DEFINITIONS• DRUG USE
• TAKING A PSYCHOACTIVE SUBSTANCE FOR NON-MEDICAL PURPOSES, OUT
OF CURIOSITY
• DRUG ABUSE
• DRUG USE THAT LEADS TO PROBLEMS (E.G. LOSS OF EFFECTIVENESS IN
SOCIETY; BEHAVIORAL PSYCHOPATHOLOGY, CRIMINAL ACTS)
• DRUG DEPENDENCE
• A MALADAPTIVE PATTERN OF DRUG USE LEADING TO CLINICALLY-
SIGNIFICANT IMPAIRMENT OR DISTRESS, ASSOCIATED WITH DIFFICULTY IN
CONTROLLING DRUG-TAKING BEHAVIOR, WITHDRAWAL, AND TOLERANCE
• THE STATE OF NEEDING A DRUG TO FUNCTION WITHIN ‘NORMAL LIMITS’
NATURE OF ADDICTION - A CONTINUUM OF USE
Loss of control
DSM-IV CRITERIA FOR SUBSTANCE DEPENDENCE
• TOLERANCE
• WITHDRAWAL
• SUBSTANCE TAKEN IN LARGER AMOUNTS OR OVER A LONGER PERIOD THAN INTENDED
• PERSISTENT DESIRE OR UNSUCCESSFUL EFFORTS TO CUT DOWN OR CONTROL SUBSTANCE USE
• GREAT DEAL OF TIME SPENT IN ACTIVITIES NECESSARY TO OBTAIN SUBSTANCE, USE SUBSTANCE
(E.G., CHAIN SMOKING), OR RECOVER FROM EFFECTS
• IMPORTANT SOCIAL, OCCUPATIONAL, OR RECREATIONAL ACTIVITIES GIVEN UP OR REDUCED
BECAUSE OF SUBSTANCE USE
• SUBSTANCE USE CONTINUED DESPITE KNOWLEDGE OF PERSISTENT OR RECURRENT PHYSICAL OR
PSYCHOLOGICAL PROBLEM LIKELY TO HAVE BEEN CAUSED OR EXACERBATED BY SUBSTANCE
A maladaptive pattern of substance use, leading to clinically significant impairment or distress, as
manifested by three (or more) of the following, occurring at any time in the same 12 month period:
PHYSICAL VS. PSYCHOLOGICAL DEPENDENCE
• PHYSICAL DEPENDENCE
• WITHDRAWAL SYMPTOMS IN THE ABSENCE OF THE DRUG
• TOLERANCE TO ITS EFFECTS WITH REPEATED USE
• PSYCHOLOGICAL DEPENDENCE
• “A RELATIVELY EXTREME, PATHOLOGICAL STATE IN WHICH OBTAINING,
TAKING, AND RECOVERING FROM A DRUG REPRESENTS A LOSS OF
BEHAVIORAL CONTROL OVER DRUG TAKING WHICH OCCURS AT THE
EXPENSE OF MOST OTHER ACTIVITIES AND DESPITE ADVERSE
CONSEQUENCES” (ALTMAN ET AL)
• “A SITUATION WHERE DRUG PROCUREMENT AND ADMINISTRATION APPEAR
TO GOVERN THE ORGANISM’S BEHAVIOR, AND WHERE THE DRUG SEEMS TO
DOMINATE THE ORGANISM’S MOTIVATIONAL HIERARCHY” (BOZARTH)
CLASSIC MODELS OF ADDICTION
Model Emphasized Causes Example Interventions
Moral Personal responsibility; self-
control
Moral suasion; social/legal
sanctions
Spiritual Spiritual defect Prayer; 12-step faith-based
treatment (e.g. AA)
Temperance Drugs Control of supply; calls for
abstinence
Educational Ignorance Education
Conditioning Classical/operant
conditioning
Counterconditioning;
extinction
CLASSIC MODELS OF ADDICTION CONTINUED
Model Emphasized Causes Example Interventions
Biological Heredity; brain physiology;
self-medication
Risk identification; calls for
abstinence; medical treatment
Psycho-
dynamic
Personality; defense
mechanisms
Psychoanalysis
Family
Dynamics
Family dysfunction Family therapy
Social
Learning
Modeling; expectancies Positive role models; rational
restructuring of expectancies
Sociocultural Environmental; cultural;
economic
Social policy; social services
PHYSICAL DEPENDENCE OR WITHDRAWAL MODEL(NEGATIVE REINFORCEMENT)
• SOME DRUGS PRODUCE PHYSICAL DEPENDENCE AND WITHDRAWAL
SYMPTOMS UPON CESSATION OF DRUG-TAKING.
• WITHDRAWAL SYMPTOMS ARE PRODUCED BY THE BODY IN ORDER TO
COMPENSATE FOR THE UNUSUAL EFFECTS OF THE DRUG.
• WITHDRAWAL SYMPTOMS ARE GENERALLY THE OPPOSITE OF THE EFFECT
PRODUCED BY THE DRUG.
• ADDICTS CONTINUE TO USE DRUGS IN ORDER TO AVOID
WITHDRAWAL.
• OVER TIME, DRUGS NO LONGER HAVE THE SAME REWARDING
EFFECTS - THEY MERELY ALLOW THE PERSON TO FEEL “NORMAL.”
INADEQUACIES OF WITHDRAWAL MODEL
• NOT ALL ABUSED DRUGS GENERATE WITHDRAWAL SYMPTOMS (COCAINE,
AMPHETAMINE).
• DIFFERENT DRUGS PRODUCE DIFFERENT WITHDRAWAL SYMPTOMS WITH
DIFFERENT NEURAL BASES.
• ONCE DEPENDENT YOU SHOULD CONTINUE TAKING DRUG, BUT PEOPLE
SPONTANEOUSLY STOP.
• ONCE DRUG-ABSTINENT, USERS SHOULD NOT RELAPSE SINCE MOTIVATION
HAS DISAPPEARED, BUT THEY DO.
• NO EXPLANATION AS TO WHY PEOPLE TAKE DRUGS IN THE FIRST PLACE.
POSITIVE INCENTIVE (HEDONIC) MODELS(POSITIVE REINFORCEMENT)
• DRUGS PRODUCE PLEASURE - A “HIGH.”
• SOME DRUGS PROVIDE INDIRECT POSITIVE INCENTIVE - THEY
DISINHIBIT BEHAVIOR THAT IS NORMALLY SUPPRESSED (E.G., ALCOHOL
AND SOCIAL SKILLS).
• MOST DRUGS OF ABUSE STIMULATE THE BRAIN’S REWARD CIRCUITS.
• ALL KNOWN DRUGS OF ABUSE STIMULATE RELEASE OF
DA/OPIOIDS IN THE NUCLEUS ACCUMBENCY
• ANIMALS WILL WORK TO MICRO-INJECT DRUGS OF ABUSE AND
ELECTRICALLY STIMULATE THE SAME PARTS OF THE BRAIN
• NORMAL REWARDS (FOOD, DRINK, SEX) ALSO STIMULATE DA
RELEASE
ANIMAL MODELS OF REINFORCEMENT (CONT.)
• SELF-ADMINISTRATION
• ANIMALS WORK FOR REINFORCING
DRUGS (IV, ORAL, INHALANT)
• SCHEDULES OF REINFORCEMENT
(FIXED, PROGRESSIVE RATIO)
DA RELEASE FOLLOWING VTA STIMULATION
DRUGS THAT ARE AND ARE NOT SELF ADMINISTERED BY ANIMALS
• ALCOHOL
• AMPHETAMINE
• BARBITURATES
• CAFFEINE
• COCAINE
• NICOTINE
• OPIATES
• PROCAINE (N.A. BY HUMANS)
• PCP
• THC
• IMIPRAMINE
• MESCALINE (ABUSED BY HUMANS)
• PHENOTHIAZINES
• SCOPOLAMINE
DRUG DEPENDENCE AMONG EVER-USERS
0 10 20 30 40
Marihuana
Stimulants
Alcohol
Cocaine
Heroin
Tobacco
% Dependent
Addiction treatment hospital
OPPONENT PROCESS MODEL(SOLOMON, 1977)
• DRUG-USE INITIALLY MOTIVATED BY POSITIVE REINFORCEMENT
• OVER TIME, TOLERANCE TO REWARDING EFFECTS, BUT ABSTINENCE LEADS TO
WITHDRAWAL
• DRUG USE ULTIMATELY MAINTAINED BY NEGATIVE REINFORCEMENT
CURRENT TRADITIONAL VIEW(BASED ON OPPONENT PROCESS MODEL)
• INITIATION OF DRUG TAKING IS PRIMARILY DRIVEN BY ANTICIPATED PLEASURE
(FACILITATED BY PEER PRESSURE, SOCIAL FACILITATION, CURIOSITY).
• FOR MOST DRUGS, PLEASURE BECOMES PRIMARY MOTIVATOR AND DRUG CRAVING
BECOMES CUED BY DRUG RELATED STIMULI.
• FOR SOME DRUGS (E.G., ALCOHOL, COCAINE, HEROIN) PLEASURE IS ENHANCED BY
REVERSING UNPLEASANT ASPECTS OF NORMAL LIFE.
• FOR SOME DRUGS (E.G., NICOTINE, CAFFEINE, HEROIN, ALCOHOL), DRUG-TAKING
LEADS TO DEPENDENCE AND WITHDRAWAL WHICH ADDS ADDITIONAL MOTIVATION TO
CONTINUE DRUG-TAKING HABIT AND MAKES “GIVING UP” DIFFICULT.
• THIS WITHDRAWAL STATE CAN ALSO BE ASSOCIATED WITH ENVIRONMENTAL CUES,
AND INCREASES THE TENDENCY FOR RELAPSE.
LIMITATIONS OF OPPONENT PROCESS MODELS
• DRUG WITHDRAWAL IS MUCH LESS POWERFUL AT MOTIVATING
DRUG-TAKING BEHAVIOR
• STRESS SEEMS TO BE MORE POWERFUL
• WITHDRAWAL SYMPTOMS ARE MAXIMAL WITHIN A FEW DAYS AFTER
CESSATION OF DRUG USE, BUT SUSCEPTIBILITY TO RELAPSE
CONTINUES TO GROW FOR WEEKS TO MONTHS.
• CUES TYPICALLY FAIL TO ELICIT CONDITIONED-WITHDRAWAL.
• CRAVING IS DIFFERENT FROM WITHDRAWAL.
ABERRANT LEARNING(BEYOND PLEASURE AND PAIN)
• CUES THAT PREDICT THE AVAILABILITY OF REWARDS CAN
POWERFULLY ACTIVATE DA CIRCUITRY IN BOTH ANIMALS AND
HUMANS (SCHULTZ, 1998), SOMETIMES EVEN BETTER THAN THE
REWARD ITSELF.
• THEREFORE, THE TRANSITION TO ADDICTION RESULTS FROM THE
ABILITY OF DRUGS TO PROMOTE THIS TYPE OF ABERRANT LEARNING.
MONKEY VTA STUDY (SCHULTZ ET AL, 1990S)
• MONKEYS CLASSICALLY-CONDITIONED
TO ASSOCIATE LIGHT WITH FOOD
• AFTER LEARNING, VTA NEURONS
INCREASE FIRING TO LIGHT INSTEAD OF
FOOD
• DECREASED FIRING IF LIGHT-CUED FOOD
DOESN’T APPEAR
• BASELINE DA = EXPECTED REWARD
• INCREASED FIRING = BETTER THAN
EXPECTED
• REDUCED FIRING = WORSE THAN
EXPECTED
PROBLEMS WITH ABERRANT LEARNING MODELS
• MOST HAVE FOCUSED AT THE LEVEL OF NEURONAL SYSTEMS
• FEW HAVE PROVIDED A PSYCHOLOGICAL STEP-BY-STEP ACCOUNT OF
HOW ABERRANT LEARNING COULD ACTUALLY PRODUCE ADDICTION.
• ARE THE ASSOCIATIONS S-S OR S-R LEARNING? ARE THEY EXPLICIT
OR IMPLICIT?
IMPLICIT LEARNING (TIFFANY, 1990)
• DRUG-TAKING HABITS ARE CAUSED BY ABERRANT LEARNING, BECAUSE
DRUGS SUBVERT NEURONAL MECHANISMS INVOLVED IN IMPLICIT
LEARNING (UNCONSCIOUS S-R OR S-S PROCESSES). URGES AND
CRAVINGS ARE OF SECONDARY IMPORTANCE TO FORCE OF HABIT
(AUTOMATICITY).
• “…WITH SUFFICIENT PRACTICE, PERFORMANCE ON ANY TASK CAN
BECOME AUTOMATIC…” AND “DRUG-USE BEHAVIOR IN THE ADDICT
REPRESENT ONE SUCH ACTIVITY, CONTROLLED LARGELY BY AUTOMATIC
PROCESSES”
• OVER-LEARNED HABITS BECOME SO AUTOMATIC THAT THEY
ESSENTIALLY BECOME COMPULSIVE
PROBLEMS WITH AUTOMATICITY MODELS
• THEY MISTAKE AUTOMATIC PERFORMANCE FOR MOTIVATIONAL
COMPULSION.
• HABITS (BRUSHING TEETH, DRIVING) ARE NOT INTRINSICALLY
COMPULSIVE, NO MATTER HOW AUTOMATIC THEY ARE
• WOULD YOU SACRIFICE YOUR HOME, YOUR JOB, YOUR FRIENDS TO
ENGAGE IN TEETH BRUSHING BEHAVIOR?
• MANY ASPECTS OF ADDICTIVE DRUG PURSUIT ARE FLEXIBLE AND NOT
HABITUAL
INCENTIVE –SENSITIZATION MODEL(ROBINSON AND BERRIDGE, 1993)
• ADDICTIVE DRUGS PRODUCE LONG-LASTING CHANGES IN BRAIN
ORGANIZATION
• THE BRAIN SYSTEMS THAT ARE CHANGED INCLUDE THOSE NORMALLY
INVOLVED IN THE PROCESS OF INCENTIVE MOTIVATION AND
REWARD.
• ADDICTION RENDERS THESE SYSTEMS HYPERSENSITIVE (“SENSITIZED”)
TO DRUGS AND DRUG-ASSOCIATED STIMULI
• THESE SENSITIZED SYSTEMS MEDIATE A COMPONENT OF REWARD
TERMED INCENTIVE SALIENCE OR “WANTING” (NOT PLEASURE OR
“LIKING”).
INCENTIVE SENSITIZATION
• DRUG-INDUCED SENSITIZATION OF BRAIN SYSTEMS (DA) THAT
MEDIATE INCENTIVE-SALIENCE CAUSES DRUGS AND DRUG-
ASSOCIATED STIMULI TO BECOME COMPULSIVELY “WANTED”
• THE ACTIVATION OF THE SENSITIZED SYSTEM CAN OCCUR
BOTH IMPLICITLY OR EXPLICITLY
• THESE SYSTEMS CAN BE DISSOCIATED FROM NEURAL SYSTEMS
THAT MEDIATE THE HEDONIC EFFECTS OF DRUGS (OPIOIDS), I.E.,
HOW MUCH THEY ARE “LIKED” (WANTING IS NOT LIKING).
PSYCHOMOTOR SENSITIZATION• MANY DRUGS PRODUCE PSYCHOMOTOR-ACTIVATING EFFECTS
• AMPHETAMINES, COCAINE, OPIATES, ALCOHOL, NICOTINE, MDMA
• THESE EFFECTS LAST FROM MONTHS TO YEARS AFTER DRUG USE IS
DISCONTINUED
• SOME INDIVIDUALS SENSITIZE READILY, WHEREAS OTHERS ARE MORE
RESISTANT (MAY EXPLAIN SUSCEPTIBILITY TO ADDICTION)
• GENES, HORMONES, STRESS HORMONES, PAST TRAUMA…?
• STRESS CAUSES SENSITIZATION AND MAY BIAS ADDICTION
• ADDICTION MAY MAKE AN INDIVIDUAL HYPERSENSITIVE TO
STRESS
INCENTIVE-SENSITIZATION MODEL
• ADDICTION MAY BE TRIGGERED BY DRUG CUES AS A “LEARNED”
MOTIVATIONAL RESPONSE BUT IT IS NOT A DISORDER OF ABERRANT
LEARNING PER SE
• IT IS A DISORDER OF ABERRANT INCENTIVE MOTIVATION DUE TO
DRUG INDUCED SENSITIZATION OF NEURAL SYSTEMS THAT ATTRIBUTE
SALIENCE TO PARTICULAR STIMULI.
COCAINE CUES STUDY (GRANT ET AL, 1996)
•PET = POSITRON EMISSION TOMOGRAPHY
•RADIOACTIVE MARKER INJECTED
•SCANNER DETECTS LIGHT WAVES FROM DECAY
COCAINE STUDY CONTINUED
•COCAINE ADDICTS AND
CONTROLS SHOWN COCAINE
CUES AND NEUTRAL CUES
•COCAINE CUES IN ADDICTS
ELICITED CRAVING, BRAIN
ACTIVATION
•ACTIVATION CORRELATED WITH
CRAVING IN DORSOLATERAL
PREFRONTAL CORTEX,
AMYGDALA, CEREBELLUM
SMOKING STROP STUDY (GROSS ET AL, 1993)
•NORMAL STROOP EFFECT:
TAKES LONGER TO NAME INK
COLOR WHEN INCONGRUENT
WITH WORD
MATCH
SMOKE
PACK
Smoking
BOARD
PAINT
BRUSH
Neutral
RED
BLUE
GREEN
Congruent
RED
BLUE
GREEN
Incongruent
• Smoking Stroop: 12-hour
abstinent smokers take
longer to name ink color
for smoking words than
neutral words
IMPAIRMENTS IN FRONTOCORTICALFUNCTION
•MAY BE RESPONSIBLE FOR “IRRATIONAL” BEHAVIOR OF ADDICTS
•POOR DECISION-MAKING
•MAY EXACERBATE INCENTIVE-SENSITIZATION
HOPEEG HOSPITAL FOR ADDICTION TREATMENT
•CONTACT US
•HTTP://HOPEEG.COM/
•00201008968989