug Abuse and Dependence4. Comprehensive Model of Drug Abuse and
Dependence5. Reference
Introduction
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.
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
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
Features of Drug Abuse and
Dependence
Drug addiction is a chronic, relapsing behavioral disorderFirst: 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
Third: Drug use persists despite serious harmful consequences
DSM-IV TR distinguished between drug abuse and drug dependence
DSM-5 has removed this distinction and only calls it a drug use disorder
Progressions in drug useFirst: An individual starts from a legal substance
and gradually progresses towards illegal onesSecond: 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).
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
Substance
Withdraw
al
Reinforceme
nt
Tolerance
Dependence
Intoxication
Nicotine 3 4 2 1 5Heroin 2 2 1 2 2Cocaine 4 1 4 3 3Alcohol 1 3 3 4 1Caffeine 5 6 5 5 6Marijuana
6 5 6 6 41 = most serious, 6 = least serious
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.
Models of Drug Abuse and
Dependence1. Physical dependence model2. Positive reinforcement model3. Disease/medical model
Physical dependence modelRepeated drug use makes an individual physically
dependent on drugBody builds tolerance requiring more and more
drug to get the same effectFollowed by unpleasant withdrawal symptoms
(abstinence syndrome)Withdrawal symptoms work as negative
reinforcement
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
Limitations of dependence modelWhy 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
Positive reinforcement modelThe 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
Physiology of reinforcementDrugs 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
Limitations of positive reinforcement modelWhy 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?
The drug itself produces many undesirable effects. Why do people still take them despite the absence of positive reinforcement?
The disease/medical model of addictionThis is the most widely accepted model of
addiction todayMainly developed for alcoholics. Benjamin Rush,
the first to consider alcoholism a medical diseaseTwo types of disease models:
Susceptibility model Exposure model
Susceptibility model:Jellinek’s model sees people to have born with a
susceptibility to become addictsWhen 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 no exception
Exposure model:Chronic drug use leads to alterations in the brain
that result in out of control drug useAlan Leshner’s (1997) article “Addiction Is a Brain
Disease, and It Matters”Addiction modifies brain structure that influence
its functionAn imaginary switch in the brain stops working
that’s why a person loses control
Limitations of disease modelRemoved the stigma from addicts (previously
addicts were seen morally ill)Reduced the personal guilt from the addict which
helps in recoveryDisease requires medical tests and are known to
have a cause that can be seen in a reportDisease reports come down as positive or
negative
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 causesIt’s only diagnosed through signs and symptomsSame 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
This model ignores other factors that contribute to addiction such as learning, cognition and environment
Comprehensive Model of Drug
Abuse & Dependence
A comprehensive model should explain addiction from all three perspectives:
Biological: Genes, temperament, physique etc.Psychological: Cognition, learningSociological: Culture, peers, economic condition
etc.It can be termed as biopsychosocial model
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
Level Social/interpersonal
Cultural/attitudinal
Intrapersonal
Proximal Peer pressure to use substanceBelief that such use is normal
Belief that benefits of substance are greater than costs
Belief that one has the capability to control use
Distal Stronger attachment with peers than familyPositive attitude of peers towards drugs
Social alienation; rejection of social values, 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 parents; familial stress, parental divorce
Easy availability of drugs, high crime rate, inadequate education, unemployment
Genetic susceptibility, personality traits i.e. impulsivity, risk-taking, emotional instability, aggressiveness
Development & maintenance1. Drug related factors2. Risk factors3. Protective factors
Drug related factorsPositive reinforcing factors of drugs such as
euphoria, relief from withdrawal symptoms, relief from anxiety and functional enhancement i.e. increased alertness
Risk factorsDrug addiction also depends on the amount of stress and
stress management skillsStress coping is taught to the addicts for controlling drug
usePresence 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
Personality related pathways to addictionVerhuel and van den Brink (2000) proposed three
pathways to addiction:No. Pathway Description1 Behavioral
disinhibitionImpulsivity, antisociality, unconventionality, aggressiveness, low harm avoidance
2 Stress reduction Stress reactivity, anxiety, depression, neuroticism
3 Reward sensitivity
Sensation seeking, reward seeking, extraversion, gregariousness
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
Protective factorsAbsence of all the factors mentioned so far. For
example:Absence of other psychiatric disorderAbsence of problematic personality traitsStable family without substance useNot belonging to drug promoting ethnic group etc.
Protective factors after abstinenceThere is always a chance of a relapse after remission
from drug usePositive life changes like marriage, spiritual/religious
experienceNegative 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.
ReferenceMeyer, J. S., & Quenzer, L. F.
(2005). Psychopharmacology: Drugs, the brain, and behavior. Sunderland, Mass: Sinauer Associates, Publishers.
Thank you