Impulsivity and
Alcohol Use Disorders
Robert F. Leeman, Ph.D.
Department of Psychiatry
Yale School of Medicine
VA (New England) VISN1 Mental Illness Research
Education and Clinical Center (MIRECC)
Serious Alcohol Problems
 Relatively common
 Within prior year (current): 11%
– Males: 15%
– Females: 7%
 Costly: $185 billion/year in U.S.
 Lethal: 3rd leading modifiable cause
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Contributing Factors
 Multiple factors → alcohol problems
 Some before heavy drinking begins
 Detect early factors for prevention
 Impulsivity an example of risk factor
–Earlier onset of alcohol use
–More severe alcohol problems
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Onset of Use & Problems
 Drinking usually begins in teens
 Heaviest drinking: 18-25 yrs
– ~65% use in past month
– ~45% > 4/5 drinks/evening → risky
 ~18% young adults alcohol problems
 ↑ Impulsivity → ↑ problems
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Lecture Covers
 Definitions
 Key characteristics & neurobiology
 Problems, other conditions, course
 Implications: prevention & treatment
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Case 1: Phineas Gage
 Railroad worker
 Conscientious, mild manner,
hard-work
 Accident → steel rod pierced head
 Changes in personality
– Profane, ↓ restraint: give in to desires
– Frequent changing of plans
 Role of key brain regions in impulsivity
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Case 2: Law Student
 Prior DUI arrests
 Participating in research project
 Party: “spiked Gatorade”
 1st day license: drives after ~4 drinks
 Impulsivity contribute to problems?
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Lecture Topics
 Definitions
 Key characteristics & neurobiology
 Problems, other conditions, course
 Implications: prevention & treatment
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Alcohol Use Disorder (AUD)
 Recurring problems
 Affecting multiple life areas
 DSM-5: > 2 criteria, past 12 mo.
 Diagnosis associated with:
–Long-term alcohol problems
–Earlier death
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AUD Criteria
– ↓ Role obligations
– Tolerance
– Hazardous use
– Withdrawal
– Strong craving
– ↑ Amount/time use
– Interpersonal problems
– Desire/inability to ↓ use
– Use despite problems
–↓ Other due to use
–↑ Time obtain/use/recover
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Impulsivity: Usual Definition
 Acting rashly/without thinking
 Repeated bad decisions
 Recurrent out of control behavior
 Trouble frequently without planning
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Impulsivity: Research Definition
 Rapid, unplanned reactions
 Diminished regard for outcomes
 Not really 1 thing
 More a class of characteristics
 2 main types: response, choice
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Response Impulsivity
 Difficulty suppressing
actions
 Ramifications include:
–Alcohol/cues = a strong impulse
–Failure plan for future: Rx impact
–Hard to maintain behavior change
–Emotions can ↓ drinking control
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Choice Impulsivity
 Immediate, definite
rewards
 Ramifications include:
–Alcohol: immediate definite reward
–Abstinence: weak, uncertain
–Hard to see future improvement
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Ways to Measure
 Cognitive tasks (computer)
 Clinical interviews
 Self-report questionnaires
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Cognitive Tasks
 Stop-signal tasks
–Respond to visual cue
–No response if hear auditory cue
 Continuous performance tasks
–Respond to most cues (e.g., letters)
–Not to 1 cue (e.g., letter “X”)
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Clinical Interviews
 For conditions related to impulsivity
 Childhood interviews: ADHD
– Parent/teacher ratings: attention
– E.g. child task: wait to eat cookie
 Adolescent/adult structured interviews
– SCID
– Conditions like bipolar disorder
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Questionnaires
 Response: impulsive behavior scale
– Lack planning and perseverance
– Rash response to +/- emotions
 Choice: monetary choice questionnaire
– Choices: hypothetical $ payments
– Now vs. later
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Back to Cases
 Case 1: Phineas Gage
–Response: ↓ restraint
–Choice: inability to adhere to plans
 Case 2: law student
–Response: didn’t stop drinking
–Choice: drink(immediate), DUI(later)
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Lecture Topics
 Definitions
 Key characteristics & neurobiology
 Problems, other conditions, course
 Implications: prevention & treatment
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Observable Early in Life
 Observable by age 8:
– Fidgety
– Trouble attention, directions
– Talking/acting out of turn
– Unpredictable/explosive behavior
 Predictive value: early alcohol onset
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Genetic Predisposition
 Impulsivity: ~ 50% explained genes
 Alcohol : ~ 50% explained genes
 Alcohol & impulsivity genes overlap
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Key Brain Regions
Dorsal
striatum
Frontal
lobes
Ventral striatum
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Brain: Frontal Lobes
 Ventromedial prefrontal cortex(vmPFC)
– Response inhibition
– Decision-making
 Orbitofrontal cortex(OFC)
– Linked to limbic system (reward)
– Impulse control
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Back to Phineas Gage
• Frontal lobes
- severe injury
- vmPFC, OFC
• Impulsive after
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Brain: Striatum
 Ventral
–Nucleus accumbens
Caudate
–Reward anticipation
 Dorsal
–Caudate and putamen
–Habit formation
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Lecture Topics
 Definitions
 Key characteristics & neurobiology
 Problems, other conditions, course
 Implications: prevention & treatment
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Relationship to AUD
 ~25% higher impulsivity scores
 Impulsive child (detectable early)
 ~ 80% ↑ heavy drinking risk
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Alcohol → Impulsivity
 Alcohol ↑ impulsivity over time
–Frontal lobe volume loss in adults
–↓ White matter integrity, adolescents
 Alcohol ↑ impulsivity acutely
–Intoxicating dose → 70% ↑ errors
–↑ preference for definite rewards
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Back to Case
Case 2: law student
–Impulsive child: fidgety, ↓ attn span
–Early alcohol onset: pre-high school
–AUD by early adulthood
–Alcohol acutely ↓ ability resist driving
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Other Psychiatric Disorders
 Attention Deficit Hyperactivity (ADHD)
– ~ 60% ↑ Impulsivity score than without
– ~ 2 x ↑ AUD risk than without
 Bipolar disorder: ↑arousal & depression
– ~ 70% ↑ Impulsivity score than without
– ~ 4 x ↑ AUD risk than without
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Lecture Topics
 Definitions
 Key characteristics & neurobiology
 Problems, other conditions, course
 Implications: prevention & treatment
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Prevention
 Treatment challenging/$/time consuming
 Prevention/early intervention preferable
 Personality-based intervention
1. ID students with high impulsivity
2. Goals, ↑ motivation change coping
3. ID negative coping & relation to alcohol
4. Evidence ↓ probability heavy drinking
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Psychosocial Treatments
 Response impulsivity
–Teach/practice coping urges, pass
–Train improve focus, ↓ distractions
 Choice impulsivity
–↑ interest non-alcohol rewards
–↓ interest in immediate rewards
–↑ interest in long-term rewards
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Pharmacologic Treatment
 Relation to AUD and impulsivity
–↓ Alcohol use, ↓ impulsivity
–Some pharm. direct evidence
 Examples with evidence:
–Opioid antagonists
 Naltrexone
 Nalmefene
–Varenicline
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Opioid Antagonists
 Naltrexone FDA approved alcohol
 Bind to/block receptor activation
 Efficacy: ~ 25% ↓ drinking days
 Decreases rewarding effects
 ↓ choice impulsivity, ICD efficacy
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Varenicline
 FDA approved: nicotine
 Partial agonist
– Binds strongly to nicotine receptors
– Triggers partial response
– Block full alcohol/nicotine response
 Efficacy: ~20% ↓ heavy drinking
 Decreases rewarding effects
 Improves relevant cognition
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Conclusions
 Two main types
– Response impulsivity
– Choice impulsivity
 Strong genetics, early manifestation
 Measurable behavioral, brain activity
 ↑ impulsivity, ↑ risk AUD development
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Conclusions
 Important for prevention & treatment
– Can identify impulsivity before AUD
– Opportunity for early intervention
– Measure ↓ impulsivity—intervention
– Psychosocial/pharm ↓ impulsivity
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