PSYC 357 Test 4

What is addiction?

Difficulty controlling behavior aimed at a specific target

• Goes against natural selection, intentionally engaging in self-destructing behavior

• Encompasses variety of stimuli

What is the most prevalent and problematic substance?

Alcohol

Addiction varies by both…

Culture and sex

• Men are more susceptible to addiction

What is the lifetime prevalence of those with alcohol addiction or dependency in America? What about point prevalence?

• 29% for lifetime prevalence

• 10% for point prevalence

Point vs. lifetime prevalence

• Point prevalence: How many people are dependent on alcohol right now?

• Lifetime prevalence: How many people have ever been dependent on alcohol in their lifetime?

How many substances does the DSM classify under use disorders?

17 different substances

• Little variation in basic criteria

Generally, what are the symptoms of withdrawal?

The opposite of the substance’s pleasurable effects

3 parts of the brain-reward system

Ventral tegmental area (VTA), nucleus accumbens, and the medial forebrain bundle

Repeated use of the brain-reward system results in…

Homeostatic neuroadaptation (downregulation)

• Less NT released

What is anhedonia? What neurotransmitter is typically involved?

Lack of pleasure, considered a mild form of depression

• Common to all recreational drug withdrawal

• Dopamine is typically involved

What is stage 1 of addiction?

Binge / intoxication

• Primarily dopamine / opioid system, built to reward good behavior

• Repeated use causes downregulation

• Positive reinforcement of behavior (drugs feel good)

What is stage 2 of addiction?

Withdrawal negative affect

• Stress hormones released with extended period of abstinence

• Opposite symptoms than what the drug was creating

• Negative reinforcement —> using substances to avoid negative effects

What is stage 3 of addiction?

Preoccupation / anticipation

• Involves the prefrontal cortex

• Driven by withdrawal symptoms + classical conditioning

• Substances and stimuli become powerfully paired

  • Exposure to CS evokes strong cravings (priming effect)

How is alcohol consumption studied in rodent models?

Via consumption ratios

• Rats offered water bottle vs. alcohol bottle

• If consumption of alcohol is over 50%, it shows preference

What is the best percentage of alcohol, in terms of preference in animal models?

4%

Inbred P rats symptoms

• Will consume to intoxication

• Will work for alcohol

• Consume for the psychoactive effects

• Experience withdrawals and relapses

Alcohol naive P rats definition and symptoms

Offspring but have never been exposed to alcohol

• Lower serotonin and dopamine levels

• Higher GABA terminals and opioid receptors