1. Translational Research on
Reinforcement as a Determinant of
Substance Use Disorders
Stephen T. Higgins, Ph.D.
University of Vermont
• Substance use disorders (SUDs) represent a
tremendous public health problem in the U.S.,
Europe, and most contemporary societies.
• A great deal more needs to be learned regarding
the determinants of SUDs and how to more
effectively prevent and treat these disorders.
• Also important is that we fully explore and, when
possible, translate scientific information that is
already available into clinical interventions for
3. Introduction (cont’d)Introduction (cont’d)
Extensive evidence indicates that reinforcement
plays an important role in the genesis,
maintenance, and recovery from SUDs.
Reinforcement is a process wherein a stimulus
event increases the future probability of a
response (drug use) by acting as a consequence.
The neurochemical and neuroanatomical
systems involved in drug-produced reinforcement
have been relatively well characterized (i.e.
mesolimbic dopamine system).
4. Introduction (cont’d)Introduction (cont’d)
This is among the most important observations in a
scientific analysis of SUDs because it places them
within an existing body of knowledge in the
behavioral and biological sciences.
Stated in its most parsimonious form, SUDs are
controlled, at least in part, by the Law of Effect.
This knowledge has been utilized well in pre-clinical
research on SUDS, but less consistently so in
clinical research and application.
5. Clinical Research on the Role ofClinical Research on the Role of
Reinforcement in Substance Use DisordersReinforcement in Substance Use Disorders
There’s a resurgence of interest in the
clinical implications of reinforcement as a
determinant of SUDs
The research illustrates two main
empirical generalizations with important
conceptual and practical implications:
1. Drug use is a form of operant
behavior (i.e., sensitive to
2. The reinforcing effects of drugs are
malleable and dependent on
6. Evidence to Support ThoseEvidence to Support Those
Empirical GeneralizationsEmpirical Generalizations
• Laboratory settings
• Treatment settings
7. Drug self-Administration StudiesDrug self-Administration Studies
Two experiments examining the influence of
alternative, non-drug reinforcers on preference for
cocaine use illustrate the context-dependent nature of
the reinforcing effects of drugs.
• Higgins et al. (1994): recreational users of
cocaine hydrochloride made exclusive choices
between (1) cocaine vs. placebo and (2)
cocaine vs. varying amounts of money
• Hatsukami et al. (1994): crack cocaine abusers
chose between smoking cocaine vs. earning
tokens worth varying monetary values
• Same functional relationships demonstrated with all
routes of cocaine use, a wide-range of drug-use
histories and doses, as well as other drugs (e.g.,
heroin, cigarette smoking).
• Contingent availability of non-drug, alternative
reinforcers can significantly alter the probability of
9. Another Contextual Factor:Another Contextual Factor:
Temporal DelaysTemporal Delays
In naturalistic settings individuals often
choose between using drugs and enjoying
their effects in the present versus abstaining
now and reaping delayed positive
consequences for doing so in the future.
Roll et al. (2000) illustrates the influence of
delays: Regular cigarette smokers
abstained from smoking for several hours
and then chose between puffs on a cigarette
vs. varying amounts of money available after
varying temporal delays.
10. Constraints on Drug ConsumptionConstraints on Drug Consumption
Studies emphasized the influence of
alternative reinforcers, but relationships can
be considered more generally in terms of
constraints on drug use (behavioral
As constraints on drug use increase, in
terms of price, effort, or opportunity cost,
consumption decreases; as constraints
decrease (low price or little opportunity
cost), consumption increases (i.e., Law of
11. Discounting of Delayed ConsequencesDiscounting of Delayed Consequences
Emerging area of behavioral economics research
suggests that those with substance use disorders
discount the value of delayed reinforcement more
than those without substance use disorders (Bickel
& Marsch, 2001)
More specifically, abusers show bias for (a) more
immediate, smaller reinforcers over more delayed
larger reinforcers and (b) more delayed, larger
losses over more immediate, smaller losses.
12. Seminal StudySeminal Study
Study by Madden et al. (1997) illustrates the procedure
Opiate-dependent outpatients and community
volunteers made a series of choices between two
hypothetical monetary options or drug options (patients
- Monetary values: $1 to $1,000
- Drug doses: comparable # and units to money
- Delay intervals: 7 intervals ( 1 week-25 yrs)
- 1st choice between highest value available immediately or in
At least 14 original studies demonstrating
increased discounting of delayed reinforcement in
abusers, and similar outcomes were obtained
using real vs. hypothetical consequences.
Co-morbid problems are associated with increased
Whether the greater discounting represents a
cause or consequence of substance use disorders
14. Treatment SettingsTreatment Settings
Treatments based on reinforcement principles
• increase the availability and reduce
constraints on reinforcement from non-drug
• increase constraints on reinforcement
derived from substance use and related
• configure these efforts to accommodate the
relatively short temporal horizons
characteristic of substance abusers.
15. Contingency ManagementContingency Management
CM involves systematic delivery of
reinforcing or punishing consequences
contingent on occurrence of a target
Most common CM in SUDs literature is
voucher-based reinforcement of recent drug
Illustrate with studies with cocaine-
dependent outpatients and pregnant
cigarette smokers and then summarize with
results from recent meta-analysis.
16. TREATMENT PROCEDURES
Weeks 1-12: Twice weekly counseling and
thrice weekly urinalysis,
Weeks 13-24: once weekly counseling and twice
Months 7-12: Aftercare--once monthly check-in
with counselor and random urinalysis.
Vouchers, reciprocal relationship counseling,
functional analysis, vocational assistance, after
recreational/social practices, monitored
17. Voucher Program
(weeks 1-12 only)
• Specimens that were negative for
benzoylecgoine earned pts recorded on
vouchers. Pts were worth equiv. of $.25
• 1st neg. test = 10 pts @ $.25/pt = $2.50.
Value of vouchers for each subsequent
consecutive negative test increased by 5 pts;
e.g., 2nd = 15 pts, 3rd = 20 pts, etc.
• Equivalent of $10 bonus earned for every 3
consecutive negative tests.
18. Voucher Program (cont’d)
(weeks 1-12 only)
• Cocaine-positive tests or failure to give a
specimen reset vouchers back to initial value
• 5 consecutive negative tests returned vouchers
back to the value preceding reset
• Vouchers were exchangeable for retail items in
community; max. earnings possible = $997.50
• No cash was ever given to patients
• All purchases were made by staff and had to be
deemed by therapists to be consistent w/CRA
19. COMMUNITY REINFORCEMENT
• Practical needs
• Social & recreational counseling
• Skills training
• Relationship counseling
• Vocational counseling
• Other drug use (monitored disulfiram therapy)
21. Achieving Cocaine Abstinence With a Behavioral Approach
Stephen T. Higgins, Ph.D, Alan J. Budney, Ph.D, Warren K. Bickel, Ph.D,
John R. Hughes, M.D., Florian Foerg, B.A., and Gary Badger, M.S.
Objective: The authors compared the efficacy of a multicomponent behavioral treatment
and drug abuse counseling for cocaine-dependent individuals. Method: The 38 patients
were enrolled in outpatient treatment and were randomly assigned to the two treatments.
Counseling in the behavioral treatment was based on the disease model of dependence
and recovery. Patients in the behavioral, but not the drug counseling, treatment also
received incentives contingent on submitting cocaine-free urine specimens. Results: Of
the 19 patients who received behavioral treatment, 58% completed 24 weeks of treatment,
versus 11% of the patients achieved at least 8 and 16 weeks of documented continuous
cocaine abstinence, respectively, versus 11% and 5% in the drug abuse counseling group.
Conclusions: This multicomponent behavioral treatment appears to be an effective
intervention for retaining outpatients in treatment and establishing cocaine abstinence.
(Am J Psychiatry 1993; 150:763-769)
22. TRIAL COMPARING BEHAVIORAL
VS STANDARD CARE
• Standard drug abuse counseling based on
disease model and 12-steps
• 38 cocaine-dependent subjects randomized to
two treatments (19/gp.)
• 6 months treatment and 6 months of follow-up
24. Incentives Improve Outcome in Outpatient
Behavioral Treatment of Cocaine
Stephen T. Higgins, Ph.D; Alan J. Budney, Ph.D; Warren K. Bickel,
Ph.D; Florian E. Foerg; Robert Donham, MA; Gary J. Badger, MS
Reprinted from the Archives of General Psychiatry
July, 1994 Volume 51
Copyright 1994, American Medical Association
• 40 pts. Randomly assigned to one of two treatment
• Treatment duration was 25 wks for both groups. 2x
weekly counseling and 3x weekly urinalysis in weeks
1-12; reduced to 1x weekly counseling and 2x
weekly urinalysis in weeks 13-24.
• Counseling in both groups was identical and based
on the Community Reinforcement Approach (CRA)
Only difference between groups was one group
received vouchers contingent on cocaine-negative
urinalysis results in weeks 1-12. During weeks 13-
24, both groups received only a single $1 Vermont
State Lottery ticket/cocaine-negative test.
26. Treatment RetentionTreatment Retention
Weeks of Treatment
28. Contingent Reinforcement Increases Cocaine Abstinence
During Outpatient Treatment and 1 Year of Follow-up
Journal of Consulting and Clinical Psychology
2000, Vol. 68, No. 1, 64-72
Copyright 2000 by the American Psychological Association, Inc
0022-006X/00/$5.00 DOI: 10.1037//0022-006X.68.1.64
Stephen T. Higgins, Conrad J. Wong, Gary J. Badger, Doris E. Huag Ogden, and Robert L. Dantona
University of Vermont
This study assessed whether contingent incentives can be used to reinforce cocaine abstinence in
dependent outpatients. Seventy cocaine-dependent outpatients were randomized into 2 conditions.
All participants received 24 weeks of treatment and 1 year follow-up. The treatment provided to all
participants combined counseling based on the community reinforcement approach with incentives
in the form of vouchers exchangeable for retail items. In 1 condition, incentives were delivered
contingent on cocaine-free urinalysis results, whereas in the other condition incentives were
delivered independent of urinalysis results. Abstinence-contingent incentives significantly increased
cocaine abstinence during treatment and 1 year of follow-up compared with noncontingent
• 70 cocaine-dependent adults
• Randomized to two treatments
All get CRA + vouchers
• Only difference is one gp. gets vouchers
contingent on cocaine abstinence, while other
gp. gets them non-contingently (yoked
• 24 weeks treatment and 1 year of follow-up
32. Voucher-Based Incentives to
Treat Pregnant Smokers
• Maternal smoking is the most important
preventable cause of poor pregnancy outcomes
in the U.S.
• Approx. 30% of women of childbearing age in
U.S. are smokers. Among smokers, 20%
discontinue smoking upon learning of
pregnancy, but vast majority smoke through the
• Effective cessation interventions are available,
but quit rates are low (15-18%), and have been
at that level for almost 2 decades.
33. Voucher-Based CM WithVoucher-Based CM With
Pregnant SmokersPregnant Smokers
Seminal study in application to pregnant
smokers: Donatelle et al. (2000). Tobacco
Control, 9, iii67-iii69.
Our group followed up: Higgins et al. (2004)
Nic & Tob Res, 6, 1015-1020; Heil et al., in
34. Donatelle et al., 2000.Donatelle et al., 2000.
Women randomized to usual-care (n=108) or
voucher condition (n=112).
Abstinent-contingent $50 voucher available
monthly for pregnant smoker, and $50 for 1st
month and $25 thereafter for S0.
Contingency in effect through pregnancy and 2
Quit rates: End-of-pregnancy 32% vs. 9% and 8
wks postpartum 21% vs. 6%.
35. A Pilot Study on Voucher-Based
Incentives to Promote Abstinence from
Cigarette Smoking During Pregnancy
Stephen T. Higgins, Ph.D., Sarah H. Heil, Ph.D.,
Laura J. Solomon, Ph.D., Jennifer Plebani Lussier, Ph.D.,
Rebecca L. Abel, B.S., Mary Ellen Lynch, R.N.
Gary J. Badger, M.S.
University of Vermont, Burlington VT, USA
• During initial five days (M-F) of quit attempt
women submit daily breath COs (abstinence
criterion < 6 ppm).
• Beginning on day 8, contingency moves to
urine cotinine (< 80 mg/ml), thereby requiring
less frequent monitoring.
• Contingency operates through the pregnancy
and for 3 mos. postpartum . Total possible
earning $1,146 ($786 pregnancy, $360
• Pilot data from 58 consecutive admissions.
37. Abstinence RatesAbstinence Rates
(S-R + biochemical verification)(S-R + biochemical verification)
End of AP 3 mo PP 6 mo PP
(Higgins et al., 2004).
38. Fully-Randomized TrialFully-Randomized Trial
Methods largely same as pilot study.
82 women entered; 5 excluded due to fetal
demise; 37 in contingent and 40 in
Only differences from pilot are in random
assignment and exclusive reliance on urine
cotinine (some use of salivary cotinine in
39. Abstinence RatesAbstinence Rates
(S-R + biochemical verification)(S-R + biochemical verification)
End of AP 3 mo PP 6 mo PP
40. Voucher-Based Reinforcement
Therapy for Substance Use
Disorders: A Quantitative Review
J.P. Lussier, S.T. Higgins, S.H. Heil,
G.E. Badger, and J. Mongeon
University of Vermont
• Effect sizes & 95% CI calculated for controlled
studies on voucher-based reinforcement therapy
(VBRT) published between 1/91 & 3/04.
• 65 studies reviewed, including 40 where effects
of contingent vouchers were experimentally
• Focus was on period when vouchers were
• Studies grouped by moderator variables: type of
drug targeted, control, duration of VBRT,
voucher $ value, voucher delivery immediate or
delayed, study setting.
42. Summary / ConclusionsSummary / Conclusions
Extensive evidence that reinforcement plays a
central role in the genesis, maintenance, and
recovery from SUDs.
Clinical lab research outlines contextual factors
critical to understanding vulnerability to and
treatment of SUDs.
Observations are framed in terms that have
continuity across species and support a common
conceptual framework from the lab to the clinic.
Treatment outcome studies illustrate how
reinforcement principles can be translated into
efficacious interventions, while also providing
opportunities for conceptual considerations.
43. Summary/Conclusions (cont’d)Summary/Conclusions (cont’d)
Consider the women who continues smoking
despite being pregnant, but quits with a voucher-
Perplexing until you consider that:
- Pregnant smokers In U.S. predominately lower SES (fewer
- Material feedback on health of fetus is delayed
- Women are drug dependent, which is associated with steeper
discounting of delayed rewards
- Cessation increases nicotine withdrawal
- Smoking produces relatively immediate reinforcing effects
- Vouchers bridge the temporal gap to healthy fetus and change
the ratio of reinforcement from drug vs. non-drug activities.
44. Summary/Conclusions (cont’d)Summary/Conclusions (cont’d)
Continuing to examine how reinforcement principles
operate in all aspects of substance use and, where
possible, translating that information into clinical
interventions has much to offer an evidence-based
approach to treatment and prevention of SUDS.