Addiction I & II

Question 1

Definition of substance use disorders

Answer 1

• 11 criteria including e.g.:
  
  • substance taken in large amounts/long period
  • unable to cut down/control substance use
  • ==> social/interpersonal problems
  • tolerance or withdrawal
• mild: 2-3 sx
• moderate: 4-5 sx
• severe: 6+ sx

Question 2

Neurobiology of substance abuse

Answer 2

• multiple brain regions involved
• motivational systems/reward:
  
  • ventral tegmental area ==>
  • nucleus accumbens
• frontal regions/prefrontal cortex
  
  • learning, cognitive control, inhibition
• mood and stress reactivity
• all substances of abuse ==> dopamine release @ nucleus accumbens

Question 3

Medications available to treat alcohol abuse

Answer 3

• disulfiram (Antabuse)
  
  • inhibits acetaldehyde dehydrogenase
  • ==> antabuse rxn
• Naltrexone
  
  • opiod antagonist
  • (possibly) blocks euphoria from alcohol
• Acamprosate
  
  • enhances GABA transmission
  • interferes w/glutamate transmission
  • possible restoration of GABA/glutamate balance

Question 4

Medications available to treat opioid abuse

Answer 4

• methadone
  
  • long-acting opioid agonist
  • doesn’t always lead to complete abstinence, but reduces harm and increases positive outcomes
• buprenorphine
  
  • partial opioid agonist/naloxone
  • can precipitate w/drawal
• naltrexone
  
  • blocks effects of heroin
  • can precipitate withdrawal

Question 5

Medications available to treat tobacco abuse

Answer 5

• NRT
  
  • can lead to rash, tachycardia
• Buproprion
  
  • nicotinic receptor antagonist
  • dopamine reuptake inhibitor
  • doubles quit rates
• Varenicline
  
  • partial alpha₄beta₂ agonist
  • some reports of depression/suicidal ideation

Question 6

Psychosocial tx of substance abuse

Answer 6

1. Contingency management
2. Motivational interviewing
3. Cognitive behavioral therapy
4. Twelve step facilitation

Question 7

Contraindications of Disulfram (Antabuse use)

Answer 7

• Risk for MI
• Risk for CVA
• Cognitive dysfunction (can’t remember what will happen if drinks)
• Pregnancy

Question 8

“free-will” vs. biological disease in substance abuse disorders

Answer 8

• All drugs of abuse share the final common pathway of increasing dopamine release in the nucleus accumbens; associated with the “high” (reward reinforcement)
• Over time, dopamine circuitry compensates so that individuals now have to use drugs to create physiological normal levels of dopamine
• Orbitofrontal cortex
  
  • SUD patients have decreased response-reversal learning, mediated by the OFC; i.e. they do not learn to alter their behavior when behavior that was previously rewarded/reinforced is now punished

Question 9

Age impact on development of SUD

Answer 9

• brain circuits involved:
  
  • dopamine-reward sytem ==> reinforcement of SUD
  • prefrontal cortex ==> resists development of SUD
• circuits ==> susceptability of teenage development of SUD b/c reward system is fully developed while prefrontal cortex is not

Question 10

Factors that impact SUD

Answer 10

• Substance availability
• Pharmacological reinforcement (e.g. withdrawal ==> reinforced substance use)
• History of prior substance abuse
• Genes
• Gender (M>F by time young adulthood is reached)
• Age (Teenagers = susceptible)
• Risk-taking disposition
• Stress
• social punishment/reinforcement

Question 11

Genetic impact on SUDs

Answer 11

• ~ 50% heritability (based on twin and adoption studies)
• First degree relatives w/SUD ==> higher rates of SUD
• Rats can be bred to create lines that are highly susceptible to drug addiction

Question 12

Important screening tools for SUDs

Answer 12

• AUDIT (Alcohol Use Disorder Identification Test)
  
  • “At Risk Drinking”
  • Men: > 5 standard drinks in a day, or >14 per week
  • Women: > 4 in a day or >7 per week