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